Flu Vaccines — What’s right for you in 2025?

Flu season will be with us soon. It usually starts in October and runs through April in our part of the world, and is at its worst December through February. The 2024/25 season was brutal -- high severity, including hospitalizations and deaths, in all age groups. It's hoped that the 2025/26 season might be less severe. Each of us is in a position to help make that happen by getting vaccinated.

There's little change in CDC's recommendations for who should be vaccinated and when. Young children typically need two doses of flu vaccine the first season they get it. Everyone else (6 months and older) should get one vaccination every fall. September and October are the best times for vaccination - that ensures you're protected at both the start and end of the flu season. (Young children who need two doses can start before September if vaccine is available.) 

What's the difference between Inactivated Influenza Vaccine and Live, Attenuated Influenza Vaccine?

All influenza vaccines contain proteins (antigens) that cause our body to mount an immune response. Most flu vaccines use either pieces of inactivated virus or particles of live virus that have been weakened (attenuated) so they can't actually cause the flu. The immune system "sees" these particles as if they were really the flu virus. So the body produces proteins to fight off this invader, and for the next several months, if the real flu virus attacks us those proteins will fight it off to keep us from getting sick.

Inactivated virus is what most injectable flu vaccines contain. (The only exception is the new recombinant vaccine, described below.) They can't produce actual influenza infections, so they're safe and effective for most everyone who's 6 months and older. 

The only live, attenuated vaccine is a nasal mist (FluMist). It's intended for people between the ages of 2 and 49 and is great for folks who don't like needles. The weakened (attenuated) virus won't cause illness is people with a healthy immune system - instead it'll cause the body to develop immunity to the real virus. But because it's a live virus we have to be a little more cautious. A person with a weak immune system (from an organ transplant or treatment for some diseases) could become ill with influenza if they're exposed to this type of vaccine. Anyone who has a weak immune system should NOT be given live, attenuated flu vaccine. Not only that, but if you are a healthy person living with or caring for someone with a weak immune system, the live virus vaccine is not for you.

Starting this season FluMist will be available for at-home administration as well as administration in a pharmacy or clinic. If you're at least 18 years old, you can self-administer FluMist; younger people must have someone 18 or older administer it to them. If you're interested, you can learn more at the FluMist website.

"Trivalent" vs "Quadrivalent" Flu Vaccine

All influenza vaccines are manufactured to be effective against more than one strain of influenza. Those that work against two strains of Influenza A and one strain of Influenza B are called "trivalent". Vaccines that work against two strains of each type of Influenza are "quadrivalent". Experts decide each year how many strains are likely to circulate. For the 2025/26 season, all flu vaccines are trivalent.

Flu vaccines intended for older adults (65 and older)

As we age, our immune systems just don't kick in the way they used to. So it's tougher to mount an adequate immune response to vaccines. FDA has approved three vaccines that are intended provide better protection in older adults.

High-dose flu vaccine (Fluzone high-dose) contains about four times as much antigen as the standard-dose vaccines. The idea is that by giving a higher dose of the inactivated virus particles, the body will be more likely to produce an adequate response.

Adjuvanted flu vaccine (Fluad) has an added ingredient that helps "rev up" the immune system in older adults. The idea here is that the added ingredient will cause a more efficient immune response to the vaccine.

Recombinant flu vaccine (Flublok) is made with a whole new technology. Instead of using pieces of virus, it uses a part of the virus's genetic code. That code is inserted into an insect cell which then churns out proteins that can induce an immune response to the flu virus. It's pretty quick to manufacture compared to other vaccines. And it turns out that this type of vaccine seems to induce a better immune response in older adults. Flublok is approved for anyone 9 or older.

Is it necessary for older adults to get a special vaccine?

As mentioned above, research points to improved efficacy with the high-dose, adjuvanted, and recombinant vaccines in those 65 and over. But without detailed information about how much the immune response improves, who's most likely to benefit, and frequency of side effects, experts recommend flexibility. If for some reason your provider doesn't have one of them, and you can't be sure you'll have time to come back again, it's best to get whatever age-appropriate vaccine they have in stock. You'll still be better protected than if you don't get vaccinated.

What about people who are allergic to eggs?

The amount of egg protein in flu vaccines is extremely low. Experts have learned that the benefit of immunization far outweighs the very small risk of an allergic reaction. For those with egg allergy, including stomach discomfort or nausea, rash, and hives, vaccination with any age-appropriate product is recommended.

If you have a more severe egg allergy, you should still get vaccinated. You can ask for the recombinant vaccine (Flublok contains no egg protein); if it's not available get your vaccine at your doctor's office where they can watch you for 15-30 minutes afterward.

What about mercury?

The vast majority of flu vaccine contains no thimerosal (mercury) as a preservative. When  thimerosal is used, it's there in extremely low amounts -- research has shown that it's not a danger to children or adults. Even so, experts recommend that flu vaccine given to children should always be mercury-free.

Get vaccinated to be protected during the coming flu season!

You won't have any trouble finding flu vaccine this year. Make your appointment now to protect yourself and your loved ones from the flu and its complications. If you have other questions about vaccination, ask your community pharmacist, or contact us at BetterMyMeds. We love hearing from you!

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