Student guest post: Seasonal Flu Vaccine: Why we need it

It’s time for this year’s second installment of student guest posts for my class on infectious causes of chronic disease. Fifth one this year is by Nai-Chung Chang. 

Of the many health problems that everyone is bound to have at some point, influenza, or just “the flu,” is one of the most prominent. In fact, we call the time during which it is most prevalent the “flu season”. It has now become a regular occurrence in the U.S. to just get a shot before the flu season hits, and be free of it for the rest of the year. In some cases, like me, people just decide not to get the vaccine at all. I say to myself all the time: “It is just the flu. If I do get it, I’ll just take a nap, and I’ll be fine.” However, there are serious complications with influenza if the individual is afflicted with certain diseases, making the vaccine a necessity. Even in the general population, influenza infections could lead to serious health problems, at a lower rate, that could complicate the daily lives of individuals.

Influenza is a generic description of a variety of strains of influenza viruses, including influenza A (H1N1, H3N2), and influenza B. It is a widespread virus, and can infect both human and animals, albeit with different strains. (1) The influenza virus is difficult to completely control since it constantly undergoes different changes through antigenic drifts and shifts, small and abrupt changes in the virus constructs, respectively. (2) It causes fever, coughs, sore throat, runny nose, and a host of other symptoms that target different parts of the body. In extreme, severe cases, it may cause the death of the infected individuals. It can spread from person to person up to 6 feet away through coughing and sneezing, spraying droplets containing infectious particles into the air. The droplets either lands in the other individual’s mouth, or is inhaled into the lung. Influenza is very contagious, due to the fact that it can infect others prior to the development of symptoms, as well as a period after. In addition, there exist asymptomatic carriers that can infect others without knowing. There are vaccines provided every year prior to the start of the “flu season:” a period of time in which the population is most likely to acquire the disease. Once the symptoms develop, it can be treated with antiviral medicine, such as Tamiflu (oseltamivir) and Relenza (zanamivir).

In addition to the problems that a regular influenza infection can cause, in individuals with certain diseases, complications could develop from the interaction between the influenza virus and the disease currently affecting the patient. In asthma patients, the attacks are often triggered by respiratory virus infection, whether by the virus particle itself or the inflammation resulting from the influenza symptoms. Also, the influenza viruses could augment natural responses to allergenic particles resulting in a more severe than normal attack; influenza patients with asthma are often hospitalized as the result. (3) In patients with cardiovascular disease, influenza infections represent a high level risk. The infection could destabilize existing plaques (blocks in the artery) in atherosclerotic patients. In addition to the acute responses from the destabilization, influenza infections could also induce chronic inflammation in the body, as well as reduced clotting ability. (4) For patients with diabetes, infection with influenza represents a high risk of hospitalization and death. In diabetics, the immune system is weakened, making it difficult to fight of the disease. In addition, the infection can cause fluctuation in the level of blood sugar in the patients, through natural immune responses, or lack of desire to eat due to the effects of the influenza symptoms. There is also an increased risk of acquiring pneumonia as a complication of the infection. (5) As in the case with diabetics, patients with cancer and HIV/AIDS are also likely to have complications due to weakened immune systems from both treatment and disease.

From the variety of complications that could result from influenza infections, one can now see that it is extremely important for an individual to receive the vaccines when available. In some places, vaccines are often offered free of charge, especially in workplaces that have high exposure risks, such as hospitals and research facilities. In addition to reducing the likelihood of being affected by influenza, flu vaccines have shown to have reduced the development and progression of other diseases such as chronic obstructive pulmonary disease (COPD). (6) For individuals with HIV/AIDS, vaccines are especially important since they are more vulnerable to infections. In addition, they must be aware of the type of vaccines they are using, since certain vaccines do not work sufficiently in people with immune-deficient issues. However, there exist other treatments for the prevention of the disease, such as chemoprophylaxis, that would allow these individuals to be properly protected against possibilities of infection. (7) With the prevalence of the influenza virus in both the U.S. and globally, it is important that an individual keep up with the most current vaccines, as they are designed to combat the most common forms that would appear that flu season, since the strains changes every year.


  1. CDC. Seasonal Influenza (Flu).
  2. CDC. How the Flu Virus Can Change.
  3. Glezen, W. Paul. Asthma, influenza, and vaccination. Journal of Allergy and Clinical Immunology 188(6): 1199-1206.
  4. Madjid M, Nagahvi M, Litovsky S, Casscells SW, Influenza and Cardiovascular Disease. Circulation 108:2730-2736.
  5. CDC. Flu and People with Diabetes.
  6. Poole PJ, Chacko E, Wood-Baker RWB, Cates CJ. Influenza vaccine for patients with chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews.
  7. CDC. HIV/AIDS and the Flu.

