CHICAGO, Dec 21 - The Australian vaccine manufacturer CSL Ltd said Monday its pandemic H1N1 vaccine for swine flu delivered a strong immune response after a single dose for children as young as 6 months .
Public health authorities recommend that children receive two shots of the swine flu for total protection, but the CSL vaccine showed a strong reaction with a single shot.
"This is good news that children, including very young children, responded with a single dose. It really is as good as we could hope, "said Dr. Anthony Fiore of the U. S. Centers for Disease Control and Prevention, who wrote a commentary accompanying the study in the Journal of American Medical Association.
The results indicate a single shot of vaccine to protect infants and children, a group that was particularly vulnerable to the pandemic flu H1N1.
In the study, a single dose of 15 micrograms produced protective antibody levels in 92 percent of children aged 6 to 36 months, and 92.9 percent of children ages 3 to 9
After a second dose was 100 percent of children in both age groups protected. No serious safety problems were reported with the vaccine.
"The most important conclusion is that the exact dose of vaccine against swine flu seems to be very effective in children as young as six months," Dr. Michael Greenberg, director of clinical development of CSL's vaccine, has said in a telephone interview.
"Although we have seen similar reactions in adults, the fact that we were able to obtain a protective antibodies in most children, even after one dose of vaccine is what makes these unique results."
Currently, all H1N1 vaccines in the United States for children aged 3 and over is given in a dose of 15 micrograms, while children 6 months to three years are 7.5 microgram dose of the vaccine, Fiore said in a telephone interview.
The study of CSL has also tested a higher dose of 15 micrograms in children and found no significant side effects.
"They were testing a double dose of the vaccine in young children - more than currently approved," said Fiore.
Fiore said it is not clear why children in the study as good of a single dose of vaccine. He said it may be inadvertent, as some had been exposed to swine flu and their immune systems are already filled, or it may be how they were tested in the laboratory. Or, he said, it may be that the CSL vaccine does a better immune response.
Fiore says that the results do not suggest that any vaccine against swine flu approved for children only require dose. Trials of vaccines against other shows that children should receive two doses for protection.
"There is a vaccine, a one-year study, and is connected with a long experience with small children who have never been vaccinated need two doses," he said.
CDC estimates that the swine flu killed 10,000 Americans, including 1,100 children, and to 200,000 in the hospital since its debut in March.
The U.S. government has struggled to vaccinate 160 million Americans deemed most in need of H1N1 vaccine, but it had 100 million doses of H1N1 vaccine, like last week. CSL has been contracted to deliver 36 million doses of vaccine, and Greenberg said so far it has delivered everything the government asked. GM Hot News
