Getting COVID and flu vaccines in the same arm or different arms is a matter of personal preference, with recent studies suggesting no significant difference in effectiveness or antibody response; convenience and comfort are key considerations.
Researchers at Oregon Health & Science University found that administering COVID-19 vaccine doses in different arms, rather than the same arm, may significantly boost the immune response. Their study of 947 participants showed that those who received shots in both arms had up to a four-fold increase in SARS-CoV-2-specific serum antibodies compared to those who got shots in just one arm, and this improved immune response lasted more than a year after the booster was administered. The findings suggest that switching arms for vaccine administration may enhance immunological function by triggering an immune response in two locations instead of one.