ICMR confirms no new H1N1 strain in India surge

The Indian Council of Medical Research has confirmed that a recent surge in influenza cases across the country is being driven by a circulating H1N1 strain that has been present since 2025, with no new strain detected. The clarification comes as health authorities monitor a significant rise in infections, particularly in Delhi, and emphasize that the current virus is well matched to available vaccines.

According to ICMR scientists, the circulating virus is the H1N1 pdm09 strain, specifically belonging to clade 6B.1A.5a2a and subclade D.3.1.1. This strain has been in circulation since 2025 and closely matches the AMissouri112025 H1N1 pdm09-like virus. Officials stated that continuous genomic and virological surveillance has not identified any novel mutations, and the strain is well matched with the vaccine strains recommended for the Northern Hemisphere. The agency emphasized that seasonal influenza, including H1N1, is mostly self-limiting, with common symptoms like fever, cough, headache, and body aches typically resolving with appropriate care and rest.

The clarification follows a high-level review meeting chaired by Union Health Minister J.P. Nadda on August 22, 2026. Delhi...