Student guest post: Cholesterol, a bacterium, and gallbladder cancer

It’s time for this year’s second installment of student guest posts for my class on infectious causes of chronic disease. Fourth one this round is by Kristen Coleman. 

If you are anything like me, you have been told countless reasons over the years why we must watch what we eat, keep our cholesterol intake down, and try to work out. It shouldn’t really come as a surprise then that I, since I am a public health student after all, aim to convince you of yet another reason why a healthy diet and exercise are valuable. What is this huge reason to avoid Big Macs and think about taking the stairs instead of the elevator you ask? Well, it may help you to prevent gall bladder cancer, is all.

All of this begins with gallstone formation. Gallstones are hard deposits, usually of cholesterol, that become lodged in your gallbladder over time. Your gallbladder is an organ that helps to aid in digestion through the storage and release of bile which helps to break down fats in your small intestine. The gallbladder is located on the right side of the body attached to the liver. The process of gallstone formation is called cholelithiasis. In this process, cholesterol, which is not very soluble, becomes clustered together in droplets in the bile called micelles. This cholesterol droplet then hardens into the crystals that make up a gallstone. Obesity causes bile to transit the gallbladder less rapidly and increased cholesterol in the diet means there is more cholesterol available to form stones. It does not require and active imagination then, to understand how obesity and high cholesterol intake contribute to stone formation, but how does this all tie into cancer you ask?

It all comes down to infection with a bacterium known as Salmonella typhi. Yes, this is the same bacterium that causes Typhoid fever and was the malady that afflicted the famous Typhoid Mary. While many people may become infected with S. typhi over the course of their lives, those individuals with gallstones are 6-15 times more likely to become carriers of S. typhi in the gallbladder. This is important because those people with a chronic infection of S. typhi have been shown to have 3-200 times higher risk of developing gallbladder cancer then non-carriers. Furthermore, chronic carriers have a 1-6% lifetime risk of developing gallbladder cancer. In fact, gallbladder cancer is so linked to S. typhi infection that gallbladder removal, called cholecystectomy, is recommended for those people with gallstone disease who live in high risk areas. Where is a high risk area? Most developing countries of the world are high risk areas for S. typhi, especially countries in Asia, Africa, and Latin America. This means that travelers from the USA and other developed countries to these regions are at risk for developing the infection. However, even at home in the USA, low risk doesn’t mean no risk, and we should be vigilant against emergence of this bacterium.  

In conclusion for all my gallbladder-containing friends out there (I make this distinction because I, myself, am no longer at risk for gallbladder cancer since I had mine removed in 2006 after a bout with gallstone disease) stay aware of your cholesterol levels and pay attention to making sure you have a healthy diet because, like every health care professional will tell you, it might just save your life….perhaps in a way you don’t expect!


  1. University of Maryland Medical Center. Gallstones and gallbladder disease. Online
  2. Ferreccio, Catterina. Salmonella typhi and Gallbladder Cancer.

Center for Disease Control online source.

Student guest post: Challenges and Progresses in HIV Vaccine Research

It’s time for this year’s second installment of student guest posts for my class on infectious causes of chronic disease. Third one this round is by Jack Walsh. 

The Human Immunodeficiency Virus (HIV) infection is one of the most significant global health challenges of this 21st century. Since the isolation of the virus in 1983, it has infected 70 million people among whom 35 million have died of Acquired Immunodeficiency Syndrome (AIDS).1 Although important progresses have been made in slowing down the pandemic and reducing the morbidity and mortality related to HIV/AIDS with the highly active antiretroviral therapy (HAART) drugs, there are still difficulties in stopping the dissemination of the infection. It is estimated that for every person gaining access to HART, there are two new others infected by the virus.2 An effective and safe vaccine is therefore needed to prevent HIV from spreading, but the development of the vaccine has been proven to be an enormous scientific challenge.

