Recent years have revealed new challenges in managing influenza in India. The winter of 2024-2025 saw an unusually severe outbreak of influenza B, followed by a surge of the H3N2 strain in the post-monsoon season. These events exposed gaps in the current vaccination strategy. India’s influenza burden is but often underestimated. The existing single annual flu vaccine does not adequately protect the population through both peak seasons. This has prompted calls for a revised approach to vaccination policy.
Influenza Burden and Strain Variability
Influenza causes serious respiratory illness and deaths worldwide, especially in vulnerable groups. In India, influenza peaks twice yearly—during winter (January to March) and post-monsoon (July to September). Multiple virus strains circulate simultaneously, including H1N1, H3N2, and influenza B. Each strain varies in severity and vaccine response. Recent outbreaks showed influenza B causing unexpectedly severe illness and H3N2 driving fresh infections.
Limitations of Current Vaccines
India uses two main vaccine types – inactivated injectable vaccines and live attenuated nasal sprays. Both reduce risk but vary in effectiveness by strain and age. Protection is strongest against H1N1, moderate for influenza B, and weakest for H3N2. Flu viruses mutate constantly through antigenic drift, requiring annual vaccine updates. Unlike vaccines for diseases like polio, flu vaccines provide only short-term immunity. Protection peaks weeks after vaccination but wanes within three to six months.
Challenges of Single Annual Vaccination
The short duration of vaccine-induced immunity conflicts with India’s dual influenza seasons. A single annual dose cannot cover both peaks effectively. For example, a vaccine given before the monsoon protects through September but not the winter wave. Conversely, a winter dose fails to protect during the post-monsoon peak. This leaves large population segments vulnerable for nearly half the year. Countries with one flu season do not face this problem as acutely.
Proposal for Biannual Vaccination
A biannual vaccination schedule could better suit India’s epidemiology. Two doses yearly—one before the monsoon and one before winter—would maintain immunity across both peaks. This approach could reduce cases, hospitalisations, and deaths , especially among children who bear the highest burden. Although two doses may seem demanding, the health benefits justify the effort.
Policy and Public Awareness Issues
Despite vaccine availability for over a decade, less than 5% of Indians receive influenza vaccines. Low uptake stems from perceptions of flu as minor, limited awareness, and lack of government policy support. Influenza vaccines are not part of India’s Universal Immunisation Program and remain in the private sector. Including biannual vaccination in the UIP could improve access and affordability. Coupled with awareness campaigns, this could normalise flu vaccination and reduce disease burden.
Vaccine Production and Accessibility
India’s strong domestic vaccine manufacturing capacity can support expanded influenza vaccination. Government backing could lower costs and ensure supply for biannual doses. This would help reach vulnerable populations and improve overall public health outcomes.
Questions for UPSC:
- Critically discuss the challenges of influenza vaccination in countries with multiple seasonal peaks like India and analyse potential policy solutions.
- Examine the impact of antigenic drift on vaccine development and effectiveness, and estimate its implications for public health strategies.
- Point out the factors influencing vaccine acceptance in India and discuss how government policy and public awareness can improve immunisation coverage.
- Analyse the role of domestic vaccine production capacity in strengthening national immunisation programmes and suggest measures to enhance vaccine accessibility.
