Friday, June 26, 2009

Radical shift in antiviral use considered


Let's start with antivirals. At present, everyone in the UK who is suspected of having H1N1 swine flu is offered them. But the virus is proving so mild that it has got health officials wondering whether this really is a sensible policy.

The Department of Health, like global health bodies, was expecting the next pandemic to be a more aggressive virus with a higher mortality rate.

There are plenty of antivirals to go round - enough Tamiflu (and the lesser-known Relenza) for half the population, and eventually for eight in ten people in the UK. Sir Liam Donaldson said that he'd asked scientists to look into the issue. "People with seasonal flu don't get antivirals," he said. "Should we be treating only those who are at higher risk of complications?"
It would represent a big shift in policy on Tamiflu. Already, some of those offered the drug are turning it down because they don't see the point in taking it when they have only mild symptoms or are simply a close contact of someone infected, or because they want to avoid possible side-effects like nausea.

But before people say that the whole pandemic issue has been a lot of fuss over very little, a word of caution. Sir Liam pointed out that they were working on the basis of three potential scenarios for this autumn and winter:

(1) the virus is largely unchanged and remains mild;
(2) it changes and becomes more severe (bear in mind that all flu viruses mutate, which is why we need a new seasonal flu vaccine each winter);
(3) (and the least likely option, says Donaldson) it combines with another virus subtype and a new strain emerges.

If (2) or (3) occurs, then the pandemic would become more serious.

Another topic that came up was vaccines. Sir Liam said the government hoped to get the first doses of H1N1 vaccine in August.

By the end of the year, we were told, there might be 60 million doses, enough for about half the population, based on the assumption that each person would need two jabs.

Sir Liam said there was a "cookery book element" to vaccine production, which I took to mean that the yield and dosing strategy varied from year to year. As a result, we can't yet be sure when we will get all the vaccine. Another issue, not discussed, is that the UK is just one of many countries which has contracts for vaccine, and there will be pressure from all governments to get their doses first.

Another issue that the government must grapple with is who to vaccinate first.

Sir Liam said that they had to strike a balance between protecting people at higher risk and targeting the vacine to slow the spread of the virus. The latter could be done by vaccinating everyone in outbreak areas. But Sir Liam indicated it was more likely that at-risk groups would be protected first. Nothing was said about front-line health workers, but I would expect this group to be among the first to be immunised. Andy Burnham said that, as with all such issues, they would be "led by the science".

Mr Burnham pointed out that the vaccine contracts would eventually supply 130 million doses. But officials can't yet say when all the jabs will arrive. It's quite possible that millions of Britons will encounter the virus before they are offered a vaccine - it all depends on what happens this autumn.

But Sir Liam pointed out that the vaccine will be useful even after this autumn: "In all previous pandemics, excess mortality has occured for three years after the virus appeared".

Finally, how do you know what will happen if you, your child or a friend feels ill with suspected swine flu?

The answer is: it depends entirely on where you live.

In parts of London, the west Midlands and east Berkshire (all swine flu "hot spots"), there is a shift away from containment towards "outbreak management" because there are so many cases in the community. I will set out the three phases involved in managing the outbreak in the UK:

• Containment phase: this is still be used in many areas where there are few cases. Contacts of infected people are traced and offered antivirals, schools may be closed and all those suspected of infection are tested via nasal and throat swabs, to produce a laboratory diagnosis. In this phase, it is the Health Protection Agency that takes the lead.

• Outbreak management phase: this is the policy in hotspots. Only a small proportion of suspected cases will be swabbed (so that the HPA can keep tabs on the spread of the disease) and instead, GPs will do clinical diagnosis. Schools are unlikely to close. Contacts are not traced and Tamiflu might be restricted only to those with suspected infection. Areas will change to this policy once the virus is spreading widely in their community. Each area might adapt the policy to suit their local circumstances - "flexibility" is the buzzword.

• Treatment phase: this will be a UK-wide policy, according to Sir Liam. He suggested it would be triggered when there were "west Midlands-style outbreaks in five parts of the country". The NHS takes the lead instead of the HPA and it's treated a bit like a large outbreak of seasonal flu. But the aim would be to take pressure off GPs and to encourage people to use a telephone line to report symptoms. Those who are thought to have the virus will get a unique number which will allow a "flu friend" to collect antivirals from a collection point - which may not be a traditional pharmacy. The HPA willl keep tabs on the virus and check if it is changing or developing resistance to antivirals.

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