Acellular Pertrussis Vaccinations in Infancy Provide Protection up to Age 6

[Guest guest]

I wonder if the US will even take a look at this study. A vaccine that is

not necessary would cost the pharmaceutical company's to much $$$. All of you

who know parents that are still vaccinating should let them know about this.

Acellular Pertussis Vaccinations in Infancy Provide Protection up to Age 6

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WESTPORT, CT (Reuters Health) Nov 07 - The protection against pertussis

afforded by three doses of diphtheria-tetanus-acellular pertussis vaccine

(DTaP) administered at 2, 4 and 6 months of age persists through 6 years of

age, Italian investigators report.

Dr. Stefania Salmaso, of the Instituto Superiore di Sanitá in Rome, and

colleagues have prospectively followed children who received vaccinations

between 1992 and 1993. They have previously reported protective efficacy of

84% in the first 2 years of life, which persisted through age 33 months.

As reported in the November issue of Pediatrics, in this third stage of

followup from ages 3 to 6, occurrence of pertussis was monitored until the

end of 1998. Included were 4217 children who had received the Kline

Beecham DTaP vaccine, 4215 who had received vaccine manufactured by

Chiron-Biocine, and 1122 who had been given diphtheria-tetanus vaccines only.

Parents were telephoned monthly and asked about episodes of coughing that

lasted at least 7 days.

Dr. Salmaso's team identified 122 episodes of laboratory-confirmed pertussis,

as well as an additional 163 episodes in which titers of serum IgG against

pertussis toxin or filamentous hemagglutinin were elevated. The efficacy of

the two vaccines was 78% to 81%, based on case definition as

laboratory-confirmed infection with at least 14 days of spasmodic cough or at

least 21 days of any cough.

The Italian researchers found that mean duration of cough among the cases was

47 to 48 days among those who received DTaP vaccines and 70 days for those

who received DT vaccine. " These findings suggest that even 5 years after

primary immunization, most of the 'vaccine failures' show a milder clinical

presentation of pertussis, " they write.

They suggest that, so long as immunity to diphtheria and tetanus is

maintained, the fourth dose of DTaP can be postponed until preschool age if a

child had received three doses in infancy.

Pediatrics 2001;108:e81 [http://www.pediatrics.org/]

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