By late July, pharmacies and health care providers usually begin advertising that influenza vaccinations are available. And each year, millions of Americans dutifully get flu shots, hoping to avoid pesky runny noses, body aches and sore throats. But when you receive your shot might affect the potency of the vaccine when flu season comes around.
According to a study by the Centers for Disease Control and Prevention, getting a flu shot too early might mean the vaccine loses effectiveness before the flu season even begins.
Researchers observed patients over the age of 9 who were seeking medical attention for acute respiratory illness. Throat and nasal swabs confirmed whether the patients had the flu, and researchers also determined when the patients received flu vaccines that year. The study was repeated over the course of four U.S. influenza seasons. Researchers found that the flu vaccine became less effective over time, though more research is needed to confirm why.
Though it can be unpredictable, over the past 18 years, flu season in America has followed a pattern of beginning in December or early January and lasting into the spring. For that reason, the Advisory Committee on Immunization Practices recommends people over the age of 6 months get their flu shots by October of each year so the potency will be strong when needed the most. It takes about 14 days after vaccination for a body’s immune system to begin protecting itself against the flu.
So if you’re planning on getting a flu shot later this year, consider the timing. You don’t want the vaccine’s benefits to be too little, too late.