Swine flu vaccine: your questions answered
Updated on 21 October 2009
As the national swine flu vaccination programme begins, we submitted a selection of viewers' questions to our panel of experts from the Science Media Centre. Here are their answers.
Professor Robert Dingwall, Director of Institute for Science and Society, University of Nottingham and Dr Mike Skinner, Department of Virology, Imperial College London answer your concerns. Find out how to get the vaccination here.
The answers provided are of a general nature. If you have a specific concern, you are advised to contact your doctor or the official government swine flu helpline on 0800 1 513 513.
Q: You say the vaccine is only mainly availabe for pregnant women and people that are considerably ill.
So why on the news are there men and doctors and nurses been given the jab when they are the same as everybody else. Why should they get priority?
RD: Front-line health and social care workers (i.e. people who are directly in contact with patients) are being offered priority vaccination for two reasons -
1. So that they do not spread infection around the people that they are looking after, because people are infectious with H1N1 flu before the symptoms appear. As Florence Nightingale wrote, the first duty of a hospital is to do the sick no harm - admitting people and having them catch flu from the staff would fail that test!
2. So that the NHS has as many people as possible at work, if and when the the infection rate increases and more people need hospital treatment, particularly in intensive care. It would be tragic for beds to be closed just because there were too few staff available for work when sick people needed them.
People need to have the vaccine now because it takes two to three weeks to build up maximum protection.
MS: They are much more likely to be exposed, they could spread it to patients (including those who are at particularly high risk due to predisposing conditions), and we do not want them off sick at the very time when the health service might be most stretched due to a winter wave of influenza.
Q: I am currently seven months pregnant. I am fit and healthy with a low-risk pregnancy so far and no underlying medical conditions.
I am currently trying to decide whether to have the vaccine. Finding reliable information about the risks posed to me and my baby, both for having the vaccine and not having the vaccine, is making the decision extremely difficult.
Articles in the press tend to focus on scare stories, whilst "advice" from the government is just for all pregnant women to have it. Also, it seems to be a clean-sweep policy for pregnant women to be immunised without taking into consideration whether the advice changes for women at different stages of pregnancy.
MS: The most dangerous times for exposure to swine flu in pregnancy seem to be the second and third trimesters (months four to nine).
Q: Neither source, as far as I can see from my research, has given a balanced account of the pros and cons of having the vaccine or not for pregnant women. It's not the actual strain within the vaccine that worries me, it's the chemicals and other elements it's mixed with.
MS: Your GP will try to rule out sensitivities you may have to the components (e.g. severe egg allergy) but I assume you refer primarily to thiomersal, a mercurial compound used as a preservative to prevent contamination of the multi-dose vials.
Mercury is in our environment and we ingest it all the time in very small doses (for instance in fish). It only becomes a problem when it accumulates to sufficient levels. The toxicology is pretty well understood and the levels of mercury in the thiomersal are way below dangerous levels (someone weighing 50 kg would reach their advisable daily dose limit recommended by WHO.
Pregnant women and children would be closer to their limits but only for that one day - the limits are designed to protect us from continuous low-level exposure on each and every day. The vast majority of adults received thiomersal in their own childhood vaccines. There's careful consideration at: http://www.immunisation.nhs.uk/files/thiomersalfsht.pdf
Q: We are being offered Pandemrix which contains this ingredient the WHO says should not be given to pregnant women, but the government spokespeople just gloss over this without addressing the WHO concerns, which does not fill me with confidence.
My doctor has informed me that the other vaccine, the Baxters option, that does not contain this ingredient has not yet been granted its licence.
I just find it quite amusing that the government is fanatical in their advice to pregnant women not to eat rare meat or blue cheese, but seem quite happy to advise that we're all injected with all sorts of chemicals in this vaccine.
Ed Sykes (Science Media Centre): The Baxters vaccine has been licensed - http://www.emea.europa.eu/ for information on both the Baxters (Celvapan) and GSK (Pandemrix) products and the evidence they had to provide to get the licenses.
Q: What are thought to be the risks associated with giving flu vaccine to pregnant women? There's concern - not sure about what.
MS: Nor am I. The recommended exposure limits to mercury compounds are set lower for pregnant women, but remember those limits are set to protect you and your offspring from continuous low-level exposure each and every day.
Q: How can they be sure it's safe for pregnant women? What will happen with pregnant women in last few weeks of pregnancy? Will protection be offered in post-natal period?
RD: Anthony Fauci, who is the director of the US National Institute for Allergy and Infectious Diseases, was recently interviewed in the US press and remarked on the problem of getting people to understand that, just because this was a new strain of flu, it was not being treated with a new vaccine.
What we have is basically a seasonal flu vaccine with a new component. The seasonal flu vaccine is adjusted every year to match the strains expected to be in circulation that winter.
What has happened this year is that extra efforts have been made to offer both the, revised, seasonal vaccine and the H1N1 vaccine.
