Fluzone and Fluzone High-Dose Flu Vaccine: 2026-27 Strains, Dosage, and Side Effects
Medically reviewed by Lauren Okafor | MD on August 23rd, 2026 and Alan Lucks | MD on November 4th, 2026.
Published on March 3rd, 2026.
Key Takeaways
Fluzone is an inactivated flu vaccine that protects against seasonal influenza viruses.
It's given as a single annual injection and is safe for most people ages 6 months and older.
For adults 65 and older, the CDC preferentially recommends Fluzone High-Dose, Flublok or Fluad over standard-dose shots.
Common side effects are mild and temporary, like arm soreness or low fever.
The vaccine works best when given before flu season starts (September or October is ideal).
Fluzone Overview: What's in the 2026-27 Vaccine
Fluzone is an inactivated influenza vaccine designed to protect you and your family from seasonal flu viruses. It belongs to the class of vaccines called immunizations, which help your immune system recognize and fight specific diseases before you get sick. The vaccine contains inactivated (killed) virus, not live virus, so it cannot give you the flu.
For the 2026-27 season, Fluzone is an egg-based, trivalent vaccine. It protects against three strains: A/Missouri/11/2025 (H1N1)pdm09-like, A/Darwin/1454/2025 (H3N2)-like and B/Tokyo/EIS13-175/2025 (B/Victoria)-like. All three strains are updated from the 2025 to 2026 season, including a new H3N2 strain that targets subclade K.
How it works: When you receive Fluzone, your immune system learns to recognize flu virus proteins. If you're exposed to the flu later, your body is ready to fight it off. In seasons when the vaccine is well matched to circulating strains, it can reduce your chances of getting sick with flu by about 40-60%.
You get it once a year, ideally before flu season peaks (December through February in the Northern Hemisphere). It's recommended for almost everyone age 6 months and older, including pregnant women, adults 65 and older, and people with chronic health conditions.
Fluzone High-Dose for Adults 65 and Older
For adults 65 and older, the CDC preferentially recommends one of three flu vaccines over standard-dose shots: a high-dose vaccine (Fluzone High-Dose), a recombinant vaccine (Flublok) or an adjuvanted vaccine (Fluad).
Timing matters too. Adults 65 and older should avoid getting vaccinated in July or August, because protection wanes over the season.
Not sure which option fits you? A licensed doctor on Doctronic can talk it through with you by video.
When to Get Fluzone in 2026
September or October is the ideal time to get Fluzone. That gives you protection before flu season peaks.
Missed that window? Getting vaccinated later in the season is still worthwhile.
Children who need two doses should get dose 1 as soon as vaccine is available. That way, dose 2 can follow at least 4 weeks later.
For a closer look, see flu season 2026: when to get your shot.
Fluzone Dosage by Age
Children 6 months to 8 years who haven't had at least 2 flu vaccine doses before July 1, 2026 need 2 doses, at least 4 weeks apart.
Age Group |
Dose |
Frequency |
Important Notes |
|---|---|---|---|
6 months to 8 years (fewer than 2 prior flu vaccine doses before July 1, 2026) |
0.5 mL |
Two doses, at least 4 weeks apart |
Give dose 1 early so dose 2 fits in. |
6 months to 8 years (2 or more prior doses before July 1, 2026) |
0.5 mL |
Once yearly |
One dose this season is enough. |
9 years and older |
0.5 mL |
Once yearly |
A single annual injection is the standard dose for older children and adults. |
Adults 18-64 years |
0.5 mL |
Once yearly |
Given before flu season, ideally September or October. |
Adults 65 years and older |
0.5 mL (standard) or 0.7 mL (Fluzone High-Dose) |
Once yearly |
Fluzone High-Dose is recommended over standard-dose Fluzone for adults 65 and older; ask your doctor. |
Side Effects
Fluzone is generally well tolerated. Most side effects are mild and resolve within a few days. Serious side effects are rare. For more on common reactions, see this guide to flu shot side effects.
Common Side Effects
Arm soreness or redness: Tenderness at the injection site is normal and usually goes away in 1-2 days.
Low-grade fever: A mild fever (99-101°F) may develop within 24 hours and typically lasts 1-2 days.
Fatigue: Some people feel tired or have mild body aches for a day or two.
Headache: A mild headache may occur but usually resolves without treatment.
Muscle aches: Temporary soreness in muscles throughout the body is possible but minor.
Serious Side Effects
Guillain-Barré Syndrome (GBS): A rare neurological condition causing muscle weakness; occurs in roughly 1-2 cases per million vaccinations.
Severe allergic reaction (anaphylaxis): Difficulty breathing, swelling of face or throat, or hives; requires immediate medical attention.
High fever: A fever above 103°F is uncommon but needs evaluation.
When to Seek Medical Attention
Get emergency care right away if you have signs of a serious allergic reaction, such as difficulty breathing, swelling of your face or lips, or hives. Call your doctor if you develop a high fever (above 103°F), severe muscle weakness, or tingling in your legs that spreads upward. Most reactions occur within 15 minutes of vaccination, so your doctor may ask you to wait in the office for observation. If you have symptoms days later, don't wait: reach out to your doctor or seek urgent care.
Fluzone Interactions and Timing With Other Vaccines
Fluzone may interact with other medications or treatments, though serious interactions are uncommon. Tell your doctor about all vaccines, medications and supplements you take before your shot. For tips on the day of your shot, see what to avoid after a flu shot.
Live Attenuated Influenza Vaccine (LAIV)
Fluzone (inactivated) and LAIV (the FluMist nasal spray, live) are both flu vaccines. You need only one flu vaccine per season, so most people get one or the other, not both.
