Influenza Virus Vaccine, Live Attenuated
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. Vaccination remains the most effective method for preventing influenza and its complications. This article provides comprehensive information about the Live Attenuated Influenza Vaccine (LAIV).
Uses & Indications
The Live Attenuated Influenza Vaccine (LAIV), often referred to as the nasal spray flu vaccine, is designed to protect against seasonal influenza. It is approved for use in healthy, non-pregnant individuals aged 2 through 49 years. LAIV is intended to prevent influenza illness caused by the specific influenza virus strains included in the vaccine for the current flu season. It can help reduce the severity of illness in individuals who get vaccinated but still become infected.
How It Works
LAIV contains weakened (attenuated) live influenza viruses that replicate in the nasal passages, stimulating an immune response without causing significant illness. This immune response creates antibodies that protect against future infection by the same or similar influenza virus strains. Because LAIV contains live viruses, it mimics a natural infection more closely than inactivated influenza vaccines, potentially offering broader immune protection.
Dosage and Administration
LAIV is administered intranasally, meaning it is sprayed into the nostrils. The typical dose is 0.2 mL divided equally between the two nostrils. Only healthcare professionals should administer LAIV. The vaccine is usually given as a single dose annually, typically during the fall or early winter, before the peak flu season.
Side Effects
Like any vaccine, LAIV can cause side effects. Common side effects are generally mild and may include runny nose, nasal congestion, sore throat, cough, and mild headache. In children, minor side effects may also include fever, irritability, vomiting, and muscle aches. These side effects generally resolve within a few days. Serious side effects are rare.
Warnings and Precautions
LAIV should not be administered to certain individuals, including:
Pregnant women
Children younger than 2 years of age
Adults 50 years of age and older
Individuals with weakened immune systems (due to illness or medications)
People with a history of severe allergic reaction to any component of the vaccine or a previous dose of any influenza vaccine
Children and adolescents (2 through 17 years of age) receiving aspirin or salicylate-containing medications
* Individuals with certain chronic health conditions such as asthma, chronic lung disease, or heart disease should consult their healthcare provider before receiving LAIV.
Drug Interactions
Certain medications may interact with LAIV. Individuals taking immunosuppressants or antiviral medications should discuss these with their healthcare provider before receiving the vaccine.
FAQs
Q: How effective is the Live Attenuated Influenza Vaccine?
A: The effectiveness of LAIV can vary from season to season depending on the match between the vaccine strains and the circulating influenza viruses.
Q: Can I get the flu from the nasal spray vaccine?
A: Because LAIV contains weakened live viruses, it is possible to experience mild flu-like symptoms after vaccination. However, these symptoms are typically less severe than actual influenza.
Q: Who should not receive the nasal spray vaccine?
A: Certain groups, including pregnant women, children under 2, adults over 49, and individuals with certain health conditions, should not receive LAIV. Consult a healthcare professional for specific guidance.
Q: Can I receive LAIV if I am allergic to eggs?
A: Egg allergy is not a contraindication for LAIV.
Q: What should I do if I experience side effects after receiving LAIV?
A: Mild side effects are common and usually resolve within a few days. Contact your healthcare provider if you experience severe or concerning side effects.
This information is for educational purposes only and is not a substitute for professional medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
