H3N2 Wisconsin

The H3N2 influenza virus is a subtype of the Influenza A virus, which is known for causing seasonal flu outbreaks in humans. The specific strain, A/Wisconsin/67/05 (H3N2), was isolated in 2005 from a human patient in Wisconsin . This strain has been extensively studied and used in vaccine development due to its significant role in respiratory disease research .

The H3N2 virus is characterized by its hemagglutinin (HA) and neuraminidase (NA) surface proteins. These proteins are crucial for the virus’s ability to infect host cells and for the immune system’s recognition of the virus. The HA protein, in particular, has several antigenic sites that are targeted by antibodies. Over time, the virus undergoes antigenic drift, leading to changes in these sites and necessitating updates to the influenza vaccine .

Research has shown that the immunodominance of antigenic sites on the HA protein can vary. For the H3N2 strain A/Wisconsin/67/05, studies have demonstrated that antigenic site B is more immunodominant compared to site A . This finding is significant for vaccine development, as it helps in predicting future antigenic drift and selecting appropriate vaccine strains .

The recombinant H3N2 virus, such as the A/Wisconsin/67/05 strain, is often used in research and vaccine production. Recombinant viruses are created by inserting specific genes from one virus into another, allowing for the study of particular viral components in isolation. This approach is valuable for understanding the virus’s behavior and for developing targeted vaccines .

Recent studies have identified human monoclonal antibodies that are highly cross-reactive and protective against various H3N2 strains, including A/Wisconsin/67/05 . These antibodies target conserved regions of the HA and NA proteins, providing broad protection and highlighting the potential for developing universal influenza vaccines .