Swine Flu: One Shot is All You Need
Early results from the first trial of a pandemic flu vaccine suggest that just one dose is likely to provide "robust" protection from the new H1N1 strain, also dubbed swine flu, researchers said Thursday.
The study, sponsored by Australia-based CSL Limited, showed that nearly 97% of volunteers given a standard dose of the vaccine produced antibody levels that typically protect against flu infection, giving planners the welcome news that they may need less vaccine to save more lives.
"If those data hold up, it would be a very good result," said William Schaffner of Vanderbilt University in Nashville, president-elect of the National Foundation for Infectious Diseases. "Frankly, I had anticipated it would take two doses" weeks apart.
The pandemic vaccine appears to be as safe as the vaccines made for seasonal flu. No one in the study died, but the study was not big enough and did not last long enough to identify possibly rare side effects, researchers reported online in The New England Journal of Medicine.
"Hopefully, now the regulators can make some decisions on what they want to do with their vaccination program down the road," CSL Biotherapies President Paul Perreault added. CSL has agreed to produce 36 million doses for the USA. The first deliveries are scheduled for mid-October.
Doctors are awaiting the results from additional studies sponsored by four other vaccine manufacturers and the National Institute of Allergy and Infectious Diseases.
The CSL study involved 240 healthy adults ages 18 to 64, divided into two groups. One group was given the standard 15-microgram dose used in seasonal vaccines, and the other received 30 micrograms.
Both single- and double-dose vaccinations appear to be equally protective. The immune response appeared to be consistently potent regardless of the patient's age.
Unlike seasonal flu, which disproportionately affects the very young and the very old, pandemic flu is striking people ages 5 to 24 more frequently.
Meanwhile, Secretary of Health and Human Services Kathleen Sebelius, Centers for Disease Control and Prevention Director Thomas Frieden and a number of infectious disease specialists urged people Thursday not to overlook seasonal flu, which kills at least 36,000 people a year and puts 200,000 more in the hospital.