Vaccines for swine flu by Fergus Walsh

Vaccines for swine flu

Fergus Walsh | 16:30 UK time, Friday, 25 September 2009

Plans to vaccinate millions of people in Britain against H1N1 swine flu have taken a step forward today. The European Medicines Agency (EMEA) has approved Pandremrix, manufactured by GlaxoSmithKline (GSK) [36Kb PDF].

A licence won't be granted until it's been approved by the European Commission, but that is expected in the next couple of weeks. GSK is one of two suppliers of pandemic vaccine to the UK, the other being Baxter. But its vaccine did not get approved today. The EMEA said that there had been an issue about the quality of the vaccine, but that they hoped to resolve that next week. The Baxter vaccine is not made using eggs, so it will be useful for those rare people with an anaphylactic reaction to egg.

The UK has contracts for up to 132 million doses of pandemic vaccine - enough for everyone in Britain to receive two shots. But early data suggests one jab may be sufficient. This is what the EMEA had to say on this:

"The Committee is currently recommending a two-dose vaccination schedule, at an interval of three weeks, for adults, including pregnant women, and children from six months of age. The Committee acknowledged that there are preliminary data suggesting that one dose may be sufficient in adults. The Agency is expecting further data from ongoing clinical studies over the coming months and these recommendations may be updated."

It should mean that Britain is on track to begin begin an immunisation campaign next month. Just a reminder of which groups will be vaccinated first. Here's the list, in order of priority:

• individuals aged six months and up to 65 years in the current seasonal flu vaccine clinical at-risk groups
• all pregnant women, subject to licensing considerations on trimesters
• household contacts of immunocompromised individuals
• people aged 65 and over in the current seasonal flu vaccine clinical at-risk groups

So how many people will that involve? Getting figures for the whole of the UK means contacting four separate health departments, which is why very often, you will see only the figure for England. My understanding is that the total is 11.45 million people for the UK (9m England; 1.3m Scotland; 0.75m Wales; 0.4m Northern Ireland). In addition, more than two million frontline health workers will be immunised in tandem with the above groups.

The government now has an agreement with GPs to vaccinate the at-risk groups. But this will take a huge amount of organisation, especially since the seasonal flu campaign will continue.

There are many questions which arise from the planned immunisation campaign, not least how big the uptake will be. NHS staff members have a very poor record of taking the seasonal flu jab, with only 16% uptake.

Many pregnant women may also be loath to have the jab and rather hope for the best that they don't get the virus, and that if they do, get it mildly. Pregnant women are at elevated risk of both catching swine flu and getting complications. In order to carry a child through pregnancy, the body's immune system is naturally suppressed.

The first person to die from complications of swine flu in June was a 38-year-old woman in Scotland who'd given birth prematurely. She had underlying health conditions. Andremember Sharon Pentleton? She got swine flu when six months pregnant and had to be flown to Sweden for specialist treatment. Fortunately, she is now recovered and her baby is due next month.

Both of those cases are extreme examples. The vast majority of pregnant women who catch swine flu will have a mild infection. But the expert advice is that they should be immunised. What is not clear yet is how early in the pregnancy it will be recommended and whether or whether it will be restricted to women who are in the second and third trimesters (that is, from three months onwards).

The final recommendation on timing rests with the Joint Committee on Vaccination and Immunisation (a sort of NICE for vaccines). I've been looking at the minutes of their meeting in August [63Kb PDF] and it gives an idea of what they are thinking on this:

"The committee supported the use of either vaccine once licensed in pregnant women. The committee noted that many women are advised not to take any kind of drug in their first trimester unless recommended by a medical practitioner. The committee advised that all pregnant women, including those in their first trimester, could receive the vaccine. Both swine flu vaccines are inactivated and there is no evidence that the foetus is at any risk when the mother is immunised with an inactivated vaccine such as the seasonal flu vaccine. Seasonal flu vaccines have been used for a number of years in the US with no evidence of harm. The committee noted that vaccinating pregnant women would not only provide benefit to them but also provide benefit to the infant, when born, through vertical transfer of maternal antibodies."

The JCVI also sees no reason why you can't have your pandemic flu jab at the same time as a seasonal flu vaccine. This is what they had to say on that:

"The committee advised that since the swine influenza vaccines are inactivated, they could be co-administered with all other vaccines including seasonal influenza and childhood vaccines. Vaccines should be given at separate sites, preferably in different limbs. If given in the same limb, they should be given at least 2.5 cm apart."

So what will the government do with all those extra vaccines, once the at-risk groups are immunised? My hunch is that they may decide to offer the jab to all children, not just to those who are at risk of complications. But that decision does not need to be taken now, and instead officials will wait to see how the virus behaves in the months ahead.