A recent Columbian editorial (“Anti-vax falsehoods fuel outbreaks of disease, In Our View, June 18) discussed vaccine hesitancy in general and the DTP (Diphtheria/Tetanus/Pertussis) in particular as part of the reason for the recent uptick in cases of whooping cough in Clark County and elsewhere.
However, a study in Canada indicates that the DTP vaccine effectiveness actually wanes pretty dramatically over time. “Our analysis, which is stratified by time since last vaccination and adjusted for age, suggests that the low estimates of vaccine effectiveness beyond 4 years from last vaccination are attributable to waning immunity” and “beyond 7 years since the last vaccination there is minimal protective effect of the vaccine.”
The same study also found different results of effectiveness on the types of vaccines used — acellular (worst results) vs. whole cell (best results). The CDC website says “the acellular pertussis vaccines now used in the United States do not protect for as long as the prior whole cell pertussis vaccine.”
It is important to look at the details to understand the true effectiveness of a particular vaccine and not just assume that following the current CDC recommendations will ensure no infection.
