The flu virus is already causing some serious problems for people.
Now, a new study finds that the virus can cause problems in children too.
In a study published today in JAMA Pediatrics, researchers from the University of Texas at Dallas found that flu vaccine efficacy was reduced in children who had received flu shot after age 6 months.
The findings may explain why a second dose of the vaccine is still not available to all children, even if parents have received one dose.
“Our findings indicate that the flu vaccine’s efficacy may be lower in children with a history of influenza, even when the vaccine was given prior to age 6,” said study author Michael Kranz, MD, PhD, associate professor of pediatrics at the University at Dallas.
“This suggests that children who have influenza may have a higher chance of receiving a second influenza vaccine dose if their parents had received a second vaccine prior to vaccination.”
The findings are consistent with the results of an earlier study that looked at children who received a flu shot between the ages of 6 and 12 months.
In that study, a third of children who got the flu shot within the first year of age also got a second shot in the same age group.
“This study suggests that the efficacy of the flu vaccination for children with influenza may be less than for children who do not have influenza,” Kranpah said.
“It’s important to note that these findings do not prove that the effectiveness of the second dose is superior to that of the first dose.”
Parents who have received the second flu vaccine are now asked to complete an online questionnaire that is designed to help them better understand the flu and its side effects.
If the survey is completed successfully, the CDC will then provide more information about flu vaccines to parents.
The vaccine is designed for adults ages 65 and older, but children can get it as young as 6 months of age.
For more information on flu vaccines, visit the CDC website.
Read the study abstract here.