The case to rethink India’s influenza vaccination strategy, Pg13

Key Highlights:

• Influenza causes significant respiratory illness, hospitalizations, and deaths worldwide, especially among vulnerable populations.
• India experiences two distinct influenza peaks: winter (January-March) and post-monsoon (July-September).
• Current influenza vaccines offer limited protection, typically strongest against H1N1, moderate against influenza B, and weakest against H3N2.
• Vaccine effectiveness declines significantly within 3-6 months, posing a challenge for India's dual influenza seasons.
• Less than 5% of Indians receive flu vaccines due to perceptions, limited awareness, and lack of government support.

Detailed Insights:

• India's influenza burden is often underestimated, with official focus primarily on the H1N1 strain, despite outbreaks of other strains like influenza B and H3N2.
• Antigenic drift in influenza viruses necessitates regular vaccine updates, unlike vaccines for diseases like measles or polio that provide long-lasting immunity.
• Inactivated influenza vaccines (injection) and live attenuated vaccines (nasal spray) are available in India, but their effectiveness varies by strain and age.
• Biannual influenza vaccination (May/June and November/December) could provide more consistent protection across both peaks in India.
• Inclusion of influenza vaccines in the Universal Immunisation Program (UIP) could improve affordability, accessibility, and public awareness.

Key Concepts Involved:

• Antigenic Drift: Genetic changes in viruses that allow them to evade immune defenses.
• Inactivated Influenza Vaccine: A vaccine containing non-live influenza viruses, administered via injection.
• Live Attenuated Vaccine: A vaccine containing weakened live influenza viruses, administered as a nasal spray.
• Universal Immunisation Program (UIP): A government program providing free vaccines against life-threatening diseases.