HIV presents particularities that make it very difficult for researchers to find a vaccine. It is a lentivirus from the Retroviridae family, slowly progressive using an enzyme (called reverse transcriptase) for the transformation of its genome or genetic material (RNA in this case) into a new one (proviral DNA) integrated in that of the human host using another enzyme known as integrase. One of the most fascinating characteristics of the virus is its genetic variability in both an infected individual and geographically. In a same person, new mutations can be introduced in almost every new copy, creating up to millions of new particles every day. One antibody could then neutralize one virion, but not another.3 Additionally, super-infection in an individual already HIV infected results in new recombinants increasing further viral genetic diversity. The virus also presents two different types, HIV-1 worldwide and HIV-2 confined to West Africa. HIV-1 is further subdivided into subtypes or clades differently distributed on the globe and further diversified within each clade. Moreover, by integrating proviral DNA in the genome of memory cells of the immune system (CD4+ T cells) the HIV can escape the immune surveillance. To complicate the development of an effective vaccine, the virus envelope is able to hide receptor site to antibody that could potentially inhibit its effect (neutralizing antibodies). This explained the inefficiency of antibodies generated by vaccines targeting the glycoprotein 120 (gp120) located on the surface of virus developed in early vaccine trials.4

However, despite these challenges, encouraging progresses in the development of an effective HIV vaccine have been made. The first HIV vaccine trial was opened at the National Institutes of Health (NIH) Clinical Center in 1987, including 138 healthy volunteers. Other large scale trials included participants from North America and The Netherlands (1998), then Africa and Asia (1999).5 Three main approaches have been used in the development of an HIV vaccine: 1) the induction of neutralizing antibodies against HIV using the virus envelope proteins (gp120 or 140), 2) the use of viral vectors to stimulate responses form killer cells (CD8 T-cells or T cell that would recognize antigens on virus surface of the virus-infected cell, binds to it, and kill it), and 3) the optimization of cellular immunity (activation of killer cells) and humoral immunity (production of antibody) with prime-boosts (administration of one type of vaccine, such as a live-vector vaccine, followed by or together with a second type of vaccine, usually a recombinant).6 Also, to cope with the genetic variability of the virus, multiple strategies are explored, such as mixing envelope immunogens from several HIV subtypes or clades. Unfortunately, most of the tested vaccine models did not significantly reduce HIV infection in participants, except an envelope-based subunits’ vaccine tested in Thailand which showed significant decline by about 30% in HIV infection in 2009.7 Though modest, the results clearly show that HIV/AIDS is a vaccine preventable disease. More recently in 2012, a Spanish study showed promising results in the development of a therapeutic HIV vaccine effective in reducing the viral load by 90% after 12 weeks of therapy, awkwardly the vaccine lost effectiveness within a year.8 Just a few days ago, the Duke Human Vaccine Institute team published an important study, in which it has been able for the first time to map the co-evolutions of antibodies and virus in an infected individual, whose immune system launched a broad attack against the pathogen, using new technologies. They also identified the viral surface glycoprotein, which initiated the neutralizing antibody development.9

Despite two decades of disappointing results on HIV vaccine research, we now have started to see encouraging advances. For the first time a candidate vaccine was successful in significantly reducing the HIV infection. Furthermore, an important progress has been made very recently in identifying neutralizing antibodies initialization and mapping. The study provides crucial insights for the development of a vaccine that could mimic the actual antibody development and elicit non-strain specific antibodies. Progress towards finding an effective vaccine is slow, but we can optimistically say that the future is promising.



[1] World Health Organization (WHO), Global Health Observatory (GHO). HIV/AIDS, Global situation and trends. 2012.

2 Letvin, Norman L. “Progress and obstacles in the development of an AIDS vaccine.” Nature Reviews Immunology 6.12 (2006): 930-939.

3Letvin NL. Progress Toward an HIV Vaccine. Annu. Rev. Med. 2005. 56:213–23

4Marc GP, OsmanovSK, Kieny MP. “A review of vaccine research and development: the human immunodeficiency virus (HIV).” Vaccine 24.19 (2006): 4062-4081.

5 National Institute of Allergy and Infectious Diseases (NIAID). History of HIV Vaccine Research. 2012.

6 Ross, Anna Laura, et al. “Progress towards development of an HIV vaccine: report of the AIDS Vaccine 2009 Conference.” The Lancet infectious diseases 10.5 (2010): 305-316.

7 Rerks-Ngarm, Supachai, et al. “Vaccination with ALVAC and AIDSVAX to prevent HIV-1 infection in Thailand.” New England Journal of Medicine 361.23 (2009): 2209-2220.

8 García, Felipe, et al. “A Dendritic Cell–Based Vaccine Elicits T Cell Responses Associated with Control of HIV-1 Replication.” Science translational medicine 5.166 (2013): 166ra2-166ra2.

9 Liao HX et al. Co-evolution of a broadly neutralizing HIV-1 antibody and founder virus. Nature 2013. Epub April 3, 2013

Student Guest Post: Arsenic, Benzene, and Now Clostridium? Smokers are Inhaling More Than Just Chemicals in Their Cigarettes

It’s time for this year’s second installment of student guest posts for my class on infectious causes of chronic disease. Second one this round is by Jonathan Yuska. 

