H3N2 Wisconsin/67/05

The H3N2 Influenza-A Virus Wisconsin/67/05 is a subtype of the Influenza A virus, which is known for causing seasonal flu outbreaks in humans. This particular strain, identified in Wisconsin in 2005, has been a significant focus of research due to its impact on public health and its role in the evolution of influenza viruses.

The H3N2 subtype evolved from the H2N2 subtype through a process known as antigenic shift, where genes from multiple subtypes reassorted to form a new virus . This process allows the virus to evade the immune system, leading to new outbreaks. The H3N2 strain has been dominant in various flu seasons, often outcompeting other subtypes like H1N1 and H1N2 .

The H3N2 Influenza-A Virus Wisconsin/67/05 strain was included in the 2006-2007 influenza vaccine for the northern hemisphere due to its prevalence and impact . The strain’s genetic makeup includes specific changes at antigenic sites, which are regions of the virus recognized by the immune system .

H3N2 has been responsible for several significant flu outbreaks, including the Hong Kong Flu pandemic of 1968-1969, which resulted in up to 750,000 deaths . The Wisconsin/67/05 strain contributed to the seasonal flu outbreaks in the mid-2000s, highlighting the importance of continuous monitoring and vaccine updates.

Research on the H3N2 Influenza-A Virus Wisconsin/67/05 has been crucial for understanding the evolution and spread of influenza viruses. Studies have shown that the virus undergoes frequent genetic changes, particularly in the hemagglutinin (HA) protein, which is a key target for the immune response . These changes necessitate regular updates to the flu vaccine to ensure its effectiveness.

The strain has been propagated in specific pathogen-free (SPF) chicken embryonated eggs for research purposes, aiding in the development of vaccines and antiviral treatments . The continuous study of this strain and others like it helps predict future flu seasons and improve public health responses.