The H1N1 vaccine uses the same, well-proven technologies and has been approved by the same regulators. Vaccines using adjuvants to increase their effectiveness are relatively a newer technology. The, rather slow-moving processes of WHO have not fully caught up with clinical experience, which has not identified any adverse effects for any group on which it has been used.
What any pregnant woman has to weigh up is the proven risk of serious illness and, rarely, death from the disease and the benefits to herself and her baby, who will inherit some protection from the antibodies stimulated by the vaccination, against theoretical and speculative risks, which have no foundation in the experience of millions of previous seasonal flu vaccinations.
The reason why pregnant women are particularly at risk is that pregnancy itself compromises the immune system - otherwise your body would think your baby was foreign tissue, like a transplanted organ, and reject it.
Once you have had the baby, your immune system returns quite rapidly to its normal state and there would be no special benefit from vaccination. Risks do seem to increase late in pregnancy, but the vaccine takes two to three weeks to have its full effects so there are advantages in taking it up sooner rather than later.
MS: The immunity will not only protect you after the birth but your baby will benefit from maternal immunity (transferred in the womb and by breast-feeding) during a time when it is under considerable threat from the influenza.
Q: Will asthma sufferers who get the free annual flu jab get the swine flu jab at the same time as normal jab?
MS: They can be done at the same time. Whether your GP will do so might depend on his supply of stocks of each.
Q: Do asthmatics qualify for the vaccine?
MS: I expect your GP will be inviting you.
Q: Will the vaccine be given in schools?
MS: Not in the initial stages, not until there's more available.
Q: I'm lucky in that I'm not very susceptible to colds and flu and am concerned that having the vaccination could be detrimental to my health. Are my concerns ill founded and would I have to option not to be vaccinated?
RD: The answer depends on how old you are. People like me who had flu before 1957 seem to have some residual cross-immunity. However, if you are a teenager or a young adult, then you do need to recognize the small but real risk of very serious illness and, rarely, death.
20 per cent of UK deaths have occurred in young healthy adults with no other risk factors. Obviously, this means that the other 80 per cent occur in people with other underlying health conditions, including pregnancy, and that is why they are getting priority.
If the vaccine is offered to everyone, once the most vulnerable have been vaccinated, then you will be absolutely free to choose whether to have it or not. The UK government has made it clear that there will be no compulsion on anyone.
MS: There is no obligation. As I biologist I'd want good evidence that I was "not very susceptible" before turning down this vaccine.
Q: Just had seasonal flu vaccine. Is it OK to have swine flu vaccine as well? I am over 65.
RD: There is no reason why you should not have both at the same time - just not in the same arm. However, you will not be offered H1N1 vaccination at this time unless you have some other condition that puts you at risk - the priority groups are different for swine flu and seasonal flu vaccination.
MS: Yes, but you may not be invited by your GP unless you have predisposing conditions that put you at particular risk from swine flu.
Q: I am 43 years old and can go into AF whilst under stress or during illness. Vomiting can induce this. Do I fall into the at risk catergory?
RD: You would need to check this with your GP.
Q: My children (aged eight and five) appeared to have had swine flu when it was at its height at the end of July (they had all the symptoms listed on the government website, and were offered tamiflu).
Although quite unwell for several days, they recovered OK. Of course they were not swabbed to confirm that it was swine flu.
If the vaccine is offered to someone who has already had unconfirmed swine flu, will it cause problems (i.e. a reaction) for the individual?
MS: No.
Q: Do you advise that they be vaccinated anyway?
MS: Yes.
Q: What's the efficacy of the vaccination against swine flu in otherwise healthy people?
MS: Given the age range of those being vaccinated, and the fact that the swine flu doesn't seem to have changed its coat much at all since it emerged, you'd expect it to be at least 80 per cent (of course, you can't test this by challenging people with swine flu - you can only check their serological/antibody response and monitor protection epidemiologically).
Q: If you've had swine flu, must you still have the vaccine? I'm an acute asthmatic.
MS: There is no MUST to it anyway. If you were lab-tested positive for H1N1 you should be protected already, though it will do no harm to be vaccinated too. If the diagnosis was only presumptive then you would be strongly advised to accept the invitation.
Q: Is the swine flu vaccine a disabled form? Can you catch swine flu from the vaccine?
RD: Because a lot of people will not have a diagnosis of H1N1 flu that has been confirmed by laboratory tests, they will be included in the offer of vaccination if they fall into a priority group. The vaccination will not do them any harm and will confer some benefit, if, in fact, they had some other illness in the first place.
The vaccine does not contain any live virus and there is no possibility of catching flu from it. At most, you will experience some soreness at the injection site and, in a few cases, a brief and minor feverish episode, which shows that your immune system is responding correctly to the vaccine.
MS: It's completely dead and contains only part of the virus coat. No you cannot catch swine flu from the vaccine.