If you happen to be one of the 46 million individuals who have not been swayed to quit smoking by the countless anti-cigarette ads in print and on television, here is one more piece of evidence that may have you second thinking that next puff. On top of the more than 3,000 chemicals and heavy metals already identified in ordinary cigarettes1, upwards of a million microorganisms per cigarette have also been found to live and thrive in virtually all cigarettes in the United States2. Microbes such as Bacillus (which is linked to the notorious anthrax disease), Clostridium, and Pseudomonas—to name a few—likely contaminate the tobacco leaves early at the farm level and are able to flourish during curing and manufacturing to be viable in the cigarette at the time of the consumer’s use. While some of the bacteria are capable of causing no more than a stomachache, others (and their respective endotoxins) have been linked to pneumonia and chronic lung inflammation—a widely recognized risk factor for cancer1,2. While cigarette smoking is a well-established cause of cancer in and of itself, the role microorganisms have in the toxicity of cigarette smoke should not go underplayed. With increasing evidence supporting the vast illness causing biodiversity found in cigarettes, hopefully more individuals will be aware of the dangerous contaminants they are welcoming into their bodies and call for greater sanitary measures to be taken to potentially create a less harmful cigarette product.

Approximately 23 different species of bacteria have been found in cigarette tobacco, many of which have been linked to serious illness in humans. For example, Pseudomonas aeruginosawhich is the leading cause of nosocomial pneumonia and often found in soil or sand—was found to be present in nearly all cigarettes tested in a study that looked at the presence of cigarette bacteria in the most commonly smoked brands, like Marlboro2. Another study interested in understanding the cause of severe lung inflammation in United States troops during Operation Iraqi Freedom found eight different species of Bacillus (five of which were never seen before) contaminating the soldier’s cigarettes3. Regardless of the actual bacteria within the cigarettes, the endotoxins derived from the bacteria that remain well after the bacteria have died have been shown to be a powerful inducer of lung inflammation (chronic inflammation is recognized as a powerful risk factor for cancer). It is theorized that the bacteria and their respective endotoxins may have an additive or multiplicative effect with tobacco smoke’s natural ability to cause pulmonary inflammation, though the amount of the effect that can be attributed is still up to debate2.

Research has shown that more than 90 percent of cigarettes are contaminated with some form of bacteria, and these bacteria are believed to originate early in the cigarette manufacturing process1. Similar to other crop cultivation, tobacco is grown in large fields where animal manure is used to provide the nutrients needed for a hearty crop. Some of the bacteria from the manure are believed to adhere to the tobacco leaves during the plant’s development. Curing the tobacco, which is essential in the cigarette manufacturing process to develop an ignitable, flavorful product, further facilitates bacterial growth because it is often done in moist, warm conditions3. Unlike other agriculture crops grown for consumption, tobacco has no regulations associated with its sanitation, and as a result, tobacco products can contain soil residues and insecticides in addition to a vast array of deleterious bacteria. Efforts to sanitize tobacco through an antimicrobial wash have been proven to be effective in reducing contaminants; however, since so little mainstream attention has been given to microbes in cigarettes, no sanitation process is currently being used by the cigarette industry2.

Misperceptions about how much risk the bacteria pose to the smoker is one reason so little attention has been given to microbes in cigarettes.  Some critics believe that bacteria in cigarettes pose no harm because the cigarette flakes are prevented from entering the lungs because of the built-in filter within the cigarette. Some further argue that the viable bacteria found in the tobacco are destroyed or heavily reduced in number by the heat of the cigarette. Though, the validity of these observations are derailed by the fact in the process of transportation, or even minor jostling, tobacco flakes are often seen lying freely on the mouth end of the filter. Thus, loose tobacco on filters could transfer bacteria to the mouths and lungs of smokers before the cigarette is even lit. Additionally, some extremely fine tobacco microparticulates are able to pass through the cigarette filters currently being used and can be inhaled deep into the lungs to cause inflammation2,5. The harsh, high temperature conditions of cigarette smoking also does little in eliminating the bacteria that are able to produce robust heat resistant endospores such as the bacterial species Bacillus and Clostridium1. It is clear that more attention should be given to dismiss the misperceptions of bacterial risk associated with cigarettes so that effective sanitary regulations can be applied to tobacco similar to other widely consumed foodstuffs.

