First time flu infection may affect lifetime immunity

Conclusion This modelling study shows how the strains of influenza A – "bird flu" – circulating when a person is born give them lifelong protection against new subtypes with the same H protein groups. The researchers call this immune imprinting. This may help to explain the high severity and mortality rate seen among certain groups. For example, the massive flu pandemic of 1918 was an H1N1 strain. This had a very high fatality rate among young adults, which the researchers consider may have been because when they were born (between 1880 and 1900), H3 was the dominant strain. Therefore they had no protection when encountering H1. However, elderly adults of the same generation did have protection when H3 peaked in 1968. These observations, however, aren't really too unexpected. It's already well known that the flu virus has many different strains; which is why people catch flu several times in their life, and why it's difficult to say the flu vaccine will definitely stop you catching flu (vaccines only cover the strain expected to be circulating that season). We also know that exposure to a specific virus gives us protection against the same if we encounter it again. So in that sense this isn't really "news" as such. Nevertheless, as the researchers say, their findings could help in planning for future flu outbreaks, in knowing which age groups may be most at risk. Though these are only modelling estimates so it's difficult to give certain answers. As th...
Source: NHS News Feed - Category: Consumer Health News Tags: Heart/lungs Medical practice Source Type: news