H5N1 never went away - neither will H1N1 - it is a continuous threat

SHOOT: We need to guard against flu fatigue and cynicism and remain alert to this ever evolving danger.

TIMESONLINE: The danger from this particular virus is especially acute because it is new: our immune systems are naive to it, and this raises the likelihood that it will infect a very large number of people.

Swine flu could thus have severe effects even if it is not particularly lethal. Virologists are likening it to the strain that caused the 1968-69 pandemic, which was also considered mild: it killed about one in 1,000 of those it infected. Its novelty, however, meant that it infected more than a billion people worldwide, causing a million deaths. A virus with a similar virulence and attack rate would infect about 18 million people in Britain, and kill 18,000, three times as many as usually die from seasonal flu. The NHS would be stretched to its limits, so deaths from other causes would rise as well. The pandemic would be mild only by degree.

There is also no guarantee that this virus will continue to be comparatively benign. It is a fact of life that flu mutates fast, and there is every possibility that H1N1 will become more virulent, or resistant to antiviral drugs. The 1918-19 Spanish flu began as a mild virus in the northern hemisphere spring. It returned with a vengeance in the winter, bearing a mutation that enabled it to kill 50 million. If swine flu disappears over the summer, we can expect it back when the weather gets colder and wetter. It might well have turned nastier by then.

clipped from www.timesonline.co.uk For some media commentators H1N1 is just another scare, an unfounded panic like those that blew up over the MMR vaccine and avian flu. It may help editors to shift newspapers, scientists to win grants, public health officials to justify their existence and pharmaceutical companies to sell antivirals, but they are doing so by “manipulating fright”. Most health scares are indeed groundless, and some, such as MMR, have caused grave damage to public health. Swine flu, however, is not one of them. It is a threat that must be taken extremely seriously, even if the death toll does not rise sharply in the next few weeks. While scientists are describing swine flu as a mild strain, this terminology is relative. There is no such thing as mild flu - it is always a serious infection that can be life-threatening.