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Vaccine: Questions and answers

Fergus Walsh | 09:43 UK time, Tuesday, 17 November 2009

I've already written a lot about the H1N1 swine flu vaccine on this blog. But with one in six Britons currently eligible for the jab, you'll forgive me for returning to the topic again and again.

Many people have questions about the vaccine and wonder whether they should have it. On that there is very clear advice from all medical bodies and public health experts: if you are in an at-risk group (such as those with asthma, heart disease, lung problems, immune disorders or are pregnant), you really should have the vaccine.

Thomas BreuerBut what of the manufacturers of Britain's preferred swine flu vaccine? I thought it would be a good idea to put some questions to GSK, which researched, developed and produces Pandemrix.

Dr Thomas Breuer is based at GSK's massive vaccine plant at Rixensart in Belgium. His full title is Senior Vice President Global Clinical R&D and Chief Medical Officer - which means he is the person to quiz about the vaccine.

So here are ten questions about the swine flu vaccine.

1) Can you give me an update on the clinical trials involving Pandemrix?

"Pandemrix has been licensed for use by European regulators following a thorough review of manufacturing quality, the immunity it induces and its safety profile. This was based on information from clinical trials of GSK's H5N1 (bird flu) pandemic vaccine, which has been studied over several years and in more than 12,000 patients.
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"In addition, more than 3,000 people have now been vaccinated with Pandemrix as part of the ongoing clinical trials programme."

Preliminary data from the initial H1N1 clinical trials are already .

2) What about mass immunisation campaigns?

"So far, 22 countries have announced vaccination programmes; of these, more than half are using the GSK vaccine, Pandemrix. Supply commenced during October and more then 40 million doses will be supplied to governments within this first month."

3) Pandemrix contains and adjuvant, AS03. What is it and what does it do?

"An adjuvant is added to the vaccine and increases the immune response to vaccination ("adjuvant" comes from the Latin word "adjuvans", meaning "to help"). At GSK, we've been developing adjuvant technology for almost 20 years.
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"AS03 is an oil-in-water, emulsion-based adjuvant, which contains vitamin E, polysorbate (a widely used component of medicinal products) and squalene, an oil.
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"Squalene is part of a human's natural metabolism. We need it to synthesize cholesterol and some hormones. It is ubiquitous - it is found in animals and in a variety of foods, cosmetics, over-the-counter drugs and health supplements.
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"AS03 has been used in a number of candidate vaccines and tested in more than 41,000 people in various influenza vaccine clinical trials."

4) Why did you decide to create an adjuvanted pandemic flu vaccine when there is much more experience of unadjuvanted flu shots?

"The antigen is the component of the vaccine that elicits the immune response. One of the major benefits of adjuvants is that they allow less antigen to be used per dose of vaccine (for the same or even better immune response) and therefore increase the number of doses available.
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"When flu viruses drift, vaccines can often become less effective. An adjuvanted vaccine can produce a good immune response to viruses that are similar, but not exactly the same as the vaccine target.
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"GSK has demonstrated cross-protection in clinical trials for the adjuvanted H5N1 vaccine and expect to show this feature again in our ongoing H1N1 Pandemrix trials once a drift of the flu strain is observed."

5) What are the common side-effects from Pandemrix and have your trials or the mass immunisation campaigns noted any serious adverse events?

"Several thousand people have now received Pandemrix in our clinical trials, while 10 million people have now been vaccinated as part of ongoing government-led vaccination campaigns.
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"All vaccines can cause side-effects in some people. Data available from the clinical trials has shown that both Pandemrix and our adjuvanted H5N1 vaccine are generally well tolerated with a safety profile that you would expect from such a vaccine. In other words, these side effects were in line with, or slightly more frequent than has been seen with GSK's current unadjuvanted seasonal influenza vaccines.
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"The most frequently reported reactions for Pandemrix are injection site reactions (including pain, swelling, local numbness and bruising) and symptoms that are common effects of many vaccines, such as dizziness, headache, fatigue, muscle aches, malaise, mild fever, swollen or enlarged lymph nodes, nausea and vomiting.
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"More serious adverse reactions that are very rarely seen can occur. However, public health agencies as well as GSK always have to investigate whether such events are causally associated with vaccination or occur just by chance in timely association with vaccination. Vaccinating millions of people in a very short timeframe will generate many situations where events will be reported in coincidental timely association.
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"As the antigen of Pandemrix is produced in eggs, it is contraindicated for people with a history of anaphylactic reactions to eggs. To date, anaphylactioid reactions with Pandemrix have been reported very rarely and these cases were managed in the appropriate way by the healthcare practitioners involved. In addition, the number of cases reported is not in excess of what would be expected. So far no confirmed cases of Guillain-Barre syndrome have been reported."

Monitoring adverse events:

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6) What testing has been done which relates to the safety of Pandemrix during pregnancy?

"GSK has performed preclinical tests. These tests do not indicate reproductive toxicity. Pandemrix has not been formally studied in pregnant women as part of a clinical trial program.
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"We know that thousands of pregnant women have already been vaccinated with Pandemrix as part of the government-led immunisation programmes. GSK is actively working with governments to follow these women long term."

7) There is very clear evidence that pregnant women are at increased risk from H1N1 swine flu compared with the general population. Despite that, a lot of pregnant women are agonising over the decision of whether to be immunised. While your vaccine is being offered to pregnant women here, the Swiss authorities have decided that they will use an unadjuvanted vaccine for pregnant women. What's your view?

"The Swiss, just like each and every regulatory agency, have to look at the data and make their decision. We have data from animal studies and from other research. From a theoretical point of view, we have studied our adjuvants carefully and don't believe there is a risk - but we don't have clinical data specifically in pregnant women.
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"But we are not promoting the vaccine for any particular group. We give the data and leave it up to regulators. France has decided to give unadjuvanted vaccines to pregnant women. In Canada, the government has decided to use our vaccine for pregnant women, as has the UK.
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"Each mother and each doctor has to weigh up the known risks of getting H1N1 and the theoretical risk of having the vaccine and make a personal decision. It's worth pointing out that pregnant women have been immunised with seasonal flu vaccines for years."

8) Where is the vaccine made and how many doses of Pandemrix are coming off the production line each week?

"GSK has two manufacturing sites, based in Dresden in Germany and Quebec in Canada. We will be supplying a total of more than 440 million doses to more than 40 governments with H1N1 vaccine produced by these two sites.
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"The development, manufacture and shipping process is complex and a tightly-controlled process. In addition to vaccine production, it's also important to make sure all vaccine doses meet the stringent quality control standards and regulatory requirements before being shipped.
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"As a result of the complex process involved, production varies from week to week. As of the end of October, GSK has shipped more than 40 million doses and in the weeks ahead we'll be supplying tens of millions of doses of vaccine to countries all over the world.
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"To date, 6.4 million doses have been sent to the UK. GSK continues to make every effort to supply the maximum supply possible from its manufacturing sites."

9) Will you be making doses available privately and what will the likely cost be?

"No. We are committed making Pandemrix available to governments to support efforts to protect their people. Some governments may decide to use the private sector to distribute their doses.
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"We have also allocated 20% of production at our Quebec site to supporting developing countries. This includes a donation of 50 million doses to the World Health Organization. At GSK, there is no preferential treatment for staff."

10) Can you understand that some people feel instinctively suspicious of big pharma and its motives? GSK posted quarterly profits of £1.44bn last month. How would you and GSK respond to the charge that profits are more the driving force rather than patients, and that the pandemic is perhaps seen as a good source of income for the company?

"Companies like GSK have to take significant financial risks upfront to be ready to provide a solution and invest a significant part of their profits in development of future vaccines. We have already spent £2bn in developing technologies to respond to an influenza pandemic and increasing capacity at our vaccine and antiviral manufacturing sites.
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"We are trying to strike a balance between the expectations of society and our shareholders, who justifiably want to see a return on the risks we take. The only entities currently providing solutions to fight the pandemic are publicly-traded companies. And on a personal note, making a difference in public health is what makes me tick and what gets me out of bed into work every day."

Update 1510: Some readers have asked for more detail in Question 8; I have altered the post above to quote Dr Breuer's answer in full.

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