If the more than 3,000 chemicals and heavy metals that have been identified in ordinary cigarettes have not influenced you to quit smoking, hopefully the realization that one cigarette can contain roughly 1,000,000 microorganisms will have you second thinking the habit the next time you light up. Microorganisms that have been linked to serious illness in humans like pneumonia and chronic inflammation are thought to contaminate tobacco leaves early in the manufacturing process, and these organisms thrive and multiply to be viable bacteria in the consumer cigarette. While cigarettes themselves are recognized as a serious cause of ill health, the role microorganisms have in their toxicity should not be underplayed. With a better understanding of the vast bacterial biodiversity within cigarettes, sanitary regulations that eliminate bacterial contamination should be mandated to potentially make a less harmful tobacco product. Though until then, people should recognize the dangerous bacterial contaminants they are welcoming into their bodies every time they light up.


1.   Sapkota, Amy R., Sibel Berger, and Timothy M. Vogel. “Human Pathogens

Abundant in the Bacterial Metagenome of Cigarettes.” National Center for Biotechnology Information. 22 Oct. 2009. U.S. National Library of Medicine. 13 Apr. 2013 <>.

2.  Pauly, J. L., J. D. Waight, and G. M. Paszkiewicz. “Tobacco flakes on cigarette filters

grow bacteria: A potential health risk to the smoker?” Tobacco Control. 18 Oct. 2007. 13 Apr. 2013 <>.

3. Rooney, Alejandro P., James L. Swezey, Donald T. Wicklow, and Matthew J. McAtee.

“Bacterial Species Diversity in Cigarettes Linked to an Investigation of Severe Pneumonitis in U.S. Military Personnel Deployed in Operation Iraqi Freedom.” Current Microbiology 51 (2005): 46-52.

4. “How to Grow Tobacco.” How To Grow Stuff. 23 Nov. 2007. 13 Apr. 2013


5. Pauly, John L., and Geraldine Paszkiewicz. “Cigarette Smoke, Bacteria, Mold,

Microbial Toxins, and Chronic Lung Inflammation.” National Center for Biotechnology Information. 09 July 2011. U.S. National Library of Medicine. 13 Apr. 2013 <>.



Student guest post: The Fallacious Fad of Foregoing Vaccinations

It’s time for this year’s second installment of student guest posts for my class on infectious causes of chronic disease. First one this year is by Dana Lowry.

Humans have a long history of illness and death from infectious diseases. It wasn’t until the 1790s that we had a solution. Edward Jenner recognized that milkmaids never contracted smallpox but suffered from a more mild disease, cowpox. Jenner took pus from a cowpox lesion on a milkmaid’s hand and placed it in an incision he made in an eight year-old boy’s arm. He then exposed the boy to smallpox; the boy didn’t contract the disease, proving he was immune. Jenner experimented on several other children, including his own 11-month old son, and his theory of passing on immunity proved to be successful. The Latin term for cow is vacca, which is where Jenner coined the term “vaccine”. Jenner’s discovery eventually led to the eradication of smallpox from the U.S. in 1949 and from the world in 1979. For over a century, vaccines were limited to preventing smallpox but as we know today, vaccines prevent a large number of diseases.

Although many developing countries still suffer from the burden of preventable infectious diseases, the U.S. has greatly increased the life expectancy and quality of life through the use of vaccines. In the 1940s, the U.S. recommended vaccines for diphtheria, pertussis and tetanus; polio was added in the 1950s. In the 1970s, measles, mumps and rubella (MMR) were added to list. Today in the U.S., immunizations are recommended for 17 vaccine-preventable diseases during one’s lifetime and more are available for individuals traveling outside of the U.S. Many of these vaccinations are combined so they can prevent multiple diseases from one series of immunizations. The increase in life expectancy in the 20th century is largely attributable to vaccines. For each birth cohort vaccinated, 33,000 lives are saved, 14 million cases of disease are prevented, healthcare costs are reduced by $9.9 billion and $33.4 billion is saved in indirect costs. The Bill Gates Foundation believes that vaccines are one of the most cost-effective investments in global health, saving about 2.5 million lives each year. One child dies every 20 seconds from vaccine-preventable diseases while tens of thousands of other children suffer from severe illnesses and permanently disabling diseases.

Despite the facts, less and less parents are choosing to vaccinate their children today because of fears that vaccines are unsafe. Much of the controversy started with Dr. Andrew Wakefield, a former British surgeon and medical researcher. Wakefield published a paper in 1998 linking the MMR vaccine to autism and bowel disease. Wakefield’s entire study was found to be fraudulent and the infamous paper was retracted in 2010. But, what got more attention than a retracted science paper was Jenny McCarthy sharing her personal life story of how her son got autism from a vaccine on the Oprah Show. Unfortunately, more moms keep up-to-date with Oprah and popular news rather than science and still do not know the truth behind Wakefield’s falsified study; therefore, the autism myth continues.

