NEW YORK (Reuters Health) - In children with asthma and recurrent respiratory tract infections, nasal spray flu vaccine (sometimes called live attenuated influenza virus vaccine) is well tolerated and more effective than inactivated influenza virus vaccine given as a shot, according to the results of two studies.
In the first study, Dr. William C. Gruber, from Wyeth Research in Pearl River, New York, and colleagues assessed the outcomes of 2220 children with asthma, who were between 6 and 17 years old. They were randomized to receive the live attenuated nasal spray flu vaccine or the inactivated flu vaccine shot during the 2002-2003 influenza season.
The influenza rate in the nasal spray flu vaccine group was 4.1 percent, significantly lower than the 6.2 percent rate noted in the group that got the flu shot. Thus, the nasal spray had a greater relative efficacy of 34.7 percent. The occurrence of asthma flare-ups and other asthma-related episodes did not differ significantly between the two vaccine groups.
Nasal congestion and runny nose were more common with the nasal spray flu vaccine than with injected flu vaccine -- 66.2 percent versus 52.5 percent. Injection site reactions were noted in 70 percent of those who got the inactivated flu jab.
In the second study, the researchers evaluated the efficacy of the nasal spray flu vaccine and the flu shot in 2187 younger children (between 6 and 71 months) with a history of recurrent respiratory tract infections.
Compared with the flu shot, the nasal spray flu vaccine was associated with fewer cases of influenza due to viral strains similar to the vaccine, the report indicates. Moreover, respiratory tract-related health care visits were fewer in the nasal spray flu vaccine group and these children also missed fewer days of school or day care.
The nasal spray flu vaccine was more often associated with nasal symptoms, ear infection, and decreased appetite than the flu shot, the authors note, but the frequency of wheezing was similar in both vaccine groups.
Taken together, the findings from the two studies favor the use of nasal spray flu vaccine over the flu shot in children with asthma or recurrent respiratory tract infections, Gruber's team concludes.
SOURCE: The Pediatric Infectious Disease Journal, October 2006.