Past exposure to other variants of H1N1 may be protective, the CDC says. May 21, 2009— -- Older adults might have some pre-existing immunity to H1N1 swine flu, according to the U.S. Centers ...

An H2N2 virus causes the “Asian” flu pandemic, completely displacing the H1N1 viruses that have been circulating in humans since 1918. The pandemic is fairly mild, killing 1 to 1.5 million ...

Also like the 1918 strain, H2N2 viruses have not circulated in humans for several decades, but continue to do so among birds and swine 8. The oldest human H2N2 strains are closely related to avian ...

When the pandemic was over the H2N2 vaccination programme was stopped in the late 1960s, although the virus is still present today among birds and swine. Vulnerability of Youth ...

H1N1, which was responsible for the 1918 pandemic virus and the recent swine flu pandemic, H2N2, the 1957 Asian flu pandemic strain, and the H3N2 Hong Kong pandemic strain in 1968, which displaced ...

The diagram shows the important events and processes in the emergence of influenza A (H1N1) viruses during the past 91 years. Avian, swine, and human populations are represented in the top, middle ...

H2N2 caused a pandemic in 1957, killing a few million people. This strain swapped two of its genes with another bird flu strain to produce H3N2, a grandchild of H1N1 that went pandemic in 1968 ...

In August 1957, the "Asian flu" was exactly where "swine-origin influenza A (H1N1)" is today. A new, ... Scientists soon determined it was a radically new strain of the H2N2 class of influenza.

Governments should launch a vaccination programme now to guard against a possible H2N2 flu pandemic, according to an article in the journal Nature.

Governments should launch a vaccination programme now to guard against a possible H2N2 flu pandemic, according to an article in the journal Nature.

Governments should launch a vaccination programme now to guard against a possible H2N2 flu pandemic, according to an article in the journal Nature., external. The US authors say immunity to the ...