Furthermore, parents argue “herd immunity”. If your children are effectively vaccinated then why would I have to worry about mine? First, many vaccine-preventable diseases still exist in other countries and can easily be brought into our country; second, some individuals do not build immunity to the disease even after vaccination. The more and more parents that opt out of vaccinations, the less protection their children have from the rest of the “herd”. Additionally, parents argue that their children should contract diseases “naturally” through the environment to build immunity. Parents don’t fully understand the severity of these diseases because many have been virtually eradicated through the successful use of vaccines. Though some crippling effects of polio still linger, it is rare to come across someone wearing braces or using a wheelchair as a result of a polio infection in the U.S. Many vaccine-preventable diseases can cause death during the initial acute illness and if the individual survives, he or she may be left with chronic effects that last a lifetime. Polio can lead to temporary or permanent paralysis, deformities in the hips, ankles and feet; measles, mumps and varicella can all lead to brain damage and mumps is known to cause deafness; hepatitis B can cause permanent liver damage and even liver cancer. The list of damaging effects goes on and on.

In some areas throughout the U.S., as many as 1 in 20 kindergarteners have not been vaccinated. As the antivaccination fad grows in American so do the infectious disease rates. Measles was said to be eliminated from the U.S. in 2000 but an average of about 60 cases of measles occurs each year, typically from traveling. However, in 2011, there were 17 measles outbreaks in U.S. communities and the number of cases jumped to 222. In 2012, the U.S. had one of the largest pertussis outbreaks in nearly 50 years. Nationwide, over 85,000 vaccine-preventable diseases occur each year. I am not arguing that vaccines have no potential side effects and have never caused adverse effects or even death in children. However, I do think vaccines have done considerably more good than harm. So I urge parents, before deciding to withhold your children from vaccinations, look into the facts and make a decision based on science – not popular news. Although outbreaks of disease have been conquered in the past, many vaccine-preventable diseases remain throughout the world and the U.S. is not immune to future outbreaks.


Temple Grandin is wrong on vaccines and autism

Temple Grandin is undoubtedly one of the most famous women with autism of our time. Trained in animal science, Dr. Grandin is a widely read author and noted speaker on autism. April is National Autism Awareness Month, and Dr. Grandin has a new book out, “The Autistic Brain.” Together, this must have seemed like a good time for the New York Times to interview her. Unfortunately, the interview is superficial and not very illuminating, and what Dr. Grandin does say is disappointing. Her take on vaccines and autism, which apparently is elaborated upon in her new book:

Q: In your new book, “The Autistic Brain,” you seriously entertain possible links between vaccines and autism in children, links that scientists have vehemently dismissed.

A: Well, there’s only one vaccine that could possibly be a problem, and that’s the measles-mumps-rubella vaccine. Now that they’ve changed the vaccine, it has fewer antigens, and that would make it a lot safer. But with the old version of the vaccine, I have not yet come across a study that looked at regressives — when a child had some speech but lost it.

Q: There has been a highly emotional battle between mothers of autistic children and the scientists who dispute their theories.

A: I have talked to maybe five or six of those mothers, and that’s the reason I don’t pooh-pooh it. Those mothers have all described the same things. They all have the vaccine, and then they talk about fevers and the weird wailing that started in just a few days. When I brought this up to an expert and asked, “Have you ever studied the regressive group separately?” I got silence.

This is the problem when scientists speak about areas where they’re not experts. I got a lot of flak for my post to my dad addressing vaccines, with people accusing me of being condescending and underestimating his intelligence, but this shows it’s not an intelligence thing at all. (Plus, my dad is plenty intelligent–otherwise why would I bother to write that for him at all?) Grandin is obviously intelligent. She’s also highly educated. She has a PhD in another field. But she’s not an expert in vaccines, as her comments show, and that’s the problem with scientists who speak outside of their area of expertise. Even the very educated amongst us can’t know everything, and it becomes problematic when we use our reputation as scientists to promote something that we don’t have the background knowledge to really understand.

So, Grandin. First, she’s simply wrong about MMR formulation. Perhaps she’s thinking of the DTP vaccine, which now includes an aceulluar pertussis component (“DTaP” or “TDaP”) and therefore has reduced the amount of antigens in the vaccine (not that “excess” antigens are a problem for our immune system, which deals with literally millions of antigens on a daily basis, but that’s another story).

