Dosing & Uses
Dosage Forms & Strengths
IM solution
- 0.5mL/vial
Influenza Prophylaxis
Indicated for active immunization against influenza virus subtypes A and B contained in the vaccine for adults aged ≥18 yr
0.5 mL IM x1/season
Dosing Considerations
Contents for 2019-2020 northern hemisphere season:
- A/Brisbane/02/2018 (H1N1)pdm09-like virus (New for 2019-2020)
- A/Kansas/14/2017 (H3N2)-like virus (New for 2019-2020)
- B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage) (no change from last season)
Egg allergy
- The Advisory Committee on Immunization Practices (ACIP) recommends FluBlok for vaccination of persons aged 18 through 49 years with egg allergy of any severity
- FluBlok does not use the influenza virus or chicken eggs in its manufacturing process
<18 years: Safety and efficacy not established
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Adverse Effects
>10%
Injection site pain (37%)
Headache (15%)
Fatigue (15%)
Muscle pain (11%)
1-10%
Nausea (6%)
Joint pain (4%)
Injection site redness (4%)
Injection site swelling/bruising (3%)
Chills (3%)
Warnings
Contraindications
Severe hypersensitivity (eg, anaphylaxis) to any component of the vaccine
Cautions
Expected immune response may not be obtained in immunocompromised individuals, including those receiving immunosuppressive therapy
Influenza vaccine may not protect all susceptible individuals
Guillain-Barre syndrome has been reported within 6 weeks of receipt of influenza vaccines
Pregnancy & Lactation
Pregnancy
Manufacturers are maintaining prospective pregnancy exposure registries to collect data on pregnancy outcomes following vaccination
Animal data
- No adverse effects observed on preweaning or vaccine-related fetal malformations when administered to female rabbits before pregnancy or during pregnancy
Clinical considerations
- Pregnant women are at increased risk of complication associated with influenza infection compared with nonpregnant women
- The CDC recommends pregnant women be immunized with influenza vaccine by injection and not the live attenuated influenza vaccine (LAIV; intranasal influenza vaccine)
- Vaccination has been shown to reduce the risk of flu-associated acute respiratory infection in pregnant women by up to 50%; immunization also confers some immunity to infants for the first several months after their birth, when they are too young to be vaccinated
Lactation
Unknown if distributed in human breast milk
Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for the drug, and any potential adverse effects on the breastfed infant from the drug or from the underlying maternal condition
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Recombinant HA proteins of the 3 strains of influenza virus specified for annual seasonal vaccine; these proteins function as antigens which induce a humoral immune response
Contains purified HA proteins produced in a continuous insect cell line (expresSF+) that is derived from Sf9 cells of the fall armyworm, Spodoptera frugiperda, and grown in serum-free medium composed of chemically-defined lipids, vitamins, amino acids, and mineral salts
Each of the three HAs is expressed in this cell line using a baculovirus vector (Autographa californica nuclear polyhedrosis virus), extracted from the cells with Triton X-100 and further purified by column chromatography; purified HAs are then blended and filled into single-dose vials that are standardized according to US Public Health Service (USPHS) requirements for each season viral subtypes
Administration
Instructions
Administer at beginning of influenza season
Should not be mixed with any other vaccine in the same syringe or vial
Shake well before administration
For IM injection only
Administer IM in deltoid muscle of upper arm
Storage
Store refrigerated between 2-8ºC (36-46ºF)
Do not freeze and protect from light
Images
Patient Handout
Formulary
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