The flu season is almost upon us. While influenza activity peaks between December and February, people who are 65 years and older should consider getting their flu vaccine now. And because of their aging immune systems, they should think about getting a stronger vaccine than the standard-dose.

Although the Centers for Disease Control and Prevention (CDC) suggests that everyone over the age of 6 months get a flu shot by Halloween, Dr. Robert Hopkins Jr., medical director of the National Foundation for Infectious Diseases, urges older adults to protect themselves earlier.

According to Fortune Well, Hopkins says that seniors and people with chronic medical conditions should get their annual flu vaccine starting the middle of September through early October.

“In those of us with immune systems that aren’t quite as robust, we want to make sure that we vaccinate at a time that’s likely to give us immune protection throughout the flu season,” he says. The CDC notes that people over the age of 65 account for 70% to 80% of seasonal flu-related deaths and 50% to 70% of seasonal flu-related complications.

According to the CDC, all 2024-2025 flu vaccines are trivalent, which means they protect against three different influenza viruses. But the agency recommends the following specialized flu vaccines for those over the age of 64 because the standard-dose flu vaccine may not be enough to boost aging immune systems.

• Fluzone High-Dose vaccine. This vaccine manufactured by Sanofi offers four times the protection of standard-dose vaccines. It’s covered by Medicare Part B, most Medicare Advantage plans, and most private insurance plans. The Food and Drug Administration (FDA) approved the vaccine only for people ages 65 and older. Experts say that because it contains four times the amount of antigen than other vaccines, you may experience more side effects, such as local pain or fever.

• Fluad adjuvanted flu vaccine. Approved by the FDA for only those over 65, it is a standard-dose shot with the addition of an adjuvant called MF59, an oil-in-water emulsion that contains a naturally occurring substance called squalene. Fluad’s manufacturer, Seqirus, says that Medicare Part B and most Medicare Advantage plans cover the shot without a co-pay.  

• Flublok recombinant flu vaccine. This vaccine is not manufactured inside chicken eggs, the historical way flu vaccines have been manufactured in the past. Instead, the manufacturer, Sanofi, uses synthetic recombinant technology which is a quicker process. Flublok is FDA-approved for people over the age of 18 and may offer older adults enhanced protection. It contains three times the antigen of standard-dose vaccines and is the preferred vaccine of Medicare for people 65 years and older.

If you can’t obtain Fluzone, Fluad, or Flublok, the CDC recommends getting any protection available.