Kids' Flu Vaccine: Spray May Beat Shot
Experimental Nasal Spray Was More Effective Than Injected Flu Vaccine in Study of Young Kids
May 1, 2006 -- An experimental flufluvaccine given as a nasal spray may be better at preventing flu in young children than flu shots, a new study shows.
The nasal spray is called Cold-Adapted InfluenzaInfluenzaVaccine Trivalent (CAIV-T). It's a new form of FluMist, a nasal spray flu vaccine approved for children and adults aged 5-49 years.
The nasal spray includes live but weakened flu virus. The flu shot contains killed flu virus. Both are made yearly to target flu strains experts predict to be common in that year's flu season.
Saint Louis University's Robert Belshe, MD, and colleagues tested the CAIV-T spray on kids who were at least 6 months old but not yet 5 years old.
"We tested this needle-free vaccine in more than 8,000 children at 249 sites in 16 countries," Belshe says, in a news release from St. Louis University's medical school.
The results were reported in San Francisco, at the Pediatric Academic Societies' annual meeting.
Shot or Spray
Belshe's team randomly assigned the children to get either the CAIV-T nasal spray or an injected flu vaccine before the 2004-2005 flu season. The CDC recommends flu vaccination for all children who are at least 6 months old and have no conditions that rule out use of the vaccine.
The researchers didn't want the vaccine's form to be obvious. Scientists commonly conceal the form of treatment in medical studies. The goal is to overcome any expectations about which form works better.
So Belshe's team gave kids in the CAIV-T group an injection containing no medicine. Children who got their vaccine via injection also got a nasal spray containing no medicine. That way, no one could tell who had gotten CAIV-T and who had gotten the injectable vaccine.
Study's Results
The kids who got their flu vaccine from the nasal spray had 55% fewer confirmed flu cases.
The spray was also "superior" to the flu shot, the researchers write, at protecting against flu strains not covered by the vaccine.
Side effects were generally similar in both groups. Runny noses and nasal congestion were more common with the nasal spray. Injection-site reactions were more common among those who had gotten the flu shots.
Only children were included in the study. So the results don't show if people aged 50 and older (who aren't eligible for the current version of FluMist) might also benefit from the new spray.