ALBUQUERQUE, N.M. — Flu activity is increasing earlier than normal in parts of the western United States, with health officials reporting infection levels typically not seen until the middle of winter.
According to the Centers for Disease Control and Prevention, more than 1 million Americans have already contracted influenza this season. Nearly 99% of reported cases are linked to the H1N1 influenza virus.
Health experts say the current H1N1 strain has undergone genetic changes since this year’s flu vaccine was developed. Researchers believe those mutations may be contributing to the unusually early increase in cases and could affect how well existing immunity protects against infection.
Despite the changes, medical experts say this season’s flu vaccine still targets the H1N1 virus and is expected to provide protection, particularly against severe illness and hospitalization.
The early increase in flu activity has been most noticeable on the West Coast, where case levels have already reached numbers more commonly seen in January.
Public health officials continue to monitor flu trends as the respiratory virus season progresses and evaluate how the circulating strain behaves throughout the winter months.