She’s also wrong about studies on regressives. As a scientist, why doesn’t she do her own literature search, rather than “asking experts” and supposedly getting silence? Because she could find several such studies, like this study in the journal Pediatrics or this one in PLoS ONE, if she simply searched.

Her biggest problem, though, isn’t just failure to represent the scientific literature or to understand the MMR vaccine. It’s her over-reliance on anecdote. Simply by the numbers, this correlation between regression and MMR vaccination (or any vaccination) is completely expected. There are currently about 75 million children in the United States. It’s estimated that anywhere from about 1 in 90 to 1 in 50 kids have some kind of autism spectrum diagnosis. Using the higher numbers for the sake of argument and easier math, that’s about 1.5 million kids, and most are diagnosed between the ages of 1 and 5. The first dose of the MMR vaccine is at ~12-15 months of age–when many parents of children with autism are starting to realize that their kids perhaps aren’t communicating like their peers or showing other characteristics of autism, and may think about getting them evaluated. That’s a window of about 1500 days, in which the majority of those 1.5 million kids receive their diagnosis–so averaging a thousand kids a day. Some of those kids will have just gotten shots, and some will have the reactions Grandin mentions–fevers, crying–by chance alone. Some will also wear mismatched socks that day. Some will eat Cheerios for breakfast. But because these aren’t in the news, moms don’t remember the socks, Cheerios, or a thousand other things that their kid did that day that are just as relevant to developing autism as the vaccines they received.

Correlation does not equal causation, and in this case, many, many studies have *disproven* such a link. Talking to “five or six mothers” does not trump years of scientific data looking at many thousands of kids diagnosed with autism, and it’s unfortunate both that Grandin has promoted this type of thinking, and that the New York Times interviewer considered that newsworthy enough to ask Grandin, out of everything else in her book.

What’s up with H7N9, the new avian influenza?

I have a new article up today at Slate, examining the emergent H7N9 avian influenzas, and a bit of a review of “bird flu” in general:

While we were carefully watching H5N1 in Asia and Europe, another influenza virus—2009 H1N1—appeared seemingly out of nowhere. Ultimately traced back to swine, this virus was easily spread between people, but unlike H5N1, it wasn’t any more deadly than our normal yearly influenza viruses (which, it should be noted, still kill on the order of 36,000 Americans each year). And now, while we’re still working on understanding how H5N1 and H1N1 have jumped between species, yet another influenza type has surfaced: H7N9.

An open letter to my dad on the occasion of his recent anti-vax Facebook postings

Pa and I 3Dear Pa,

I know you care deeply about many issues, especially social justice. You’re tired of wars, you’re ashamed of the attempts to destroy social programs in this country, you hate seeing the unions that helped you as a worker provide for our family get dismantled by wealthy CEOs whose only goal is to make themselves and their cronies more wealthy. These are noble things to believe in, and values that you’ve instilled in your children.

But you probably don’t often consider how you select and digest (and frequently, share on Facebook) the stories that you’ll accept as true. This is called cognitive bias–sorry, that’s a terrible article for a layman, but I’d be happy to discuss next time I’m home. Anyway, the bottom line is that the beliefs you already hold prime you to accept certain types of information, and reject others–and it’s something everyone should be aware of when reading anything on the Internet, especially. You don’t investigate how the authors of articles and videos you read and view came to their conclusions, or what data they may have overlooked (I’m being generous here–in most of the things you post, it’s not a matter of “overlooking” contradictory evidence on the case of the authors, it’s flat-out denial that it even exists). And you’re not an expert on health issues like fluoride or vaccines, so I don’t expect you to go back to the journal articles and try to figure out if these people you’re listening to are telling the truth. That’s what I do, but it took years of training to get me to this point, as you probably remember.

You repeatedly caution, “follow the money.” Often this is the case, and no one disagrees that many times people or companies do some nasty shit in the name of profit. However, you have to look at this on a case-by-case basis. Let’s look at vaccines, for instance. Sure, pharmaceutical companies make money off of vaccines. However, this money is a fraction of what they make for drugs that treat chronic conditions or “lifestyle” medicines, like cholesterol meds and Viagra. Indeed, many pharmaceutical companies have gotten out of the vaccine game altogether because it’s not particularly profitable, and because of lawsuits directed against them (which, in most cases, aren’t based in science but on fear and misunderstanding of cause and effect). This leaves us with fewer and fewer options when we need new vaccines quickly, like for the H1N1 pandemic in 2009.

