Influenza Virus Vaccine, Live Attenuated
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. The influenza virus vaccine, live attenuated, is a vaccine designed to protect against seasonal influenza. This article provides a comprehensive overview of this specific type of flu vaccine.
Uses & Indications
The live attenuated influenza virus vaccine (LAIV) is indicated for the prevention of influenza disease caused by influenza A and B viruses contained in the vaccine. It is approved for use in non-pregnant individuals, typically between the ages of 2 and 49 years, depending on the specific formulation and regulatory approvals in different regions. LAIV is not appropriate for individuals with certain medical conditions (see Warnings and Precautions). Always consult with a healthcare provider to determine if LAIV is the right choice for you.
How It Works
The influenza virus vaccine, live attenuated, works by introducing weakened (attenuated) live influenza viruses into the nasal passages. These weakened viruses are capable of replicating, but they do not cause severe illness. This replication stimulates the immune system to produce antibodies against the influenza viruses contained in the vaccine. These antibodies provide protection against influenza infection if the individual is exposed to circulating strains of the virus that match the vaccine components. Since the viruses are live, they mimic a natural infection, potentially providing broader and longer-lasting immunity compared to inactivated vaccines, although this can vary.
Dosage and Administration
The influenza virus vaccine, live attenuated, is administered intranasally (via a nasal spray) in two doses for individuals who have not previously received LAIV. The doses are typically given approximately four weeks apart. For those who have previously received LAIV, a single dose is usually sufficient. The dosage and administration schedule may vary depending on the specific vaccine formulation and the age of the recipient. Always follow the instructions provided by the healthcare provider.
Side Effects
Like all medications, the influenza virus vaccine, live attenuated, can cause side effects. Common side effects are generally mild and may include runny nose, nasal congestion, sore throat, cough, headache, muscle aches, and low-grade fever. More serious side effects are rare. It is crucial to discuss any concerns about side effects with your healthcare provider.
Warnings and Precautions
The influenza virus vaccine, live attenuated, should not be administered to certain individuals, including:
Children younger than two years old
Adults 50 years and older
Pregnant women
Individuals with weakened immune systems (e.g., due to HIV/AIDS, cancer, or immunosuppressive medications)
Individuals with chronic medical conditions such as asthma, heart disease, or lung disease
Individuals with a history of Guillain-Barré syndrome
Individuals with a known allergy to any component of the vaccine
Individuals with close contact with severely immunocompromised persons requiring a protected environment may need to avoid contact with those individuals for a period of time after receiving LAIV.
Drug Interactions
Certain medications, such as aspirin or salicylates, should be used cautiously with LAIV, especially in children and teenagers. Inform your healthcare provider about all medications you are taking, including over-the-counter medications and supplements. Antiviral medications can interfere with the effectiveness of LAIV and should not be taken within two weeks before or 48 hours after vaccination unless specifically directed by a healthcare provider.
FAQs
How effective is the live attenuated influenza vaccine? The effectiveness of LAIV can vary from season to season depending on the match between the vaccine strains and the circulating influenza viruses.
Can I get the flu from the live attenuated vaccine? No, the viruses in LAIV are weakened and cannot cause influenza. However, you may experience mild side effects that resemble flu symptoms.
Who should I contact if I experience side effects after receiving the vaccine? Contact your healthcare provider if you experience any side effects that concern you.
Is the live attenuated vaccine safer than the inactivated vaccine? Both types of influenza vaccines are considered safe; however, each has its specific benefits and risks. Consult your healthcare provider to determine the best option for you.
Where can I get the live attenuated influenza vaccine? LAIV is typically available at doctor’s offices, clinics, and pharmacies.
