Flu shots have small beneficial effect in reducing middle ear infections for infants and children.
Middle ear infection or inflammation are broad terms to refer to acute otitis media. It is one of the most common infectious diseases in infants and preschool children, with 86% having an episode by the time they turn one year old. Symptoms of an ear infection include ear pain and fever, but it may cause hearing loss due to ear drum perforation or fluid accumulation in the middle ear. Ear infections are usually bacterial in origin and is commonly triggered by a viral infection. Antibiotics are often used in treatment but they carry their own side effects and the risk of antibiotic resistance. Influenza vaccines, more commonly referred to as flu shots, are approved for infants after six months. They prevent viral infections, thus may prevent the onset of an ear infection.
A team of Cochrane authors, based in Malaysia and working with the Acute Respiratory Infections Group, set out to study the effect of the flu shot in preventing middle ear infections in infants and children. Included in their study were 10 randomised controlled trials involving 16,707 children aged six months to six years. Nine out of the 10 studies were funded by vaccine manufacturers. The overall quality of the evidence was high to moderate.
The primary outcomes showed a small reduction in at least one episode of middle ear inflection over at least six months of follow up (between 2 and 7%). There was also a reduction in the use of antibiotics in vaccinated children (between 0% and 30%). It remained uncertain whether it reduced visits to the healthcare facilities or hospital admissions. No major adverse events were reported.
“With the flu shot, we saw a small reduction in middle ear infections and a reduction in the use of antibiotics” said Norhayati M Noor, a researcher in Universiti Sains Malaysia, Kelantan, Malaysia, and the lead author of the Cochrane Review. “Given the small reduction and the current practice of avoiding the overuse of antibiotics, promoting the flu shot solely to reduce middle ear infections does not seem justified but the results may be useful to parents when making a decision to vaccinate their children. We recommend that future studies on flu vaccines will include ear infections as an outcome and provide detailed safety data.”