holmesii lacks most of the antigens present in the pertussis
acellular vaccine or the proteins produced differ phenotypically (4).
Would it be effective to use the
acellular vaccine for the first three shots--until the child is 18 months old--and then give the old whole-cell vaccine?
There are two different types of pertussis vaccine, whole cell and
acellular vaccine (1), (4).
The dosage is the same whether the whole cell or
acellular vaccine is used.
In each, the
acellular vaccine seemed to impart protection and had few side effects.
But the limited duration of protection from the
acellular vaccine found in these studies "raises the question of whether routine administration of Tdap in younger children is warranted," the investigators added.
(4) A recent Cochrane review on acellular pertussis vaccines concluded that the
acellular vaccine had fewer adverse effects than the whole-cell version, but did not support any changes in contraindications or precautions.
The
acellular vaccine has purified portions of the bacteria.
Forty-six infants had received no pertussis
acellular vaccine, and 11 had received 1 dose.
pertussis cases, which began in 2005 and then spiked even higher in 2010, implicated the
acellular vaccine as the cause.
Walther says, however, that this change to the so-called
acellular vaccine is not immediately apparent to parents looking for safety information on the Internet.
Additional information about the immunogenicity and safety of a fifth dose following four previous doses of the same
acellular vaccine is being collected and should be available before infants started on this new schedule are aged 4-6 years and require a fifth dose.
In the past 10 years, plasma-derived and yeast-derived vaccines against hepatitis B, an
acellular vaccine against pertussis, and three vaccines against Hemophilus influenzae type b (Hib) have been introduced.
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.
In the Swedish study, infants received a five-component or a two-component
acellular vaccine, the standard whole-cell vaccine, or no vaccine.
