Inactivated flu vaccine does not appear to be effective in preventing influenza-related hospitalizations in children -- especially if they have asthma. In fact, children who get the flu vaccine are more at risk for hospitalization than those who skip the shot.
In order to determine whether the trivalent inactivated flu vaccine was effective in reducing the number of child hospitalizations, researchers conducted a cohort study of close to 300 children. The investigators determined who had and had not received the flu vaccine, their asthma status and who did and did not require hospitalization.
They found that children who had received the flu vaccine had three times the risk of hospitalization. In asthmatic children, there was a significantly higher risk of hospitalization in subjects who received the vaccine.