By Dr. Alex B. Berezow
It’s been a tough year for public health. The U.S. is facing a particularly harsh influenza season, but this virus represents only one problematic pathogen.
Another is the bacterium Bordetella pertussis, the causative agent of pertussis (whooping cough). In December, Vermont declared a pertussis epidemic. Last April, so did Washington state.
Both of these infectious diseases have vaccines that can help keep them in check. However, as I discuss in my new book, Science Left Behind, myths surrounding vaccines live on to this day – like zombies that just refuse to die – preventing otherwise responsible people from getting vaccinated.
The influenza vaccine is hounded by the myth that it will give people the flu. Just recently, this myth was repeated on the popular Seattle radio program The Ron & Don Show (the myth was stated by Ron and, thankfully, debunked by Don). With the injectable vaccine, this is biologically impossible because it uses dead viruses; with the nasal spray, mild symptoms may develop because it uses weakened (but live) viruses.
Yet, the myth persists, probably due to two major misunderstandings. First, the word “flu” is used colloquially to refer to anything from a bad cold to food poisoning (often called “stomach flu” or “24-hour flu”). But the influenza virus does not cause these maladies. Thus, it is possible to receive the influenza vaccine, yet still get stricken by any of several different microbes that cause the common cold or food poisoning.
Second, the influenza vaccine isn’t perfect. The CDC estimates this year’s concoction to be 62 percent effective. That is because multiple influenza strains circulate in the population, but the vaccine only covers three of them – picked in advance by epidemiologists who predict which strains will pose the biggest threat each season. Additionally, your body needs about two weeks to mount an immune response to the vaccine, meaning you are vulnerable to infection during that time period.
The pertussis vaccine is hobbled by what, in retrospect, may have been a poor decision about 20 years ago. The old vaccine (DTwP) used whole-cell pertussis. It could certainly cause a fever, but there were also unsubstantiated claims that it caused neurological damage. Because of that, a new acellular pertussis (DTaP) vaccine was created.
The problem, though, is that current evidence strongly indicates that the new pertussis vaccine does not work as well as the old vaccine. Specifically, the new vaccine does not provide as long lasting immunity. Therefore, the combination of children who receive a less effective vaccine and an adult population who often neglects to get their pertussis booster shot (Tdap) is probably driving the uptick in pertussis cases.
Is there any chance that public health officials will switch back to the old vaccine? Probably not. In an e-mail, University of Washington epidemiologist Jeff Duchin wrote, “Returning to the [DTwP] vaccine that causes more side effects would not be successful if it were not acceptable to the public.”
Considering that a substantial number of people still believe vaccines cause autism, it is difficult to imagine ever switching back.
But, a thoughtful, scientifically minded public should ponder that possibility. It may very well be that the risk of using the new, less effective vaccine outweighs the risk of side effects from the old, more effective vaccine. In other words, we must decide if we want more fevers or more cases of pertussis.
In the meantime, please do your civic duty and go get your flu shot.
Dr. Alex B. Berezow is editor of RealClearScience and co-author of Science Left Behind. Berezow holds a Ph.D. in microbiology and lives in the Seattle area.
