Ever since the COVID vaccine became widely available in the spring of 2021, people have been wondering how often they’ll need a booster shot. Some people – particularly those at high risk – are already on their fifth or sixth shot. But a new study from Yale University suggests that once a year looks to be the optimal frequency. Researchers found that a yearly shot will reduce your risk of infection by 75%. Although that number climbs to 93% if you get a jab every six months, for most people that’s more trouble than the additional protection is worth – when you consider the inconvenience of getting the shot and then the possibility of a couple days of side effects. On the other hand, the risk of infection rises significantly if you wait more than a year -- you’ll be just 55% protected after 18 months, and 24% after three years. So as we emerge from the pandemic phase of COVID, expect to get a booster shot once a year, just like you do with the flu shot.