H3N2 is a strain of influenza virus that can cause illness in humans. It is one of the three main types of influenza virus that cause seasonal flu outbreaks each year. H3N2 is a particularly virulent strain of the virus and can cause severe illness, especially in vulnerable populations such as the elderly, young children, and people with underlying health conditions.

The impact of H3N2 on public health can be significant. The virus can spread rapidly and cause large outbreaks, leading to high rates of hospitalisation and death. In some years, H3N2 has been associated with more severe flu seasons, and outbreaks have been reported in many countries around the world.

The impact of H3N2 on public health can be measured in several ways. One key measure is the number of cases and deaths attributed to the virus each year. According to the World Health Organization (WHO), influenza causes an estimated 3-5 million cases of severe illness and 290,000-650,000 deaths worldwide each year. While H3N2 is just one strain of influenza, it is a significant contributor to these numbers.

Another way to measure the impact of H3N2 is to look at the economic costs associated with the virus. These costs can include the direct costs of medical care and hospitalization, as well as the indirect costs of lost productivity and absenteeism. 

Prevention and control measures are critical in reducing the impact of H3N2 on public health. These measures can include vaccination, hand hygiene, and social distancing. Vaccination is the most effective way to prevent influenza, and annual flu shots are recommended for everyone over the age of six months. Other preventive measures, such as hand washing and avoiding close contact with sick individuals, can also help reduce the spread of the virus.