Starting in 1946, anecdotal cases dribbled in that seemed to link encephalopathy in babies with the whole-cell vaccine
. But a 1983 analysis of 33 cases found no connection.
Surprisingly, the whole-cell vaccine
offered no better than 48 percent protection.
However, baboons that received the acellular vaccine took twice as long to clear the organism from their systems as those that had received the whole-cell vaccine
Others have proposed that the pre- versus post-vaccination era population changes may have been driven by selective pressure of whole-cell vaccines
; the divergence in our study is consistent with this proposal (9-11).
In another Kaiser Permanente study that zeroed in on the transition period between the use of whole-cell pertussis vaccine and DTaP, patients who contracted polymerase chain reaction-confirmed pertussis did so an average of 14.7 years after receiving their last dose in the series if they received one or more doses of whole-cell vaccine
compared with a mere 5.6 years after the last dose if they got the all-DTaP series.
The whole-cell vaccine
for pertussis is protective only against clinical disease, not against infection (15-17).
A dose of DTaP may be given as the fifth dose in the series for children aged 4-6 years who have received either all four prior doses as whole-cell vaccine
or three doses of whole-cell DTP plus dose of DTaP; this fifth doses should be given before the child enters kindergarten or elementary school.
"The durability of protection with the acellular vaccine is not as good as with the whole cell vaccine, but the problem with the whole-cell vaccine
was that it was quite reactive," causing local reactions and fevers, she said in an interview.
Since vaccination with the Dutch whole-cell vaccine
only induces low levels of IgG against pertussis toxin (IgG-PT) and no IgA against B.
Subunit vaccines, like inactivated whole-cell vaccines
, do not contain live components of the pathogen.
The use of whole-cell vaccines
in humans could be inhibited by bacterial components that probably cause undesirable responses (13).
The baboons that received whole-cell vaccines
cleared the bacteria within three weeks, the study found.