I'm trying to keep it as straight and factual as possible, and hopefully leaving my own personal biases out of it – I hope I succeeded. I’m not really trying to argue for and against vaccination itself. I think the benefits of a safe vaccine are self evident so the following is intended to help us weigh up the safety of the current offerings.

I've cited sources but I have no medical qualifications and actively encourage you to correct me. Consider this a starting point to evolve into some useful answers.

Apologies for length...

How prevalent is swine flu in NI?

Chief Medical Officer Dr Michael McBride said: "At present our level of flu continues to be much higher in Northern Ireland than in the rest of the UK and is at the highest rate ever recorded in Northern Ireland.

http://news.bbc.co.uk/1/hi/northern_ireland/8309116.stm

But Health Minister Michael McGimpsey said up to 30 per cent of the population may become ill with flu at some point during the pandemic.

http://www.newsletter.co.uk/news/Swine-flu-cases-could-reach.5617825.jp

What vaccines are on offer?

Pandemrix — http://www.emea.europa.eu/influenza/vaccines/pandemrix/pandemrix_pi.html

Everyone including pregnant women is getting Pandemrix except those allergic to eggs who will get:

Celvapan — http://www.emea.europa.eu/influenza/vaccines/celvapan/celvapan_pi.html

As far as I can tell, neither has been tested on pregnant women.

The European Medicines Agency (EMEA) say almost word for word the same thing about each vaccine, except Celvapan (NOT Pandemrix) showed some side-effects in rats.

From the EMEA documents:

4.6 Pregnancy and lactation

There are currently no data available on the use of Celvapan in pregnancy. Data from pregnant women vaccinated with different inactivated non-adjuvanted seasonal vaccines do not suggest malformations or fetal or neonatal toxicity.

Animal studies with Celvapan do not indicate reproductive toxicity (see section 5.3).

The use of Celvapan may be considered during pregnancy if this is thought to be necessary, taking into account official recommendations.

Celvapan may be used in lactacting women.

...snip...

5.3 Preclinical safety data

Non-Clinical data obtained with the pandemic vaccine using an H5N1 vaccine strain demonstrated alterations in liver enzymes and calcium levels in repeat dose toxicity studies in rats. Such alterations in liver function have not been seen to date in human clinical studies. Alterations in calcium metabolism have not been examined in human clinical studies.

Animal reproductive toxicology studies do not indicate harmful effects in regard to female fertility, embryo-foetal and pre- and post-natal toxicity.

http://www.emea.europa.eu/humandocs/PDFs/EPAR/celvapan/spc/emea-spc-h982pu17en.pdf

4.6 Pregnancy and lactation

There are currently no data available on the use of Pandemrix in pregnancy. Data from pregnant women vaccinated with different inactivated non-adjuvanted seasonal vaccines do not suggest malformations or fetal or neonatal toxicity.

Animal studies with Pandemrix do not indicate reproductive toxicity (see section 5.3).

The use of Pandemrix may be considered during pregnancy if this is thought to be necessary, taking into account official recommendations.

Pandemrix may be used in lactacting women.

...snip...

5.3 Preclinical safety data

Non-clinical data obtained with the mock-up vaccine using a H5N1 vaccine strain reveal no special hazard for humans based on conventional studies of safety pharmacology, acute and repeated dose toxicity, local tolerance, female fertility, embryo-fetal and postnatal toxicity (up to the end of the lactation period).

http://www.emea.europa.eu/pdfs/human/pandemicinfluenza/Pandemrix_PI_23oct09.pdf

Properties of the Vaccines

I’ve tried to compare and contrast the two vaccines. There’s quite a lot more detailed information below this so this is really a summary. This is the current state of my knowledge but I’d very much appreciate anyone who can confirm or refute this. It would be good to get it as accurate as possible.

Pandemrix

1. Available now
2. Takes effect quickly
3. Confers immunity on baby, who cannot be vaccinated directly
4. Untested on pregnant women
5. Contains an adjuvant containing squalene (see later)
6. Provides some protection against swine flu variants (thanks to adjvant)
7. Contains Thiomersal, a mercury based compound (see later)
8. No side effects in animal

Celvapan

1. Not available now and may not ever be available
2. Takes effect less quickly
3. Confers immunity onto baby, who cannot be vaccinated directly
4. Untested on pregnant women
5. Contains no adjuvant
6. Does not provide as much protection against swine flu variants (no adjvant)
7. Contains no Thiomersal
8. Side effects seen in animals but not affecting reproduction

Thiomersal

http://en.wikipedia.org/wiki/Thiomersal

Thiomersal is a mercury containing compound.

