A nasal spray appears to be more effective than flu shots in protecting children under 5, according to a major study published today.
Researchers gave either flu shots or MedImmune’s FluMist nasal spray to almost 8,000 young children in 2004 and found that of the nearly 500 children who caught the flu, those given shots caught it twice as often.
The study, published in the New England Journal of Medicine, was funded by MedImmune, which is trying to persuade the Food and Drug Administration to approve FluMist for use by children between ages 1 and 5. Researchers at the St. Louis University medical school say it’s the largest pediatric study conducted comparing flu shots to the spray.
“It’s good news. We need it, we need a new flu vaccine for children,” said Dr. Neal A. Halsey, director of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health. He was not involved in the study.
Dr. Robert B. Belshe, the lead investigator and a professor of medicine and pediatrics at St. Louis University School of Medicine, said the spray works better in children because it’s a weakened version of live flu virus. Injected vaccine is killed virus.
“The live vaccine gives a broader response, better than a flu shot,” Belshe said.
Another advantage, he said, is that while shots stimulate antibodies in the blood, the nasal spray stimulates antibodies in the blood and the nose.
“Shots are good at boosting pre-existing immunity,” he said. “But they don’t work as well where there is no pre-existing immunity.”
The study shows FluMist is safe for children from 1 to 5 with no history of wheezing or asthma, said Belshe. But, he said, there is still a need for a safe vaccine for children under a year old. The study results show that 42 of the infants between 6 to 11 months old were hospitalized within six months of being given the nasal spray, compared with 18 hospitalization cases among infants given shots.
Belshe called the hospitalization rates “puzzling” and said many of the hospitalized children had problems largely unrelated to flu, such as diarrhea and lung infections.