Hospitalization Rates Higher in Kids Who Get Flu Shots

May 20 -- TUESDAY, May 19 (HealthDay News) -- Children who get the annual flu vaccine, especially those who have asthma, may be more likely to be hospitalized than children who don't get the shot, a new study shows.

But the researcher noted that the surprise finding probably has more to do with the severity of the underlying illness in children receiving the vaccine than with any deficiency in the vaccine.

"This may not be a reflection of the vaccine but that these patients are the sickest, and their doctors insist they get a vaccination," said study author Dr. Avni Y. Joshi, a fellow at the Mayo Clinic in Rochester, Minn. She is to present her findings Tuesday at the American Thoracic Society's annual meeting, in San Diego.

Other experts came to similar conclusions about the finding.

"I would be very cautious about interpreting this," said Dr. Gurjit Khurana Hershey, director of asthma research and professor of pediatrics at Cincinnati Children's Hospital. "The bottom line is that kids with asthma who get the flu vaccine are probably a different population anyway. They may be the more severely ill children, so it may have very little to do with the vaccine."

The study has too many unknowns and covers too wide an age range over too many flu seasons to indicate any change in recommendations, said Dr. Hank Bernstein, a member of the committee on infectious diseases of the American Academy of Pediatrics and a professor of pediatrics at Dartmouth Medical School.

"We know that the efficacy of the vaccine can be limited in younger children," he said. "The current recommendations are to immunize all children 6 months through 18 years. Household contacts and out-of-home caregivers of all healthy children under 5 years of age, and children with a chronic medical condition that puts them at increased risk of complications from the flu should also get the vaccine every year."

Children aged 2 to 18 years can get either the injected trivalent inactivated influenza vaccine (TIV) or the live attenuated influenza vaccine (LAIV), given in the form of a nasal spray. Children under 2 should get only TIV, he added.