Unless you are just getting over COVID-19 (in which case you can wait three months from the onset of symptoms, according to the CDC), make sure you get your booster shots on schedule. Other than getting all of your vaccinations, there are a few lifestyle changes which can boost your immune system. Not smoking, not drinking excessively, exercising regularly and following a healthy diet,†according to infections disease expert Dr. Lawrence Liverornese, chairman of the department of medicine at Main Line Health System, can boost your immune system, he told AARP Bulletin. COVID-19 can also cause other problems—older adults are six times more likely to suffer a heart attack within a week of catching the flu. Also, make sure to get your flu shot, although do know that this is not 100% protection (there are more than 200 viruses out there, and vaccinations can’t cover every one of them).