Vaccination against influenza has been linked to lower use of antibiotics, according to a study in Antimicrobial Resistance and Infection Control. However, the same can’t necessarily be said of the pneumococcal vaccine.

The review and meta-analysis looked at data from 1998 to 2021, most of it conducted in the Americas and Europe. Randomized controlled trials showed a more pronounced impact from flu shots on the number of prescriptions for antibiotics as well as days a person needed to take antibiotics, the study reported. That correlation wasn’t as strong when the authors looked at how the pneumococcal vaccine affects antibiotic use. 

When reviewing different types of studies, the team noted that both randomized controlled studies and observational studies revealed that administration of the influenza vaccine can significantly reduce antibiotic use. Observational studies weren’t as consistent, they said.

Researchers were surprised that they found a stronger effect with the flu shot, because people don’t treat the flu with antibiotics. They were also surprised because the vaccine effectiveness of the pneumococcal vaccine is considerably higher than that for the influence vaccine. 

The pneumococcal vaccine addresses illnesses caused by Streptococcus pneumoniae bacteria. Pneumococcal disease refers to infections caused by the bacteria, and can include sinus infections, ear infections, pneumonia and infections in the blood. Researchers contend that people should use both vaccines.

Getting a flu shot is an important way to lower the use of antibiotics and perhaps control the issue of antimicrobial resistance, according to the researchers.