As many as 340,856 suspected H3N2 cases have been reported in Pakistan, of which 12 per cent samples tested positive, National Institute of Health (NIH), said on Tuesday.

The elderly, pregnant women, children and patients with chronic diseases are at higher risk.

The NIH advisory states that in the 2025-26 season, the influenza H3N2A subclade has emerged globally. Since August 2025, H3N2 cases have been increasing rapidly in different global regions.

Vaccination is the most effective means of preventing influenza.

The advisory states that hand hygiene, coughing and sneezing precautions, and avoiding crowds are essential.

The NIH has issued an advisory in view of the increasing threat of seasonal influenza H3N2. In the 2025/26 season, influenza A(H3N2) subclade K has emerged globally.

According to the NIH, a sharp increase in H3N2 cases was reported in various global regions since August 2025.

There was a significant increase in influenza cases in South Asia from May to November 2025, where 66% of the cases were H3N2.

Significant cases of H3N2 have also been reported in Australia and New Zealand. According to the advisory, an increase in ILI and SARI cases was observed in Pakistan, with 340,856 suspected cases reported during weeks 44 to 49. 12% of the samples tested were found to be H3N2 positive.