H3N2 Panama

The H3N2 Influenza-A Virus Panama/2007/99 is a strain of the influenza virus that has been significant in the study of influenza epidemiology and vaccine development. This strain is part of the H3N2 subtype of the Influenza A virus, which has been known to cause seasonal flu outbreaks in humans.

The H3N2 subtype emerged from an antigenic shift, a process where genes from multiple subtypes reassort to form a new virus. This particular strain, A/Panama/2007/99, was collected in 1999 and has been a subject of various studies due to its unique genetic makeup and its role in the evolution of influenza viruses .

The H3N2 strain descended from the H2N2 strain through antigenic shift, incorporating genes from avian influenza viruses. This genetic reassortment has allowed the H3N2 subtype to dominate over other influenza subtypes such as H1N1 and H1N2 .

The H3N2 Influenza-A Virus Panama/2007/99 has been prevalent in various regions and has contributed to significant influenza outbreaks. Studies have shown that this strain, along with others, has led to the development of cross-reactive antibodies in the population. For instance, a study conducted in Israel found that a significant percentage of children and adults had antibodies that recognized both A/Panama/2007/99 and other related strains .

One of the critical aspects of the H3N2 Influenza-A Virus Panama/2007/99 is its role in antigenic drift, a process where the virus undergoes small genetic changes over time. This drift can lead to the emergence of new strains that may evade the immune system, making it challenging to develop effective vaccines.

The presence of naturally occurring cross-reactive antibodies in a significant percentage of the population has important implications for the development of a universal influenza vaccine. Understanding the genetic and antigenic characteristics of strains like A/Panama/2007/99 is crucial for predicting future strains and improving vaccine composition .