Other Live Vaccines (Measles, Mumps, Rubella; Chickenpox; Rotavirus)
Fluzone is an inactivated vaccine, so it can be given at the same visit as, or any time before or after, live vaccines such as MMR or chickenpox. Ask your doctor which other vaccines you're due for.
Blood Thinners (Warfarin, Apixaban, Dabigatran)
Fluzone is safe with blood thinners, but tell your doctor before vaccination. A blood thinner slightly increases bruising risk at the injection site, so your doctor may recommend applying pressure or ice afterward.
Immunosuppressants and Immunosuppressive Medications
If you take medications that weaken your immune system (for example, corticosteroids or biologics for autoimmune conditions), discuss vaccine timing with your doctor. Fluzone may be less effective, or your doctor may recommend special scheduling or alternative vaccines.
Antiviral Flu Medications (Oseltamivir, Zanamivir)
Flu antivirals such as oseltamivir and zanamivir don't affect inactivated vaccines like Fluzone, so timing doesn't matter. They can reduce the effect of the live nasal spray (FluMist). If you're sick with flu, get vaccinated once you feel better.
Other 2026-27 Flu Vaccine Options
Fluzone isn't the only flu vaccine for the 2026-27 season. Other choices include Flublok, a recombinant vaccine that is egg-free, and Fluad, an adjuvanted vaccine for adults 65 and older.
FluMist Home: A nasal spray. It's self-given for ages 18 to 49 or given by a caregiver for ages 2 to 17. It ships to the 48 contiguous states. It isn't for pregnant people or people who are immunocompromised.
mFlusiva: An mRNA flu vaccine approved August 5, 2026 for adults 50 and older. The CDC's vaccine advisory committee (ACIP) hasn't voted on it yet, so insurance coverage may vary.
Vaccine |
Approved ages |
Vaccine type |
Route |
|---|---|---|---|
Fluzone |
6 months and older |
Inactivated, egg-based |
Injection |
Fluzone High-Dose |
65 and older |
Inactivated, egg-based, high-dose |
Injection |
Flublok |
9 years and older |
Recombinant |
Injection |
Fluad |
65 and older |
Adjuvanted |
Injection |
FluMist Home |
2 to 49 years |
Live attenuated |
Nasal spray |
mFlusiva |
50 and older |
mRNA |
Injection |
Pros and Cons
Pros
Proven effectiveness: When the vaccine is well matched to circulating strains, it reduces flu illness risk by about 40-60%. If you do get sick, symptoms are often milder.
Simple, quick administration: Single annual injection takes less than 5 minutes.
Safe for most ages: Approved for anyone 6 months and older, including pregnant women.
Reduces serious complications: Decreases risk of flu-related hospitalization, pneumonia, and death, especially in vulnerable populations.
Widely available: Offered at pharmacies, doctor's offices, and clinics throughout flu season.
Cons
Annual requirement: You must get vaccinated every year because flu viruses change and immunity wanes.
Not 100% effective: Protection is about 40-60% in seasons when the vaccine is well matched to circulating strains, so some vaccinated people still get the flu.
Common side effects: Arm soreness, mild fever, or fatigue may occur, though these are temporary.
Rare serious side effects: GBS and severe allergic reactions are uncommon but serious.
Frequently Asked Questions
Get answers to common questions about Fluzone.
In seasons when the vaccine is well matched to circulating strains, Fluzone can reduce your risk of getting sick with flu by about 40-60%. Even if you do get sick, the vaccine often makes illness milder and reduces the chance of serious complications like hospitalization or pneumonia. Protection is not 100%, but it's your best defense against seasonal flu. Learn more about the 2026 flu shot: timing and effectiveness.
No. Fluzone contains inactivated (killed) flu virus particles, not live virus. It cannot cause flu infection. Some people confuse mild side effects (like low-grade fever or fatigue) with actual flu, but these reactions are your immune system learning to fight the real virus.
September or October is ideal. Later is still worth it: even a shot in January or February protects you for the rest of the season. Talk to your doctor about the best timing for your situation.
Yes. Fluzone (inactivated vaccine) is safe during all stages of pregnancy and is strongly recommended. The vaccine protects you and may provide antibodies that help protect your newborn in the first months of life. Pregnant women are at higher risk for severe flu complications, making vaccination especially important. Read more about getting a flu shot while pregnant.
People with egg allergy can get any flu vaccine appropriate for their age, including Fluzone, with no extra precautions beyond those for any vaccine.
Fluzone is trivalent for the 2026-27 season. It protects against two influenza A strains and one B/Victoria strain. No U.S. flu vaccine is quadrivalent this season.
Fluzone High-Dose is for adults 65 and older. For this age group, the CDC preferentially recommends it, or Flublok or Fluad, over standard-dose flu vaccines.
Still have questions?
Doctronic's medical AI can help you weigh your flu vaccine options, free, any hour. A licensed doctor is available by video if you want one.
The Bottom Line
Fluzone is a safe, effective annual vaccine that protects you and your loved ones from seasonal influenza. While mild side effects like arm soreness or low-grade fever are common, serious side effects are rare. Getting vaccinated each year before flu season is one of the most powerful steps you can take to avoid illness, prevent hospitalization and protect vulnerable people in your community.
For 2026-27, get it in September or October. If you're 65 or older, ask for Fluzone High-Dose, Flublok or Fluad.
Not sure which flu vaccine fits you, especially with allergies, pregnancy or a health condition? Free medical AI chat is available any hour, and a licensed doctor is available by video for $39.
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Your age, pregnancy, allergies or a health condition can change which 2026-27 flu vaccine fits you: Fluzone, Fluzone High-Dose, Flublok, Fluad, FluMist Home or mFlusiva. Start a free chat to sort it out, and a licensed doctor is available by video if you want one.
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