"The 2009 swine flu virus (otherwise known as H1N1 influenza) is caused by an H1N1 influenza A virus. H1N1 influenza viruses are the normal cause of influenza in humans and may also infect other animals, including pigs. This particular var"...
Flulaval Side Effects Center
Medical Editor: John P. Cunha, DO, FACOEP
Flulaval (Influenza Virus Vaccine) is an immunization used to prevent infection caused by influenza virus. The vaccine is redeveloped each year to contain specific strains of inactivated (killed) flu virus that are recommended by public health officials for that year. The injectable influenza virus vaccine (flu shot) is a "killed virus" vaccine. Common side effects include low fever, chills; mild fussiness or crying in children; redness, bruising, pain, swelling, or a lump where the vaccine was injected; headache, tired feeling; or joint or muscle pain.
Flulaval is administered as a single 0.5-mL dose injection intramuscularly, preferably in the deltoid muscle of the upper arm. Flulaval may interact with phenytoin, theophylline, blood thinner, steroids, medicines to treat or prevent organ transplant rejection, or medications to treat psoriasis, rheumatoid arthritis, or other autoimmune disorders. Tell your doctor all medications and supplements you use and all vaccine you recently received. Vaccines may be harmful to a fetus and generally should not be given to a pregnant woman. However, not vaccinating the mother could be more harmful to the baby if the mother becomes infected with a disease that this vaccine could prevent. Consult your doctor about whether you should receive Flulaval. It is unknown if Flulaval vaccine passes into breast milk or if it could harm a nursing baby. Consult your doctor before breastfeeding.
Our Flulaval (Influenza Virus Vaccine) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What is Patient Information in Detail?
Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.
Flulaval in Detail - Patient Information: Side Effects
Influenza virus injectable (killed virus) vaccine will not cause you to become ill with the flu virus that it contains. However, you may have flu-like symptoms at any time during flu season that may be caused by other strains of influenza virus.
You should not receive a booster vaccine if you had a life-threatening allergic reaction after the first shot.
Keep track of any and all side effects you have after receiving this vaccine. If you ever need to receive influenza virus vaccine in the future, you will need to tell your doctor if the previous shot caused any side effects.
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
- severe weakness or unusual feeling in your arms and legs (may occur 2 to 4 weeks after you receive the vaccine);
- high fever;
- seizure (convulsions); or
- unusual bleeding.
Common side effects may include:
- low fever, chills;
- mild fussiness or crying;
- redness, bruising, pain, swelling, or a lump where the vaccine was injected;
- headache, tired feeling; or
- joint or muscle pain.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report vaccine side effects to the US Department of Health and Human Services at 1-800-822-7967.
Read the entire detailed patient monograph for Flulaval (Influenza Virus Vaccine) »
What is Prescribing information?
The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.
Flulaval FDA Prescribing Information: Side Effects
Clinical Trials Experience
In adults who received FLULAVAL, the most common ( ≥ 10%) solicited local adverse reactions were pain (51%), redness (13%), and swelling (11%); the most common ( ≥ 10%) solicited systemic adverse events were fatigue (20%), headache (18%), and muscle aches/arthralgia (18%).
In children 3 through 17 years of age who received FLULAVAL, the most common ( ≥ 10%) solicited local adverse reaction was pain (56%). In children 3 through 4 years of age, the most common ( ≥ 10%) solicited systemic adverse events were irritability (25%), drowsiness (19%), and loss of appetite (16%). In children 5 through 17 years of age, the most common ( ≥ 10%) systemic adverse events were muscle aches (24%), headache (17%), and fatigue (17%).
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a vaccine cannot be directly compared to rates in the clinical trials of another vaccine, and may not reflect the rates observed in practice. There is the possibility that broad use of FLULAVAL could reveal adverse reactions not observed in clinical trials.
