Analysis: Some protection is in place – but impact of this virus is impossible to predict

Published on Sunday 26 April 2009 22:40

IT IS still too early to say whether this is going to be a worldwide event or an event limited to a few countries. Even if it does go global, we do not know how serious it will be.

The facts are still on the short side but one fact that is clear is that this virus is a mixture of human, swine and avian-type genes. Because it is a new virus, it is difficult to predict what it is going to do as we have not had any experience of it before.

It will now be important to confirm exactly how many of these people who have died in Mexico died of swine flu. That is still be investigated and is important because it will help us tell if it is a nasty virus or whether something else, along with the flu, has contributed to these deaths. The cases seen in the US have been mild flu, picked up almost retrospectively.

Previously, this virus has generally infected people who have been in close contact with pigs, with some limited evidence that it can spread from person to person. However, when it has done this it has not gone any further than close family contacts.

With these latest cases to emerge, the worst case scenario is that it turns out to be a nasty virus that will go on to kill many more people, as it is doing in Mexico. It could also kill those who are not the usual victims of flu, who are normally the vulnerable and elderly groups. It could kill the fit and healthy as well as it did with the pandemic in 1918. Then it could quickly spread around the world. If this is a pandemic strain, it would not take that long to reach the UK.

Another possibility is that we have a pandemic virus which is quite mild and does not kill as many people as some of the worst pandemics we have seen.

The best we can hope for is that this outbreak just fizzles out.

There is currently no vaccine which would protect against the strain of flu seen in the cases in Mexico. They will probably be developing a seed vaccine virus, but the decision to roll this out to full production has yet to be made. To develop a vaccine to be used on large number of people, and to test its safety, can take a long time.

All of the attention that has been paid to the H5N1 strain of flu in birds has meant that we now have better protection in the case of a pandemic than we did in the past.

We have developed the infrastructure to cope with a pandemic and what to advise the public and doctors. We have also stockpiled anti-viral drugs to treat people with flu or at risk of infection.

I think we are as well prepared as we can be, though there are still questions about how that protection will work. We have never, obviously, tried the plans in practice.

The best we can advise people at the moment is to carry on as usual while we observe what happens with this virus. At the moment it is too early to say if there is going to be a real problem or not. What we should be doing is keeping ourselves informed of what is happening. More advice will be released in the coming days and we should be watching this carefully.

&#149 Professor Hugh Pennington is a microbiologist and emeritus professor at Aberdeen University.