Influenza Vaccine
Influenza Vaccine is a preventive immunization that protects against seasonal influenza virus infections. It is recommended for most individuals, particularly those at higher risk of complications such as older adults, young children, pregnant women, and people with certain chronic medical conditions. Annual vaccination is advised since influenza strains change yearly and vaccine effectiveness varies by season.
Influenza Vaccine is a yearly immunization that protects against seasonal flu viruses by stimulating the immune system to produce antibodies.
Key facts at a glance
- ATC
- J07BB02
- Generic
- Influenza Vaccine
- Class
- vaccine
- Brands
- Fluzone, Fluarix
- Availability
- behind_counter
- Pregnancy
- C
- Lactation
- safe
- Onset (min)
- 10080
- Routes
- im, sc
- Forms
- injection
- Regions
- CN, US, EU, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 0.5mL (one dose)
- Maximum
- consult physician
- Frequency
- annually
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 0.5mL (two doses, 4 weeks apart)
- Maximum
- consult physician
- Frequency
- annually after initial series
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 0.5mL (one dose)
- Maximum
- consult physician
- Frequency
- annually
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
7 groupspregnancy
all trimestersstandard dose recommended
CDC recommends influenza vaccination during any stage of pregnancy to protect both mother and fetus from influenza complications
standard prenatal care
lactation
breastfeeding mothersstandard dose recommended
influenza vaccine is safe for breastfeeding mothers and does not affect lactation
none
geriatric
65 years and olderhigh-dose or adjuvanted vaccine recommended
annual influenza vaccination strongly recommended using high-dose or adjuvanted formulations for enhanced immune response
standard post-vaccination observation
pediatric_age
6 months to 5 yearsage-appropriate dosing required
annual influenza vaccination recommended for all children 6 months and older; some may require 2 doses initially
standard post-vaccination observation
renal_impairment
all stagesstandard dose recommended
influenza vaccination is recommended for all patients with renal impairment including those on dialysis
standard observation
hepatic_impairment
all stagesstandard dose recommended
influenza vaccination is recommended for patients with chronic liver disease
standard observation
other
immunocompromisedstandard dose recommended
influenza vaccination is strongly recommended for immunocompromised patients; inactivated vaccine preferred over live attenuated
standard observation
Statistics and clinical data
First FDA approved influenza vaccine
First influenza vaccine approved in the United States
Drug class
Classification of influenza vaccines under ATC system
Common uses
Primary indication for influenza vaccination
Vaccine effectiveness
Average effectiveness in reducing flu illness
Prevention of influenza virus infection. Recommended annually for all individuals 6 months and older, with particular emphasis for high-risk groups including seniors over 65, young children under 5, pregnant women, immunocompromised patients, and those with chronic conditions like asthma, diabetes, or heart disease.
The vaccine contains inactivated (killed) or attenuated (weakened) influenza virus antigens that stimulate the immune system to recognize and produce antibodies against circulating flu strains. This immune response allows the body to quickly fight off infection if exposed to the actual virus.
Administered annually before flu season (typically fall). Common mild side effects include soreness, redness, or swelling at the injection site, low-grade fever, and muscle aches. Severe allergic reactions are rare. The vaccine cannot cause influenza since it contains non-replicating or highly weakened virus. Effectiveness varies each season depending on how well the vaccine matches circulating strains.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 22, 2026. · Read our editorial policy