In an era where the world faces various pandemics, disease prevention through vaccination has become increasingly important, especially for influenza, a common infectious disease that can be more severe than expected. The nasal spray influenza vaccine, or Live Attenuated Influenza Vaccine (LAIV), is an interesting new option for those seeking convenience in vaccination, particularly children and those afraid of needles.
Get to know the nasal spray influenza vaccine in detail, from its mechanism of action, advantages, limitations, and important information that will help you make an appropriate choice of vaccine.
What is the nasal spray influenza vaccine?
The nasal spray influenza vaccine, or Live Attenuated Influenza Vaccine (LAIV), is a live attenuated vaccine administered by spraying through the nasal cavity instead of injection. It effectively prevents influenza in children and adolescents.
Effectiveness of the nasal spray influenza vaccine (FluMist Intranasal Vaccine)
- 88% is the rate of influenza prevention in children and adolescents (ages 2-17 years)
- 54.9% is the effectiveness in preventing influenza better than the inactivated injectable vaccine (TIV)
- 63% is the rate of reduction in hospitalization from influenza
Note: “Flu” comes from the influenza virus, and “Mist” means spray. Therefore, FluMist Intranasal Vaccine is a vaccine that uses a spray mist into the nose to stimulate the body to build immunity against the influenza virus.
Advantages of the nasal spray influenza vaccine (FluMist Intranasal Vaccine)
- Painless, no needle required Helps reduce fear or anxiety from injections, making it easier for needle-phobic individuals and young children to receive the vaccine.
- Increased acceptance Encourages children and adults to be more willing to get vaccinated.
- Short and convenient procedure Vaccination is simple, uncomplicated, and quick, requiring only a nasal spray administered by a doctor or healthcare professional.
- Affordable influenza vaccine Compared to its effectiveness and reduction in hospitalization rates.
- Stimulates targeted immunity This vaccine stimulates immunity in the mucous membranes of the upper respiratory tract, the main entry point of the influenza virus.
- Fast-acting Immunity develops within 3-5 days after spraying.
- Suitable for various age groups Can be used in children aged 2 years and older up to adults aged 49 years. It is recommended for ages 2-17 years to receive the vaccine.
- Long-lasting protection After receiving the nasal spray influenza vaccine, protection lasts up to 12 months, whereas injectable vaccines’ immunity begins to decline after 4-6 months.
- Helps prevent outbreaks Significantly reduces illness rates in communities, especially among children and adolescents.
- Safe The nasal spray influenza vaccine (FluMist Intranasal Vaccine) is FDA-approved and regulated by drug authorities in many countries and has been registered in Thailand. It is a spray-type vaccine designed as a Cold-Adapted Virus and Temperature Sensitive strain, meaning it only grows at low temperatures found in the nasal cavity or upper respiratory tract, making it safe and non-disease-causing when entering other parts of the body with higher temperatures.
Note: The nasal spray influenza vaccine is easy and convenient to use but must be prescribed and administered by a doctor or pediatrician. It cannot be self-administered.
Who is the nasal spray influenza vaccine (FluMist) suitable for?
- Children under 2 years old who fear needles or injections; parents can consider this as a good option for their children.
- Adolescents and adults up to 49 years old who are in good health.
Who should be cautious?
- Immunocompromised individuals, such as those with HIV infection, those on immunosuppressive drugs, and cancer patients.
- Children with asthma or a history of respiratory system issues in the past 12 months.
- Pregnant women.
- Those allergic to vaccine components or with a history of drug allergies.
However, always consult a doctor before vaccination to assess individual suitability.
Does the nasal spray influenza vaccine (FluMist) have side effects?
After receiving the nasal spray influenza vaccine, there are no severe side effects. Only common side effects that can occur with any vaccine, which usually resolve within a few days, such as:
- Low-grade fever, possibly headache.
- Mild fatigue.
- Mild muscle aches.
- Nasal congestion or runny nose.
- Coughing, sneezing, or throat irritation.
- Sore throat or hoarseness.
If severe symptoms occur, such as difficulty breathing or swelling (rare), seek medical attention immediately.
How is the nasal spray influenza vaccine different from the injectable vaccine?
Comparison between the nasal spray vaccine and the injectable vaccine is as follows:
Biological differences
- Nasal spray influenza vaccine uses live attenuated virus.
- Injectable influenza vaccine uses inactivated virus or viral components.
Vaccination procedure
- Nasal spray vaccine is sprayed into the nasal cavity.
- Injectable vaccine is injected into the muscle.
Effectiveness
- Both types have similar effectiveness in preventing influenza.
- The nasal spray vaccine is more effective in children.
Dosage for the nasal spray influenza vaccine
- Ages 2 – 8 years: Receive 1 or 2 doses of the nasal spray influenza vaccine. If 2 doses are given, each dose should be at least 1 month apart.
- Ages 9 years – adults up to 49 years: Receive 1 dose of the nasal spray influenza vaccine.
The Pediatric Infectious Diseases Society of Thailand and the Infectious Diseases Society of Thailand recommend annual influenza vaccination once per year.
Why should you get the influenza vaccine every year?
Influenza is not a simple disease as many think. It can cause severe symptoms and dangerous complications, especially in high-risk groups, including:
1. Health impacts
- High fever, fatigue, muscle pain.
- Respiratory tract inflammation.
- Pneumonia.
- Myocarditis (inflammation of the heart muscle).
- Encephalitis (inflammation of the brain).
2. Economic and social impacts
- Missed work/school days.
- Medical treatment costs.
- Transmission within families and communities.
3. Influenza virus constantly mutates
- The influenza virus continuously changes its structure.
- Mutations allow new viruses to evade old immunity.
- The circulating strains vary each year.
4. Immunity from the vaccine decreases over time
- Immunity from the vaccine wanes over time.
- After 6-8 months, the protective effect significantly decreases.
- Repeated vaccination can boost immunity strength.
5. Reduces disease severity
According to influenza severity statistics from the Department of Disease Control (DDC), Ministry of Public Health (MOPH), outbreaks occur annually. In 2024, there were 668,027 cumulative cases and 51 deaths, mostly elderly and those with underlying diseases.
High-risk groups with many cases include young children and school-aged children. Common strains are A/H1N1, A/H3N2, and B Victoria. The most important and effective prevention is to receive the influenza vaccine.
Nasal spray influenza vaccine, a good health choice
The nasal spray influenza vaccine is an interesting medical innovation and a good option for influenza prevention, especially for children and those afraid of needles. This vaccine has many advantages, including convenience, effectiveness in stimulating local immunity, and reducing pain from injections.
It is an effective and safe option, especially during the rainy and winter seasons, which are the epidemic seasons. Annual vaccination remains important due to the continuous mutation of the virus.
