Nasal Spray Flu Vaccine (LAIV)

     As influenza spreads heavily every year, even breathing can lead to infection, causing more severe symptoms than the common cold. Ramkhamhaeng Hospital offers a new alternative covering many age groups and needs. The Nasal Spray Flu Vaccine (LAIV) is the answer to “fear of needles” and other delicate limitations to reduce health risks.

What is the Nasal Spray Flu Vaccine?

     Nasal Spray Flu Vaccine or Live Attenuated Influenza Vaccine (LAIV) is a vaccine made from weakened viruses that cannot cause disease. The virus is designed to grow only at the lower temperatures of the nasal cavity but cannot grow in the lungs or other parts of the body where temperatures are higher, ensuring high safety.

Who is it suitable for?

     The nasal spray vaccine is approved for healthy individuals aged 2 to 49 years. It is particularly beneficial for children and teenagers, who have high transmission rates. Vaccinating this group effectively reduces community outbreaks.

Precautions: Who should NOT receive the nasal spray?

While convenient, there are limitations for certain groups:

• Children under 2 years and adults aged 50 and older.
• Pregnant women (though breastfeeding women can receive it).
• Individuals with weakened immune systems or those in close contact with severely immunocompromised patients.
• Individuals with a history of severe allergic reactions to any vaccine component.
• Children aged 2–17 years who regularly take aspirin-containing medications.
• Individuals with chronic underlying diseases (heart, lungs, kidneys, or diabetes) should consult a doctor first due to insufficient safety data for these groups.

Advantages of the Nasal Spray Flu Vaccine

The nasal spray flu vaccine has been used worldwide for over 20 years with more than 200 million doses administered. Benefits include:

• Long-lasting Immunity: Studies show immunity from the nasal spray lasts up to 1 year, while the injectable version begins to decline after 4–6 months.
• Mimics Natural Infection: Stimulates local immunity in the respiratory lining (IgA), acting as the first line of defense to trap germs.
• Reduces Hospitalization: Reduces hospitalization rates by up to 63% compared to unvaccinated individuals.

Dosage and Administration

The vaccine is sprayed into both nostrils, 0.1 ml per side (total 0.2 ml per dose). The schedule is as follows:

• Children aged 2–8 years: Receive 1 or 2 doses (depending on prior vaccination history). If 2 doses are required, they must be spaced at least 1 month apart.
• Ages 9–49 years: Receive only 1 dose per year.

Possible Side Effects

     Mild symptoms may occur and will resolve on their own shortly, such as runny nose, nasal congestion, low-grade fever, headache, or muscle aches.