H3N2 influenza

March 16, 2023

Recently, the Health Ministry confirmed that at least two people have succumbed to the H3N2 subtype of seasonal influenza in India.

About H3N2 influenza:  

  • Influenza A H3N2 is a seasonal virus and the occurrence of influenza infections normally peaks during season changes.
  • Symptoms- Fever, body ache, sore throat, cough, runny/blocked nose and a few shortness of breath.
  • It can spread from person to person and while anyone can get infected- older, adults and younger children are at a higher risk from H3N2.
  • The method of testing for H3N2 is also similar to COVID-19 testing – RTPCR.
  • There is a vaccine for seasonal flu that also covers H3N2.

Seasonal influenza:

  • According to WHO, seasonal influenza is an acute respiratory infection caused by influenza viruses.
  • There are 4 types of seasonal influenza viruses, types - A, B, C and D. In which Influenza viruses A, B, and C can infect humans.
  • Influenza A viruses are further classified into subtypes according to the combinations of the hemagglutinin (HA) and the neuraminidase (NA), the proteins on the surface of the virus.
  • There are 18 different subtypes of HA, which are numbered H1 through H18. Similarly, there are 11 different subtypes of NA, numbered N1 through N11.