FLULAVAL in Adults
Safety data was obtained from 3 randomized, controlled trials, one of which was a placebo-controlled efficacy study. In these trials, 9,836 subjects were randomized to receive either FLULAVAL (5,114 subjects in the safety analysis), FLUZONE, a US-licensed trivalent, inactivated influenza vaccine, manufactured by Sanofi Pasteur SA (894 subjects in the safety analysis), or placebo (3,828 subjects in the safety analysis), intramuscularly. In these studies, solicited events were collected for 4 days (i.e., 30 minutes postvaccination through the next 3 days). Unsolicited adverse events that occurred within 22 days of vaccination (day 0-21) were recorded based on spontaneous reports or in response to queries about changes in health status.
Study 1 (Immunogenicity)
Safety information was collected in a randomized, controlled US study. This study included 1,000 adults 18 through 64 years of age who were randomized to receive FLULAVAL (N = 721) or a US-licensed trivalent, inactivated influenza vaccine (N = 279). Among recipients of FLULAVAL, 57% were female; 91% of subjects were white and 9% were of other racial/ethnic groups. The mean age of subjects was 38 years; 80% were 18 through 49 years of age and 20% were 50 through 64 years of age.
Study 2 (Immunogenicity Non-Inferiority)
Safety information was collected in a randomized, double-blind, active-controlled US study. The study included 1,225 adults ≥ 50 years of age randomized to receive FLULAVAL (N = 610) or a US-licensed trivalent, inactivated influenza vaccine (N = 615). In the total population, 57% were female; 95% of subjects were white and 5% were of other racial/ethnic groups. The mean age of subjects was 66 years; 46% were 50 through 64 years of age, 41% were 65 through 79 years of age, and 13% were ≥ 80 years of age.
Study 3 (Efficacy)
Safety information was collected in a double-blind, placebocontrolled US study. The study included 7,658 adults 18 through 49 years of age randomized to receive FLULAVAL (N = 3,807) or placebo (N = 3,851). In the total population, 61% were female; 84% of subjects were white, 10% black, 2% Asian, and 4% were of other racial/ethnic groups. The mean age of subjects was 33 years.
Solicited Adverse Events
Solicited local adverse reactions and systemic adverse events collected for 4 days (day of vaccination and the next 3 days) are presented in Table 2.
Table 2: FLULAVAL: Incidence of Solicited Local
Adverse Reactions and Systemic Adverse Events Within 4 Daysa of
Vaccination in Adults (Total Vaccinated Cohort)
|Percentage of Subjects Reporting Event|
|Study 1b 18 Through 64 Years of Age||Study 2b 50 Years of Age and Older||Study 3b 18 Through 49 Years of Age|
N = 721
N = 279
N = 610
N = 615
N = 3,783
N = 3,828
|Local Adverse Reactions|
|Systemic Adverse Events|
|Fever ≥ 99.5°F (37.5°C)||11||10||1||1||3||1|
|Total vaccinated cohort for safety included all
vaccinated subjects for whom safety data were available.
a 4 days included day of vaccination and the subsequent 3 days.
b Study 1: NCT01389479; Study 2: NCT00232947; Study 3: NCT00216242.
c US-licensed trivalent, inactivated influenza vaccine (manufactured by Sanofi Pasteur SA).
d For Study 2 and Study 3, includes muscle aches and arthralgia.
Unsolicited Adverse Events
The incidence of unsolicited adverse events in the 21 days post-vaccination was comparable for FLULAVAL and the active comparator in Study 1 (16% and 15%, respectively) and in Study 2 (18% and 21%, respectively). In Study 3, the incidence of unsolicited adverse events was comparable for the groups (21% for FLULAVAL and 19% for placebo).
Unsolicited adverse events defined as reported with FLULAVAL in > 1.0% of subjects are described as follows: Study 1: Cough, headache, and pharyngolaryngeal pain; Study 2: Diarrhea, headache, and nasopharyngitis; and Study 3: Pharyngolaryngeal pain, headache, fatigue, cough, injection site pain, upper respiratory tract infection, musculoskeletal pain, nasopharyngitis, injection site erythema, and discomfort.
