US FDA clears nasal flu vaccine: How safe and effective will it be?

How does the nasal spray influenza vaccine work?

Unlike injectable flu vaccines containing inactivated viruses, the nasal spray vaccine has a weakened form of live influenza virus strains to stimulate an immune response. This immune response provides protection against future influenza infections.

The nasal spray delivers the vaccine directly to the mucosal lining of the nasal passages, where influenza viruses typically enter the body.

You need a prescription to get it and though you can spray your nasal cavity with it, you can take the help of a healthcare worker or a caregiver who is 18 years of age or older.

Why is a nasal spray vaccine a breakthrough?

According to Dr Suranjt Chatterjee, senior consultant, internal medicine, Indraprastha Apollo Hospitals, nasal spray vaccine for home use is a significant breakthrough in flu prevention because it eliminates the need for injections. Its convenience and ease of use help those with needle anxiety, he adds.

“It provides mucosal immunity by protecting the nasal mucosa from infection, systemic immunity by producing antibodies to neutralize the virus and cellular immunity by eliminating infected cells. The nasal spray offers advantages over traditional injectable vaccines by targeting the primary site of influenza infection, providing broader protection against variant strains. It may offer longer-lasting immunity,” he says.

It is accessible to people with busy schedules or those living in areas with limited healthcare services. Additionally, FluMist can be stored at refrigerator temperatures, simplifying distribution and storage logistics.

What are the potential side effects?

Common side effects include nasal congestion, sore throat, headache, fatigue and cough. Individuals with certain medical conditions, such as asthma or weakened immune systems, should consult their healthcare provider before using the spray vaccine.

Can it help Indians?

Dr Chatterjee says a nasal vaccine can benefit Indians, particularly in rural areas where access to healthcare services is limited. Its ease of administration and storage makes it an ideal option for mass vaccination campaigns. However, factors such as cost, availability, and regulatory approvals need to be considered before FluMist can be introduced in India.

Is this vaccine going to be available in India?

Not as of now. This applies to only the US market. Dr Chatterjee says a nasal spray vaccine, when it does come to India, can help in community vaccinations. Its ease of administration and storage makes it an ideal option. However, factors such as cost, availability, and regulatory approvals need to be considered.