Lies About the Pertussis Vaccine

Graph of the incidence of pertussis. 1922 to 2014

Dr. S.H.* is a med­ical doc­tor, but she is spread­ing dan­ger­ous false mes­sages about vac­cines. In par­tic­u­lar, she has been mis­rep­re­sent­ing the results of a study of the vac­cines against per­tus­sis (whoop­ing cough). Anti­vac­ci­na­tion activists like to cite sci­en­tif­ic research. They want to cre­ate the impres­sion that they have done their home­work, and that their opin­ions are sci­en­tif­i­cal­ly sound. They often claim to be doing “research.” Yet when you look them up in, you find that their pub­li­ca­tion record is thin or nonex­is­tent. Although the anti­vac­ci­na­tion zealots some­times read med­ical jour­nal arti­cles, they typ­i­cal­ly mis­un­der­stand the arti­cles that they dis­cuss. As some­one who has edit­ed text­books and med­ical jour­nals for a liv­ing for more than 25 years, I find their mis­un­der­stand­ings to be irri­tat­ing. Their work is so full of obvi­ous errors of fact and errors in rea­son­ing that it would nev­er have passed muster at any of the sci­en­tif­ic pub­lish­ing com­pa­nies for which I have worked. And yet their work is get­ting plen­ty of hits on the Inter­net!

Dr. H.’s basic argu­ment is this: She thinks that it would be bet­ter for your baby to catch whoop­ing cough, which is a hor­ri­ble and some­times dead­ly dis­ease, than to be vac­ci­nat­ed against whoop­ing cough. This is what whoop­ing cough is like:

Some­times, per­tus­sis is even worse than this. Some new­borns are not strong enough to cough like this. Instead, they sim­ply stop breath­ing and die, with­out warn­ing.

Dr. H. claims that this study by War­fel and cowork­ers shows that hav­ing a nat­ur­al Bor­de­tel­la per­tus­sis infec­tion would be bet­ter than vac­ci­na­tion for pro­mot­ing herd immu­ni­ty. This idea is total non­sense. Whoop­ing cough was once com­mon. It is now rare, thanks to vac­ci­na­tion. Hav­ing more nat­ur­al cas­es of Bor­de­tel­la per­tus­sis infec­tion among the pop­u­la­tion would lead to more ill­ness and more deaths. Bet­ter vac­ci­na­tion cov­er­age leads to less ill­ness and few­er deaths.


The first vac­cine against Bor­de­tel­la per­tus­sis was intro­duced in 1940. At the time, rough­ly 6,000 Amer­i­cans per year were dying of whoop­ing cough. Rough­ly 95% of the dead were chil­dren. Thanks to the vac­ci­na­tion, the death rate dropped sharply. How­ev­er, we are still see­ing occa­sion­al cas­es of whoop­ing cough, even in high­ly vac­ci­nat­ed pop­u­la­tions. Even the immu­ni­ty that results from a nat­ur­al infec­tion lasts for only 4 to 20 years. The pro­tec­tion from vac­ci­na­tion lasts for only about 4 to 12 years. That is why doc­tors urge peo­ple to get boost­er shots against per­tus­sis. If you have par­tial immu­ni­ty to per­tus­sis, you might get only a mild case of the snif­fles from a Bor­de­tel­la per­tus­sis infec­tion. Yet you could pass the bac­te­ria on to some­one else, who could get severe­ly ill.

War­fel and cowork­ers want­ed to answer an impor­tant ques­tion: Is the mod­ern acel­lu­lar per­tus­sis vac­cine less effec­tive than the old-fash­ioned whole-cell vac­cine at pre­vent­ing the spread of Bor­de­tel­la per­tus­sis from per­son to per­son? Since it would be unthink­able to expose human beings to live Bor­de­tel­la per­tus­sis, the researchers used baboons as exper­i­men­tal sub­jects. (Of course, many peo­ple have eth­i­cal objec­tions to the use of ani­mals, and espe­cial­ly pri­mates, as research sub­jects.) Like human beings, baboons get a bad cough from a Bor­de­tel­la per­tus­sis infec­tion.

War­fel and cowork­ers found that both the acel­lu­lar vac­cine and the whole-cell vac­cine were effec­tive for their pri­ma­ry pur­pose, which is to pro­tect the vac­ci­nat­ed indi­vid­ual from get­ting sick after expo­sure to Bor­de­tel­la per­tus­sis. How­ev­er, the whole-cell vac­cine gave the baboons a lit­tle help in clear­ing the Bor­de­tel­la per­tus­sis from their upper res­pi­ra­to­ry tract. The acel­lu­lar per­tus­sis vac­cine did not. It took 21 days for the baboons that received the whole-cell vac­cine to clear the Bor­de­tel­la per­tus­sis from their upper res­pi­ra­to­ry tract. It took unvac­ci­nat­ed baboons and baboons that received the acel­lu­lar vac­cine about twice as long to clear the bac­te­ria from their upper res­pi­ra­to­ry tract.

Dr. H. point­ed out that the Bor­de­tel­la per­tus­sis bac­te­ria could not col­o­nize the baboons that were recov­er­ing from a recent Bor­de­tel­la per­tus­sis infec­tion. From that, she con­clud­ed that nat­ur­al infec­tions were bet­ter for pro­mot­ing herd immu­ni­ty. Yet even the immu­ni­ty pro­duced by a nat­ur­al infec­tion declines after a few years. Also, the basic repro­duc­tion num­ber of per­tus­sis is 5.5, which means that in a sus­cep­ti­ble pop­u­la­tion, a sin­gle nat­ur­al case of per­tus­sis would tend to lead to an aver­age of 5.5 new cas­es of per­tus­sis. So if we relied on nat­ur­al immu­ni­ty to solve our per­tus­sis prob­lem, we would have huge epi­demics of per­tus­sis, as opposed to occa­sion­al small out­breaks.

The study by War­fel and cowork­ers was not about whether to vac­ci­nate against per­tus­sis. It was about which vac­cine to use. In the 1990s, Amer­i­cans switched from the whole-cell vac­cine to the acel­lu­lar vac­cine because the whole-cell vac­cine some­times caused chil­dren to spike a fever. This fever could some­times cause a febrile seizure. These seizures were ter­ri­fy­ing to the par­ents, but they do no last­ing harm to the child. Some oth­er coun­tries con­sid­er this risk of fever to be accept­able because the whole-cell vac­cine may be bet­ter for stop­ping the spread of Bor­de­tel­la per­tus­sis.

Bor­de­tel­la per­tus­sis is found only in human beings. Thus, we might be able to dri­ve this germ into extinc­tion through vac­ci­na­tion. Once it is extinct, nobody will need to get a per­tus­sis vac­cine. Yet to dri­ve per­tus­sis into extinc­tion, we will need a bet­ter vac­cine, one that pro­vides longer-last­ing pro­tec­tion against the car­ri­er state, not just against clin­i­cal dis­ease. In the mean­time, we need for peo­ple to get their chil­dren vac­ci­nat­ed and to keep up to date with their per­tus­sis boost­ers!


*I do not use her real name because I do not like to give peo­ple unde­served atten­tion. I explain my rea­son­ing in these two books: