A frequent anti-vax talking point centers on vaccine shedding. Like much of the movement, it turns a kernel of truth into a bushel of baloney.

While shedding can occur with some vaccines, there is danger in only very specific cases, cases in which the danger can be eliminated with simple precautions. Anti-vaxxers transform this into the notion that all vaccinated persons are potentially lethal to any unvaccinated persons they come into contact with.

There are three major problems with this thinking. First, it asserts that vaccinations cause and spread disease without explaining how those diseases could have existed before the vaccines did. Second, an anti-vaxxer should consider this inconsequential since they insist that the likes of measles, polio, and swine flu are nothing to worry about, and perhaps even to be celebrated.

Most importantly, except in rare, specific instances, vaccinated persons cannot infect someone who is dutifully repelling rubella with homeopathic eucalyptus drops. For starters, to be impacting someone else, the vaccinated would need to be shedding an infectious agent, specifically a live virus. They could not be a danger to anyone after being given an inactivated vaccine like polio, hepatitis A, or Whooping Cough.

Such vax facts weren’t about to stand in the way of blogger Cynthia Janak, who warned that selfish pro-vaxxers could spread Whooping Cough to the unvaccinated. Which raises the question of why only the unvaccinated would be at risk from shedding. Anti-vaxxers insist that vaccines aren’t effective and also insist that vaccine shedding spreads disease to nearby persons. If all this was true, the vaccinated should also be infecting others who have been immunized. Further, the one doing the shedding should also be getting sick, as they are hosting the virus and are the one closest to the virus when it sheds. And if shedding claims were true, younger siblings of freshly-vaccinated toddlers should be dying at a rate of hundreds per day.

The inexhaustible Janak has written hundreds of posts promoting anti-vax beliefs and she claims to have done thousands of hours of research. Yet none of those hours were dedicated to learning the relatively simple concept that the Diphtheria-Tetanus-Pertussis vaccine contains an inactivated toxin and not a live virus. Also, please note that when an anti-vaxxer references their “research,” they almost invariably mean Internet surfing and exchanging anecdotes with the likeminded. They do not mean conducting laboratory experiments, running controlled tests, overseeing double blind studies, or publishing in peer-reviewed journals.

That is why, for all this alleged research, Janak wrote a column entitled, “Will the vaccinated infect the unvaccinated? That is the question with Whooping cough.” In it, she writes, “Vaccine shedding is the transmission of the virus from a vaccinated person to an unvaccinated person. All these parents and child care workers are going to get the vaccine and then have the potential to infect the unvaccinated child.” That the children could be infected due to their unvaccinated nature never occurs to her.

Again, for it to even be possible to impact someone else, a live virus must be shed, and this does not occur with the Whooping Cough vaccine. Shedding can only happen with live virus vaccines, such as MMR, varicella, and rotavirus. And when this does occur, shedding is not synonymous with transmission. As the name suggests, that would require something being transmitted from one organism to another, and only the tiniest percentage of shedding instances lead to transmission.

Viral shedding is recognized as a reality by pro-vaxxers, and doctors stress that caution should be exercised when the recently vaccinated will be around newborns or persons immunocompromised or pregnant. Special care should be taken to ensure that vulnerable individuals avoid coming into contact with the excrement of the recently immunized persons for two weeks. To recap, in order for shedding to be a danger, it must involve a live virus and the exposed person must be in one of three categories and must come into contact with the immunized individual’s stool within a fortnight. That it needs to occur in these very specific, avoidable circumstances is consistent with the rarity of vaccine shedding being harmful.   

One final crazy kicker to this. Janak wrote a column about the danger that persons vaccinated for chickenpox pose to the unvaccinated, warning the latter could catch the disease through shedding. She later extolled the virtues of intentionally exposing children to the disease at pox parties. So she expresses outrage that adults who refuse the vaccine might catch the disease, then celebrates purposefully passing that vaccine-preventable disease onto children and infecting them with a condition that brings a 1 in 60,000 chance of death.