Which Flu Shot Is the Most Effective for the 2024-2025 Flu Season?
Key takeaways:
There are nine flu vaccines available for the 2024-2025 flu season. The flu vaccine is typically about 40% to 60% effective against needing to see a healthcare professional for flu treatment.
Some flu vaccines may be a better option for certain people, including older adults and those with life-threatening egg allergies.
It’s ideal to get your flu vaccine before the end of October. But getting vaccinated later than that is still beneficial.
Table of contents
With flu season beginning to pick up in October, you’ve probably been seeing signs or advertisements telling you to get your annual flu shot. But with several flu vaccine options to choose from, it can be confusing to know which one to pick. Does it really make a difference which one you get? And just how effective is the flu vaccine?
Quiz: Test your flu shot knowledge
What you need to know about the 2024-2025 flu season
While no one knows for sure just how bad the upcoming flu season will be, here’s some flu information we know so far:
The 2023-2024 flu season was considered “moderate” in severity. It’s estimated that up to 75 million people in the U.S. got the flu last year. And as many as 72,000 people died from it. Experts aren’t sure if the 2024-2025 season will be more or less severe than last year.
Flu transmission rates in other countries are about the same this flu season as they were during the previous season. The World Health Organization (WHO) meets twice a year — in February and September — to review flu activity around the world and recommend which strains to include in the flu vaccine. Flu transmission in the Southern Hemisphere countries — like Australia — can help predict what the U.S. flu season might be like. Australia’s 2024 flu season was about the same as their 2023 season. That could mean the U.S. 2024-2025 flu season may be similar to last year’s flu season, too.
Even though the flu vaccine doesn’t protect against all strains of the flu, it’s still recommended for everyone over the age of 6 months. The flu vaccine is typically about 40% to 60% effective against needing to see a healthcare professional for flu treatment, and it’s hard to predict if the current flu vaccines will be a good match for the strains going around. But it’s still one of the best ways to help prevent getting sick or severely ill with the flu.
What vaccines are available for the 2024-2025 flu seasons?
There are nine vaccines that have been FDA approved for the 2024-2025 flu season. This year, all FDA-approved flu vaccines are trivalent — meaning they protect against three different strains of influenza (the virus that causes the flu). Here’s a rundown of the available flu vaccines for the year.
Vaccine name | Age range | How it’s given | Potential allergens |
|---|---|---|---|
6 months or older | Intramuscular | Thimerosal (multiple-dose vials only), egg protein, neomycin, polymyxin | |
65 years or older | Intramuscular | Egg protein, kanamycin, neomycin, polysorbate 80 | |
6 months or older | Intramuscular | Egg protein, gentamicin, polysorbate 80 | |
18 years or older | Intramuscular | Polysorbate 20 | |
6 months or older | Intramuscular | Thimerosal (multiple-dose vials only), polysorbate 80 | |
6 months or older | Intramuscular | Egg protein, polysorbate 80 | |
2-49 years | Nasal spray | Egg protein, gentamicin, pork gelatin, monosodium glutamate (MSG), ethylenediaminetetraacetic acid (EDTA) | |
6 months or older | Intramuscular | Thimerosal (multiple-dose vials only), egg protein | |
65 years or older | Intramuscular | Egg protein |
It’s important to note that pharmacists and other healthcare professionals may only carry a few brands of flu vaccine at a time — not all nine that are FDA approved. If you are interested in or know you need a certain flu vaccine, it’s best to call ahead and see if your preferred vaccine is available.
How effective are the flu vaccines this year?
Experts never know ahead of time how effective flu vaccines will be. But on average, the flu vaccine is about 40% to 60% effective against needing to see a healthcare professional for flu treatment. Last year, it was about 42% effective.
When flu vaccines are being produced, the strains they protect against are standardized by the FDA. Each 2024-2025 vaccine protects against:
Two type A flu viruses (H1N1 and H3N2)
One type B virus (Victoria lineage)
This means that no matter what vaccine you choose, you’re being protected against the same strains. But when it comes to picking the right flu vaccine for you, you have to take other factors into account.
The best flu vaccine for people over 65
As we get older, our immune systems have a harder time responding to illnesses and vaccines. To help provide better protection, there are a few recommended options for older adults this year:
Fluzone High-Dose — also known as the “high-dose flu shot”
Fluad
Flublok
Does the flu vaccine work? Physicians detail how flu vaccinations work and why they’re beneficial for everyone.
Is the flu vaccine a live virus? Most flu vaccines are inactivated (dead virus) vaccines. Read more pharmacist-backed answers to common flu vaccine questions.
All about FluMist: Read about the nasal spray flu vaccine and who’s eligible to receive it.
