ROCKVILLE, Md. - In many ways anticipation of the arrival of the first pneumococcal conjugate vaccine was like a gestational period for first time parents.
From priority review to licensure nine months later by the Food and Drug Administration (FDA), the seven-valent pneumococcal conjugate vaccine (Prevnar, Wyeth Lederle) grew from infancy to a distribution 7 million doses strong.
"The history of vaccine introductions has been pretty dramatic. From the early days of smallpox eradication, polio elimination and control of diseases like pertussis and diphtheria," said Peter Paradiso, PhD, vice president of scientific affairs and research strategy, Wyeth Lederle Vaccines.
"We saw it again in the early '90s with the introduction of the Haemophilus influenzae type b vaccine; a dramatic elimination of a serious childhood disease. I think what we'll see with the pneumococcal conjugate vaccine is once again the power of vaccination - the power of prevention."
Now in post-licensure studies, researchers are looking at surveillance issues, such as serotype replacement and reduction in disease. Data on those studies are not yet available.
The current buzz revolves around the next generation of pneumococcal vaccines, including phase 3 trials of the nine-valent pneumococcal vaccine (Wyeth Lederle) with serotypes 1 and 5 added, as well as an 11-valent pneumococcal conjugate vaccine (F3bis, Aventis Pasteur). The latter, also currently in clinical trials, consists of 11 types of pneumococcal polysaccharides: serotypes 1, 3, 4, 5, 7F, 14 and 19 are conjugated to tetanus or diphtheria toxoids, and 6B, 9V, 18C and 23F are conjugated to both carriers.
Torn by semantics, financial implications and questions of race-based recommendations, members of the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) voted in February on vaccination guidelines including the immunization of the birth cohort for infants up to 23 months; immunization of chronically ill at-risk children ages 24 to 59 months; and consideration for immunization of children ages 24 to 59 months who are black or Native American, in group child care, are socially or economically disadvantaged or those who had frequent or complicated acute OM within the past year.
Recently the ACIP added the pneumococcal conjugate vaccine to the Recommended Childhood Immunization Schedule for January through December 2001.
Vaccinations are administered at 2, 4, 6 and 12 to 15 months. At a price of $58 per dose, the four-dose series costs $232 and approximately doubles the current cost for childhood vaccinations. The vaccine is covered for all children up to 59 months of age under the federally funded Vaccines for Children program, according to Paradiso.
"This is a new generation of vaccine," said Paradiso. "The price reflected that.
"I think that price will be part of the discussion from now forward for all new vaccine introductions," he added.
In pediatrician's offices across the country, as well as in the pages of Infectious Diseases in Children, OM and antibiotics are topics of intense interest.
Widespread use of a pneumococcal conjugate vaccine may precipitate better control of antibiotic treatment worldwide, according to Ron Dagan, MD, professor of pediatrics and infectious diseases, Ben-Gurion University in Beer Sheva, Israel, and editorial board member of Infectious Diseases in Children.
The seven-valent vaccine contains the most common pneumococcal strains, accounting for 80% of invasive disease in infants; it also contains the five most common antibiotic-resistant pneumococci, serotypes 6B, 9V, 14, 19F and 23F.
Wyeth Lederle has also taken steps toward gaining approval for a new indication for the vaccine. "We're working to get otitis media (OM) as an indication for the vaccine. That's been filed with the FDA and is being reviewed," said Paradiso.
The vaccine does appear to reduce some OM incidence, especially in children with frequent bouts of disease.
For more information:
- Dagan R. Conjugate vaccines: Potential impact on antibiotic use. Presented at the Impact of Conjugate Vaccines on Pediatric Disease symposium at the 40th Interscience Conference on Antimicrobial Agents and Chemotherapy. Sept. 17-20, 2000. Toronto.
- Black S, et al. Efficacy, safety and immunogenicity of heptavalent pneumococcal conjugate vaccine in children. Pediatr Infect Dis J. 2000;19:187-195.
- Jonsdottir I. Pneumococcal conjugate vaccine induces protective immunity in toddlers. Session 6. Presented at the 40th Interscience Conference on Antimicrobial Agents and Chemotherapy. Sept. 17-20, 2000. Toronto.
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