Epidemiological features of a new strain of the influenza A virus--influenza A (H1N2) circulating in England and its public health implications

The UK influenza season of 2001/2002 was characterized by widespread geographic circulation of a new subtype of influenza A (H1N2) virus throughout the duration of the season. Younger children were predominantly infected, suggesting primary infection. Despite this, the public health impact of this new virus was minimal. It remains to be seen whether influenza A (H1N2) virus will persist and co-circulate with the previously circulating subtypes of influenza A (H1N1 and H3N2), or whether it was a sporadic recombination event that will disappear. Ultimately, the emergence of a new strain highlights the importance of continual surveillance of circulating viruses.