To Vaccinate or Not?
This is a very complicated question. There are so many benefits of vaccination that it’s difficult to support not vaccinating a child.
In fact, based on research conducted in 2013, the partial effectiveness of the current Pertussis vaccine may result in vaccinated individuals acting as carriers, thereby spreading the disease further than it normally would. In other words, instead of high levels of vaccination eliminating Pertussis, it may actually help perpetuate the disease.
This is not the first study to make such a claim. Back in 2000, another study had already come to the same conclusion, after studying vaccinated children in two daycare centers as well as their family members. In this case, many of the tested individuals had clear markers of recent infection but had not shown any of the symptoms.
There still seems to be very little data about the percentage of infections that are asymptomatic. However, at least one study has attempted to find the percentage of asymptomatic carriers in a population. An analysis of 629 children in China, aged 7 – 15 were tested for Pertussis. Of those, 4.8% were asymptomatic but tested positive using the PCR test. What does that mean for the United States? Well, it’s hard to say since we don’t know how many total infected there were in the study, but assuming even 1/10th the fraction of asymptomatic carriers in the United States, among the same age group, we’re talking roughly 150,000. As a comparison, there were less than 50,000 reported cases of Pertussis during the 2012 outbreak: the largest in half a century. This would indicate that there are far more carriers than there are symptomatic individuals. (Zhang Q. et al. 2014)
There is yet another factor which I originally failed to take into account when writing this article, partially because the risk is not mentioned in either study on the topic of partial immunity. Because these people have an active infection, they are not just carriers. They are incubators. They give a favorable environment for the disease to mutate and become a potentially more dangerous threat. If you are interested in an estimate of the number of asymptomatic carriers in the United States, you can find one at Spiritual Anthropologist.
The fact that vaccinated individuals can be carriers brings me to another point of discussion. Vaccines can give us a false sense of security. Not only may we actually be sick when we don’t show symptoms, we may think that we’re immune when we are not. How does this potentially impact the spread of disease? There’s a number called the basic reproduction number: also known as r-zero or r-naught. This is the number of secondary infections a diseased individual is likely to produce. A value greater than 1 will result in a spread of infection while a value less than 1 will mean that the disease will die off on its own. One of the factors which impacts the base reproduction number is how likely an infected person is likely to come into contact with someone else. If you have a false sense of security due to vaccinations, the rate will likely be higher due to a decrease in risk aversion.
In order to reduce the risks associated with this threat, it is important that people in high risk situations be tested for infection even if they do not show symptoms. If you are likely to have a lot of contact with a young child, you should definitely get yourself tested. People should also be properly informed regarding the effectiveness of a vaccine and be told that being vaccinated does not guarantee that they are immune.
There is evidence that diseases are becoming resistant to vaccines, much the same way bacterial diseases have become resistant to many forms of antibiotics. (CIDRAP)
When the medical community realized the threat of “superbug” bacteria, they reevaluated the near ubiquitous use of antibiotics. Now that we are starting to see a similar kind of resistance emerge with “superbugs” in regard to vaccinations, perhaps it is time to reconsider whether or not we are over vaccinating.
Some have argued that viruses do not gain resistance to vaccines because it is not the vaccine which fights off the infection, but rather it is the immune system which has been trained by the vaccine. However, the point is that a vaccine, which was once effective at providing immunity is no longer so, and therefore the disease has resisted the vaccine. Note that resistance is far more likely in bacterial diseases than viral diseases because bacteria generally evolve more quickly than viruses do. However, it is not unreasonable to assume that vaccine resistant viruses will evolve, and perhaps have already evolved, as a result of overvaccination.
Due Diligence of Health Organizations
The real issue however, is that the CDC and other health organizations are not doing their due diligence with determining when vaccination is worth while or not. This depends on many factors. It requires taking into account the risks associated with the vaccination, both short term and long term as well as the risks associated with not getting vaccinated, vaccine effectiveness, and how quickly immunity wanes. We still vaccinate against diseases which are very rare in this country. It may be worthwhile to consider vaccinating only high risk individuals such as those who will be traveling to countries where the disease is prevalent.
Considering the lack of interest the CDC has in actually figuring out these factors, I’ve started drafting ideas for two studies of my own. If Politicoid ever creates a full research offshoot, they will be on the top of my list. You can read about both potential studies here.
In addition, above all else, we need open dialog. I have seen far too much hateful rhetoric spewed on the issue, especially, quite frankly, from “pro-vaxxers”. I’ve seen it as horrible as suggesting that the only way the “anti-vaxxers” are going to get it, is when their kid dies. This is not how we should be discussing such an important and complicated issue.
For Future Discussion
1. Modeling B. pertussis infections: creation of a model which includes waning immunity and infectious asymptomatic carriers.
2. Reduced efficacy of combined vaccinations: http://iai.asm.org/content/66/5/2093.short
1. What Your Doctor May Not Tell You About(TM) Children’s Vaccinations (Amazon.com)
2. Relative trends in hospitalizations and mortality among infants by the number of vaccine doses and age, based on the Vaccine Adverse Event Reporting System (VAERS), 1990–2010.
3. June 10th report by the California Department of Public Health
4. Researchers find first US evidence of vaccine-resistant pertussis
5. Acellular pertussis vaccines protect against disease but fail to prevent infection and transmission in a nonhuman primate model
6. Pertussis Infection in Fully Vaccinated Children in Day-Care Centers, Israel