Dr Angus Nicoll and Dr Marc Spenger said: ‘It seems increasingly unlikely that the 2009-10 pandemic will follow the pattern of the last (1968) pandemic in Europe when transmissibility increased for the second winter’.
There are two important differences between the swine flu (H1N1) pandemic and the 1968 pandemic, they point out.
‘First, many people in their late fifties and older currently have natural immunity from exposure to a similar earlier influenza A(H1N1) virus circulating before the 1957 pandemic,’ they said. ‘Second, there have been unprecedented influenza vaccination campaigns in some European countries, increasing the population protected beyond those who acquired natural immunity when they became ill during the pandemic.’
Drs Nicoll and Spenger conclude that flu in Europe in the 2010-11 winter is likely to be similar to the pattern currently being seen in the southern hemisphere.
‘However,’ they add ‘those predictions will need to be checked and confirmed or refuted. This can only be done by networks of laboratories at local, national and international level so that new virus variants can be detected in a timely manner.’