So, we’re agreed that vaccines are potential money-makers for pharmaceutical companies (though, comparatively, not a lot). Let’s look now at those who started the most recent iteration of vaccine panic, including Andrew Wakefield. Wakefield is the British doctor whose study first drew an association between the measles/mumps/rubella (“MMR”) vaccine and autism. Except, first of all, it really didn’t if you look at the original article. And, you might note that article has a big “RETRACTED” notice at the top. This means that the journal took away its support of the paper–it shows that it never should have been published. That’s because, for that study and several others, Wakefield lied about data, unethically recruited test subjects, and/or just outright made shit up. Why might he do this? Well, a British lawyer had paid him to find evidence of this connection between MMR and autism, so that the lawyer could sue on behalf of the parents. Oh, and did I mention that Wakefield stood to make money for a replacement for the MMR vaccine as well? Follow the money indeed–though in this case, it didn’t lead to the pharmaceutical companies. Wakefield was tried in England and stripped of his medical license, but has since moved to the United States and still spreads misinformation about vaccines.

What about other anti-vaccine players? Jenny McCarthy has made millions selling books about how she “cured” her son Evan of his autism. Joseph Mercola makes millions selling dietary supplements (untested and largely unregulated, by the way), and lives in a two million dollar mansion. I know you’ve criticized creationists; well, these people are the creationists of the medical field. They distort, they cherry-pick their evidence, and they cause the public to lose confidence in credentialed scientists because of their writings. Credentialed scientists like myself, who carry out the vast majority of this research but certainly don’t live in million-dollar homes.

And you’re helping the Mercolas of the world–every time you post something like your “Italian court rules MMR vaccine causes autism” picture. Guess what “evidence” that court used? Andrew Wakefield’s discredited study. In science, this is an error even a first-year PhD student would be embarrassed to make. Not surprisingly, the decision is being appealed. But in the meantime, every parent who (wrongly and unscientifically) believes that vaccines caused their child’s autism is being buoyed by this court, whose decision is being trumpeted by people like Mercola and Mike Adams at Natural News (another supplement-pusher like Mercola, with no medical expertise or training). Every time someone buys into their anti-vaccine line and chooses to buy their supplements instead of vaccinating their child, it puts other children in danger. And you’re helping them.

Know the results of this vaccine backlash? Research dollars are diverted away from real causes of autism and other conditions. And kids are dying. Just in the U.S., there have been more than 1000 vaccine-preventable deaths in the last 6 years, and over 100,000 vaccine-preventable illnesses. Freaking whooping cough has made a huge comeback in the U.S. A big reason for the resurgence of these diseases is because anti-vaccine myths and scares spread so easily between acquaintances–in person, and on social media; scares that you’re now perpetuating with your own posts. Sure, it’s a free country and you have every right to share these pictures and memes, but have you thought about the possible harm it might do to others when you click “share”?

I know how crazy it drives you when Republican politicians (and friends and relatives) post pictures and stories that are flat-out wrong, about the deficit, the economy, “Obamacare,” and more. It makes you nuts how uncritically they quote Fox News. They don’t examine their own biases; they don’t stop and think why they accept that Obama is the anti-Christ and that everything associated with him is evil, even if the facts clearly contradict their belief. Sure, they may know a lot, but it’s all from the same sources and it reinforces their pre-existing belief that Obama is Satan. Here’s the kicker: you’re doing the same thing. Yes, I know you’ve watched a lot of YouTube videos on vaccines, and fluoride, and other health issues, but the ones you watch–and accept–are the ones that already appeal to the beliefs you’ve accepted. This isn’t how science works, or how evidence is fairly weighed. I know this can get messy, because again, you’re not one of those trained scientists and you don’t know how to navigate the literature and determine which studies are well-conducted and which ones are crap. So sometimes, you have to accept that there are people out there who have taken the time to do this in an unbiased fashion, and decide to trust them (y’know, people like your daughter, perhaps? Or thousands of other scientists and journalists who have studied these fields for many, many years?), and look skeptically upon people like Mercola et. al. (Follow the money!)

I will be sending along some books I hope you’ll read with an open mind: The Panic Virus by Seth Mnookin, and Deadly Choices by Paul Offit. Both come into this from different backgrounds–Mnookin is a journalist and new parent who was investigating vaccines, while Offit is a research scientist like myself who has worked in vaccines and infectious diseases his whole life. Both come to the same conclusions: vaccines are safe, and critical for public health. And before you google Offit and find that he holds a vaccine patent, ask yourself–if I were to work on a vaccine at some point in my career, would you dismiss my authority and expertise for that reason? Or would you be willing to look at the science behind it before making a judgement?

Next discussion: the Illuminati. Baby steps.




Like this? Find me on Facebook and Twitter!