If one of these three vaccines isn’t available, you should still get vaccinated with another flu vaccine that’s FDA approved for your age range. All flu vaccines are effective against the flu. It’s better to be vaccinated than to try to wait or shop around for a particular flu vaccine to become available.
The best flu vaccine if you have egg allergies
Many flu vaccines are made using chicken eggs — called egg-based vaccines. While most people with egg allergies are still able to receive egg-based flu vaccines, there are rare instances where they can cause life-threatening allergic reactions.
If this is the case for you or if you’re concerned, Flucelvax and Flublok are two egg-free flu vaccine options. But remember, Flublok is only FDA approved for adults 18 and older. If you’re getting your child vaccinated and they have a severe egg allergy, you’ll want to ask a pharmacist or other healthcare professional if they have Flucelvax available.
The best flu vaccine if you’re scared of needles
While most people use the terms “flu vaccine” and “flu shot” interchangeably, not all flu vaccines use a needle to deliver the ingredients.
FluMist is a nasal spray vaccine. However, it’s not the right choice for some people. This vaccine is only FDA approved for people between ages 2 and 49 years old. FluMist is also a live attenuated vaccine, meaning it contains weakened versions of the flu viruses instead of inactivated (dead) viruses. If you’re pregnant or have certain health problems — such as a weakened immune system — you shouldn’t receive it.
When should you get your flu vaccine?
It’s ideal to get vaccinated against the flu during September or October.
Flu vaccine effectiveness can have a lot to do with when you get it. It’s recommended to get your flu vaccine about 2 weeks before flu season begins in your area — preferably by the end of October. However, if you get the flu vaccine too early — July or August, for instance — you may not be protected for the entire flu season.
While September or October are the ideal times to get your flu vaccine, it’s still recommended to get it later than that if you were unable to do so earlier. If you’re unsure when flu season begins in your area, talk to your local pharmacist or other healthcare professional.
If you’ve recently received or will be receiving a COVID-19 vaccine, you don’t have to wait a certain time to get the flu vaccine. You can even get them on the same day, if that’s more convenient. These two vaccines don’t interfere with each other.
Frequently asked questions
Flu vaccine immunity — meaning immune system protection — doesn’t last long. After about 5 to 6 months, your immunity starts to fade. This falling level of protection (from a lessening amount of antibodies), combined with ever-mutating flu viruses, means it’s important to be vaccinated for the flu every year.
No, flu vaccines don’t cause the flu. However, some people experience flu-like symptoms, such as muscle aches or a low fever, in the days that follow their vaccine. These are side effects of the flu vaccine, and it’s a sign your immune system is learning how to fight the flu virus. These are expected and don’t mean you’re getting sick with the flu. They should go away within a few days.
Yes, the flu shot can prevent the flu. But the effectiveness varies each year, depending on what flu strains are going around. However, the flu vaccine offers benefits beyond just flu prevention. If you get the flu even though you were vaccinated, you're much less likely to have severe symptoms or experience flu-related complications. And if you’re pregnant, getting your annual flu vaccine protects your baby both during your pregnancy and for the first few months after birth.
The bottom line
There are nine options for flu vaccines for the 2024-2025 flu season. No matter which one you choose, flu vaccine effectiveness should be the same — 40% to 60% effective on average. Some flu vaccines may be a better choice for certain groups of people, such as older adults and people with life-threatening egg allergies. If you’re still questioning which flu vaccine is right for you, make it a point to talk to your pharmacist or other healthcare professional and get vaccinated this fall.
Why trust our experts?
References
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Centers for Disease Control and Prevention. (2024). 2023-2024 United States flu season: Preliminary in-season severity assessment.
Centers for Disease Control and Prevention. (2024). ACIP recommendations summary.
Centers for Disease Control and Prevention. (2024). Benefits of the flu vaccine.
Centers for Disease Control and Prevention. (2024). CDC seasonal flu vaccine effectiveness studies.
Centers for Disease Control and Prevention. (2024). Preliminary estimated flu disease burden 2023–2024 flu season.
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Sanofi Pasteur Inc. (2024). Fluzone trivalent northern hemisphere (influenza a virus a/victoria/4897/2022 ivr-238 (h1n1) antigen (formaldehyde inactivated), influenza a virus a/california/122/2022 san-022 (h3n2) antigen (formaldehyde inactivated), and influenza b virus b/michigan/01/2021 antigen- formaldehyde inactivated injection, suspension [package insert]. DailyMed.
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Seqirus PTY LTD. (2024). Afluria (influenza a virus a/victoria/4897/2022 ivr-238 (h1n1) antigen (propiolactone inactivated), influenza a virus a/thailand/8/2022 ivr-237 (h3n2) antigen (propiolactone inactivated), influenza b virus b/austria/1359417/2021 bvr-26 antigen- propiolactone inactivated injection, suspension [package insert]. DailyMed.
