Swine flu vaccine given out to 73 children at Schenectady County health clinics last month may not be strong enough to ward off the H1N1 virus.
Spokesman Joe McQueen said Schenectady County received 500 doses of a vaccine that was among 800,000 ordered recalled by the federal Centers for Disease Control and Prevention. He said the shots were administered to children ages 6 months to nearly 3 years, but pose no danger to the youngsters.
“It’s not a safety recall,” he said Tuesday. “[The shot] is not as potent as it was meant to be.”
Pre-filled syringes of the vaccine were produced by Sanofi Pasteur, the vaccines division of France-based Sanofi-Aventis Group, but tests later determined the potency of the vaccine had dropped below the manufacturer’s specifications. Officials from the state Department of Health were notified about the recall Monday and have determined 251 providers around New York received the weak vaccine.
Dr. Anne Schuchat, a CDC flu expert, stressed that parents don’t need to do anything or to worry if their child got one — or even two — shots of the recalled vaccine. It is safe and effective, she said.
The issue is the vaccine’s strength. The vaccine all tested fine when it was shipped out earlier this fall. But last week, testing of one lot showed that the potency had fallen about 12 percent below the government standard.
The company found three other lots with diminished strength and did a voluntary recall, asking doctors to return any unused doses.
Why the potency dropped isn’t clear.
“That’s the $64,000 question,” said Len Lavenda, a Sanofi Pasteur spokesman.
Young children are supposed to get two doses, spaced about a month apart. Health officials don’t think children need to get vaccinated again, even if they got two doses from the recalled lots, said Schuchat.
Officials with the Food and Drug Administration, the CDC and the company all said they believe the strength of the recalled doses is still high enough to protect children against the virus. No potency problem has been detected in the same vaccine packaged in other types of syringes or vials, Lavenda said.
Experts have a theory that the problem is specific to the children’s pre-filled syringes. For some reason, the antigen — the key vaccine ingredient — may be sticking to the walls of those syringes, said Dr. Jesse Goodman, the FDA’s deputy commissioner for science and public health.
Another manufacturer, Novartis, in February recalled five lots of seasonal flu vaccine packed in pre-filled syringes under similar circumstances.
Sanofi Pasteur bills itself as the No. 1 manufacturer of flu vaccines in the world. It makes flu vaccine at sites in France and in Pennsylvania.
Swine flu was first identified in April. During the first seven months of the pandemic, it has sickened about 50 million Americans and killed about 10,000, according to CDC estimates.
McQueen said the children that received the shots are generally scheduled to receive another this month anyway. He said their families will be contacted and urged to get a booster shot.
Health department spokeswoman Claire Pospisil said the recalled vaccine is no cause for alarm. She said parents of children who received vaccine from the recalled lots do not need to take any action, other than to complete the two-dose immunization series.