Friday, October 16, 2009

Vaccination gets the green light

Fergus Walsh | 17:42 UK time, Friday, 16 October 2009

The long-awaited UK-wide programme of vaccination against H1N1 swine flu will begin next week.
The first to get immunised will be the most vulnerable people in the population - namely, high-risk patients in hospital (for example, those with leukaemia who have a weakened immune system).
The Chief Medical Officer for England, Sir Liam Donaldson, who is the government's main advisor on tackling the virus, gave further details (for England) at his weekly press briefing.

The GSK vaccine Pandemrix has become the jab of choice for the NHS, despite the government also buying stocks of a second vaccine Celvapan, from another manufacturer, Baxter. This is partly due to production problems with the Baxter vaccine.

Sir Liam Donaldson urged at risk groups, including pregnant women, to get immunised:
"I don't want to see anyone dying of an illness that can be prevented by vaccination. Only this week we have seen two deaths among pregnant women: one in Scotland and another in Wales."
The head of immunisation at the Department of Health, Professor David Salisbury, said those over 10 years of age would need just one dose of Pandemrix vaccine, because clinical trials had shown that it was sufficient to offer good immunity.

Those under 10 will need two jabs, spaced three weeks apart, because their immune systems don't respond as well.

By contrast, anyone who has Celvapan will require two doses. Professor Salisbury said he specifically wanted pregnant women to have the Pandemrix GSK jab, because it meant they would be protected quicker. He said:
"If a pregnant woman has an interval of three weeks to wait for immunity to kick in, that could put the pregnancy at risk, so it is seriously beneficial for them to be protected after one dose of Pandemrix."
Professor Salisbury pointed out that both vaccines had been licensed and were safe. The Baxter vaccine, which is not made using eggs, would be used for those who have a rare egg allergy. The key difference between the two vaccines is that Pandemrix has an adjuvant, or booster chemical, which is designed to boost the body's immune response.
Adjuvanted flu vaccines have been around for at least a decade, but there is not nearly the same degree of clinical data as with unadjuvanted flu jabs.

Because of the lack of clinical data, the WHO suggested in July [267KB PDF] that swine flu vaccines without adjuvants, should be used in pregnant women, where possible.
This suggestion came from the influential Strategic Advisory Group of Experts on Immunization (Sage). That would have meant Celvapan being used, not Pandemrix.

But Professor Salisbury, who chairs Sage as well as being the head of immunisation at the Health Department, indicated that this advice was now out of date.
"It was made before the GSK vaccine was licensed and based on what we knew at the time. The regulators were able to look at studies involving pregnancy in animals and at other clinical data."
SAGE meets in two weeks and is expected to revise its earlier guidance. So what should pregnant women do?
The clear advice is that those who are pregnant should be immunised because they are at considerably higher risk, as a result of the body's natural suppression of the immune system.
The further along the pregnancy, the greater the risk to the mother and her unborn child. Earlier this week, a pregnant teenager in Scotland died after contracting swine flu, leading to the death of her unborn child. Recently, a new mother in Wales died two weeks after giving birth following infection with the virus.

Many will want to find out as much information as possible about Pandemrix before agreeing to be immunised. There have been clinical trials - including data published today.
To date, 2,000 people have received the jab. None of those was pregnant because ethical committees will not usually allow pregnant women to take part in trials.
So what is in the adjuvant, known as AS03, found in the GSK jab? The key ingredient is something called squalene, which is derived from fish oil. The World Health Organization has an explanatory note on this.

Squalene (wikipedia) has been used in flu vaccines before, as the WHO makes clear:
"22 million doses of Chiron's influenza vaccine (FLUAD) have been administered safely since 1997. This vaccine contains about 10mg of squalene per dose. No severe adverse events have been associated with the vaccine."

and WHO say

Are squalene-containing vaccines safe?

  • Over 22 million doses of squalene-containing flu vaccine have been administered. The absence of significant vaccine-related adverse events following this number of doses suggests that squalene in vaccines has no significant risk. This vaccine has been given primarily to older age groups.
  • As this vaccine and new squalene-containing vaccines are introduced in other age groups, post-marketing follow-up to detect any vaccine-related adverse events will need to be performed.

Saturday, October 10, 2009

"Lucky break" slows spread of swine flu - Donaldson

Chief medical officer now optimistic about the scale of the epidemic
Britain's swine flu outbreak is slowing down, possibly as the result of a "lucky break" in the way the virus has behaved, the chief medical officer said today.
Sir Liam Donaldson, who has been generally cautious in his weekly predictions on the likely course of the epidemic, was more optimistic as he suggested during a news conference that the peak number of cases may be lower than previously thought.
The rate of increase looks to be nothing like the weekly doubling of cases that experts had predicted. Last week, there were 18,000 new cases of swine flu, rising from 14,000 the previous week and 9,000 the week before that.
"We are well into the second wave of pandemic flu, having had the first wave in July, but it's proving so far to be a slow burner," Donaldson said. "It's possible that it might peak at a lower level – and an earlier level – than expected which would be incredibly positive news.
"It means we could get the vaccine programme well under way. If this virus has another peak up its sleeve, as in 1968, we might be able to avert that completely."
"We may have got a lucky break in how the virus has behaved at the start of our flu season and we may be able to get the vaccine out there before our flu season really gets under way," said Donaldson. "I'm looking at it very optimistically."

The body which advises ministers on vaccination - the Joint Committee on Vaccination and Immunisation - has been meeting today and a key point of discussion has been whether to extend H1N1 swine flu vaccination beyond at-risk groups. If this does happen, it would be healthy children who would be the first group targeted, on the grounds that children are the most likely to catch the disease, and the most likely to require hospital treatment.
Vaccination against seasonal flu has already begun in many parts of the UK and swine flu jabs will be sent to GPs from later this month. Sir Liam said:
"There's been a supply of half a million doses of Baxter vaccine in warehouses for some time. We expect to get considerable numbers of the GSK vaccine quite soon. The only doses here so far (of the GSK vaccine) have been for clinical trials and there hasn't been a major delivery yet."

Wednesday, October 7, 2009

Seasonal flu vaccine offers 'some protection'

Fergus Walsh | 00:01 UK time, Wednesday, 7 October 2009
Research from Mexico City published on suggests that the seasonal flu vaccine may offer some protection against swine flu, particularly the most severe complications of the disease.

Friday, October 2, 2009

Swine flu science: overview

Swine flu science: overview

NHS ChoicesOct 02, 2009 12:30:00 GMT

This page brings together the latest science and developments on the swine flu pandemic, offering a single accessible resource for both health professionals and the general public.
You will find a range of regularly updated links to scientific resources on the Pandemic (H1N1) 2009 virus listed below. We will also be critically appraising new research on swine flu as it is published.
For the latest, more general news on swine flu in the UK, including prevalence, NHS policy and guidance, go to swine flu latest from the NHS.
We encourage comments and suggestions from the scientific community on the development of this page.

Recent swine flu appraisals by Bazian

For a full list of related articles see our archive of swine flu news.

Useful links

Journals and research

UK government

International government

The genetics of swine flu

Health & Medical organisations

Blogs, wikis, alerts and other tools