Flu Vaccines Struggle to Combat Emerging Strains in US
Health officials report the flu vaccine had one of its worst effectiveness rates in over a decade, as a new strain that dominated early winter was not well matched to the vaccine.
As the flu season winds down across the United States, health officials have revealed that the flu vaccine did not perform as well as hoped, with one of the worst effectiveness rates seen in more than a decade. The culprit appears to be a new strain of the influenza virus that emerged and dominated the early winter period, but was not well-matched to the composition of the vaccine.
Vaccine Struggles to Keep Up with Evolving Flu Strains
Each year, health experts carefully analyze the circulating flu strains and attempt to formulate a vaccine that will provide the best protection against the most likely dominant viruses. However, the rapid evolution of the influenza virus can sometimes outpace these efforts, leading to a mismatch between the vaccine and the strains that end up spreading widely.
This appears to be the case for the 2022-2023 flu season, where a new variant of the H3N2 influenza A virus, known as XBB.1.5, became the dominant strain early on. The current flu vaccine was not as effective against this emerging strain, resulting in one of the poorest vaccine effectiveness rates in recent memory.
{{IMAGE_PLACEHOLDER}}Source: Associated Press