Serious Adverse Events (SAEs)
In Study 1, no SAEs were reported. In Study 2, 3% of subjects receiving FLULAVAL and 3% of subjects receiving the active comparator reported SAEs. In Study 3, 1% of subjects receiving FLULAVAL and 1% of subjects receiving placebo reported SAEs. In the 3 clinical trials, the rates of SAEs were comparable between groups and none of the SAEs were considered related to vaccination.
FLULAVAL in Children
Study 4 (Immunogenicity Non-Inferiority)
An observerblind, active-controlled US study evaluated subjects 3 through 17 years of age who received FLULAVAL (N = 1,055) or FLUZONE (N = 1,061), a US-licensed trivalent, inactivated influenza vaccine, manufactured by Sanofi Pasteur SA. In the overall population, 53% were male; 78% of subjects were white, 12% were black, 2% were Asian, and 8% were of other racial/ethnic groups. The mean age of subjects was 8 years. Children 3 through 8 years of age with no history of influenza vaccination received 2 doses approximately 28 days apart. Children 3 through 8 years of age with a history of influenza vaccination and children 9 years of age and older received one dose. Solicited local adverse reactions and systemic adverse events were collected for 4 days (day of vaccination and the next 3 days) (Table 3).
Table 3: FLULAVAL: Incidence of Solicited Local
Adverse Reactions and Systemic Adverse Events Within 4 Daysa of First
Vaccination in Children 3 Through 17 Years of Total vaccinated cohort
for safety included all vaccinated subjects for whom safety data were available.
|FLULAVAL %||Active Comparatorc %|
|3 Through 17 Years of Age|
|Local Adverse Reactions||N = 1,042||N = 1,026|
|3 Through 4 Years of Age|
|Systemic Adverse Events||N = 293||N = 279|
|Loss of appetite||16||13|
|Fever ≥ 100.4°F (38.0°C)||5||3|
|5 Through 17 Years of Age|
|Systemic Adverse Events||N = 750||N = 747|
|Fever ≥ 100.4°F (38.0°C)||5||4|
|a 4 days included day of vaccination and the
subsequent 3 days.
b Study 4: NCT00980005.
c US-licensed trivalent, inactivated influenza vaccine (manufactured by Sanofi Pasteur SA).
In children who received a second dose of FLULAVAL or the comparator vaccine, the incidences of adverse events following the second dose were generally lower than those observed after the first dose.
The incidence of unsolicited adverse events that occurred within 28 days (day 0-27) of any vaccination reported in subjects who received FLULAVAL (N = 1,055) or FLUZONE (N = 1,061) was 40% and 37%, respectively. The unsolicited adverse events that occurred most frequently ( > 0.1% of subjects for FLULAVAL) and considered possibly related to vaccination included diarrhea, influenza-like illness, injection site hematoma, injection site rash, injection site warmth, rash, upper abdominal pain, and vomiting. The rates of SAEs were comparable between groups (0.9% and 0.6% for FLULAVAL and the comparator, respectively); none of the SAEs were considered related to vaccination.
In addition to reports in clinical trials, the following adverse events have been identified during postapproval use of FLULAVAL. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their incidence rate or establish a causal relationship to the vaccine. Adverse events described here are included because: a) they represent reactions which are known to occur following immunizations generally or influenza immunizations specifically; b) they are potentially serious; or c) the frequency of reporting.
Blood and Lymphatic System Disorders: Lymphadenopathy.
Eye Disorders: Eye pain, photophobia.
Gastrointestinal Disorders: Dysphagia.
Musculoskeletal and Connective Tissue Disorders: Muscle weakness, arthritis.
Nervous System Disorders: Dizziness, paresthesia, hypoesthesia, hypokinesia, tremor, somnolence, syncope, Guillain-Barre syndrome, convulsions/seizures, facial or cranial nerve paralysis, encephalopathy, limb paralysis.
Psychiatric Disorders: Insomnia.
Vascular Disorders: Flushing, pallor.
Read the entire FDA prescribing information for Flulaval (Influenza Virus Vaccine) »
Additional Flulaval Information
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