From Channel 4 news:

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 http://www.channel4.com/news/articles/uk/swine+flu+vaccine+your+questions+answered/3395297

Things get woolly now, but I tried to do some sums to work out how much was in a vaccine shot. I was comparing against eating cod. Cod is a low-mercury fish, less than tuna for example and massively less than shark/swordfish. (http://gotmercury.org/article.php?list=type&type=75)

I concluded that about 50g of cod has the same amount of mercury as the vaccine. The weekly recommendation for pregnant women is something like 2 portions, which would be around 300g or 400g I’d guess?

My major assumption is that mercury is mercury and that it doesn't matter what compound it is in. I'm not sure this is really the case and could be the flaw in my logic.

My working is below anyway for those who want to check and verify:

Amount of mercury in the vaccine is: 5ppm (parts per million) Vaccine is: 0.5ml Assume density is twice that of water Weight of vaccine = 1 gram Weight of mercury in vaccine = 5ppm of 1 gram = 5 millionths of a gram Cod is: 0.1ppm mercury Weight of mercury in 50g cod = 0.1ppm of 50g gram = 5 millionths of a gram

Adjuvants and Squalene

Adjuvants

http://en.wikipedia.org/wiki/Immunologic_adjuvant

My understanding: if you inject vaccine with adjuvant (e.g. aluminium salts) it provokes the immune system to really pay attention for a while. Hence you get a better response to the vaccine. But the 'provocation' is local to the vaccine site, so there is a greater chance of skin reaction. Evidence seems to point to adjuvants being a good thing from an individual perspective not just a government perspective (use less, get more immunity) but the issue of skin reactions is probably more acute in cultures where beauty is very important. Seems to be that adjuvants are a trade-off between a slightly increased local skin reaction vs. vastly stronger immunity per unit of vaccine.

One big plus side: it seems that it also results in a good effect in terms of cross-reactions i.e. helping your body to fight off new/different but related strains. Basically, you can get better protection from the adjuvanted vaccine.

Also:

Butler-Jones said some pregnant women may prefer an adjuvanted formulation, because it's likely to protect more broadly against mutated strains of the virus if and when they arise, and because it can be taken in smaller doses.

http://www.healthzone.ca/health/newsfeatures/swineflu/article/691201--canada-to-offer-different-swine-flu-vaccine-for-pregnant-women

From BBC:

It is a slightly different story for the GSK vaccine - and that is the one that most pregnant women will end up being offered in the UK.

Unlike Baxter's vaccine, it contains an adjuvant - a chemical to boost the immune system response. There is not as much evidence on adjuvanted vaccine use in pregnant women - although there is nothing to suggest it is unsafe.

Indeed, Professor David Salisbury, the government's director of immunisations and one of the World Health Organization's key advisers on vaccines, has sought to reassure women that the GSK jab is a better option.
He has pointed out that as it is effective with one dose, it offers better protection than the Baxter version which requires two doses several weeks apart and, therefore, longer without protection against the virus.

http://news.bbc.co.uk/1/hi/health/8200504.stm

Squalene

http://en.wikipedia.org/wiki/Squalene

There seems to be unfounded controversy around squalene. There was a study that said Gulf War 1 veterans suffered GW syndrome as the result of squalene in their vaccines. It was later discovered they received no squalene at all but this discredited report is often quoted.

From the WHO website:

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.

Why do some people think squalene in vaccines carries a risk?

A few people have tried to link the health problems of Gulf War veterans to the possible presence of squalene in the vaccines these soldiers received.

One published report suggested that some veterans who received anthrax vaccines developed anti-squalene antibodies and these antibodies caused disabilities.

It is now known that squalene was not added to the vaccines administered to these veterans, and technical deficiencies in the report suggesting an association have been published.

http://www.who.int/vaccine_safety/topics/adjuvants/squalene/questions_and_answers/en/