|Prevnar Vaccine Protects Entire Families, Not Just Infants|
But pediatricians are struggling to cope with a limited supply
By Randy Dotinga
FRIDAY, May 7 (HealthDayNews) -- Vaccinate your child against pneumococcal disease and protect your family as well.
That's the message of a new study suggesting that babies who get vaccinated against the pneumococcal germ are less likely to infect their parents and siblings.
There's a catch, however. The children's vaccine, called Prevnar, is in short supply. So, pediatricians are carefully doling it out until the sole U.S. manufacturer -- Wyeth Vaccines -- can reach full production.
The shortage notwithstanding, the study findings are good news for adults, said study co-author Dr. Henry Shinefield, co-director of the Kaiser Permanente Vaccine Study Center in Oakland, Calif. "Without the possibility of side effects, you get protection," he said.
The vaccine protects against contagious pneumococcal infections, which can cause a variety of diseases from ear and sinus infections to pneumonia, meningitis and blood poisoning. Infants and the elderly are most vulnerable, said Dr. Victor Nizet, an associate professor of pediatrics at the University of California, San Diego.
Prevnar appeared on the market in 2000 (a previous version for adults doesn't work in children) and quickly became accepted by pediatricians. It offers protection against the seven most common pneumococcal strains associated with severe illness, Nizet said, and appears to prevent serious complications and, perhaps, ordinary ear infections.
Doctors typically vaccinate infants at 2, 4 and 6 months of age, with a booster shot between 12 and 15 months of age, Nizet said. The protection lasts at least until age 5, according to Shinefield.
In their new study, funded by Wyeth Vaccines, Kaiser Permanente researchers examined the medical records of 37,868 vaccinated children. The findings were released this week at a Society for Pediatric Research conference in San Francisco.
Cases of serious pneumococcal disease dropped by 64 percent among children aged 5 to 19 years old who lived in the households of those vaccinated; cases fell by 36 percent among adults aged 40 to 59.
"This is a situation where the disease is transmitted from the infant to the adult," Shinefield explained. "Many of the diseases go the other way."
Unlike influenza, which is easily transmitted in public places, pneumococcal disease seems to like to infect people at home, he added: "Each bug is different."
In another finding, the researchers discovered pneumococcal infections that are immune to penicillin dropped from 15 percent of all cases in 2000 to 5 percent in 2003. Apparently, the vaccine is cutting down on the pneumococcal germ's ability to develop immunity to the antibiotic.
"This is a welcome trend that gives doctors more options for effective treatment of both commonplace and serious pneumococcus infections," Nizet said.
But the ongoing shortage of Prevnar could limit the benefits, he warned. Indeed, just 72 percent of infants served by Kaiser Permanente in northern California are being vaccinated, compared to 90 percent in 2001, Shinefield said.
The U.S. Centers for Disease Control and Prevention is recommending that infants only receive two doses -- the first two -- instead of the usual four, to make the vaccine available to more children.
To learn more about pneumococcal disease, visit the National Foundation for Infectious Diseases. The U.S. Centers for Disease Control and Prevention offers information about the Prevnar shortage and new dosage recommendations.
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SOURCES: Victor Nizet, M.D., associate professor, pediatrics, University of California, San Diego; Henry Shinefield, M.D., co-director, Kaiser Permanente Vaccine Study Center, Oakland, Calif.; May 3, 2004, presentation, Society for Pediatric Research conference, San Francisco