Q&A: H1N1 vaccines

Al Jazeera’s Dan Nolan examines the facts – and fiction – surrounding the H1N1 vaccines.

Swine flu H1N1 laboratory test

The World Health Organisation says getting vaccinated is the best protection against any pandemic flu as the northern winter approaches.

But with more than a dozen H1N1 vaccines in production, each with different ingredients, finding the best and safest can be hard work.

Al Jazeera’s Dan Nolan goes beyond the fear and hysteria to explain what you need to look for to make an informed decision.

Do I need the H1N1 vaccine?

While the overall fatality rate of H1N1 is not much different to the seasonal flu, some people are affected much worse if they catch this one. Unlike seasonal influenza which mainly kills the elderly, the current pandemic influenza strain has affected younger people.

Vaccination is strongly recommended for pregnant women and those with underlying chronic conditions, including:

– heart disease;
– asthma and other lung diseases;
– cancer;
– diabetes;
– kidney disease;
– neurological disease;
– other chronic conditions (talk to your family doctor)

It is also recommended that the vaccine be administered to parents and guardians of infants up to six months old, children between the ages of six months and four years of age, those who are severely obese, and frontline health workers.

Is the H1N1 vaccine safe?

If you have had a bad reaction (i.e. more than a sore arm or a headache) to a vaccine before then the H1N1 vaccine may not be right for you. But generally the H1N1 vaccine will be very similar to seasonal flu shots which have a long history of providing good protection with very few nasty side effects.

In an effort to quickly get large amounts of the H1N1 vaccine out to the world, some pharmaceutical companies have added extra ingredients that may not normally be used in their flu vaccines.

According to the World Health Organisation (WHO), these ingredients are safe. But you should find out exactly what is in the H1N1 vaccine being made available to you and discuss with your doctor whether it’s right for you.

Below is a summarised table of  the pharmaceutical companies which are manufacturing vaccines, the contents of these medications, and which countries have ordered batches:

Drug companies Orders Clients Stage Ingredients
Glaxo SmithKline 440 million USA, UK, Canada, Oman Approved by European regulator, distribution underway • Contains thiomersal and adjuvant
Sanofi-Aventis 120 million USA, France, Brazil Distribution started in USA, other countries to receive supplies in November • Contains thiomersal (in multi-dose vials only)
• US-licensed vaccine has no adjuvant
• European vaccine will contain adjuvant
AstraZeneca/ Medimmune 40 million USA Available in USA; nasal spray, not injection • No thiomersal, no adjuvant
• Licensed only for ages 2-49 who are not pregnant or have respiratory illness
• Contains live H1N1 strain (most others contain dead)
CSL 60 million USA, Australia, Singapore Available in Australia • Contains thiomersal (in multi-dose vials only)
• No adjuvant
• Not licensed for children under 10
Sinovac 6 million China Available in China • No thiomersal, no adjuvant
Novartis ? USA, Germany, Oman Approved by European regulator, distribution underway • Contains thiomersal (in multi-dose vials only)
• US-licensed vaccine has no adjuvant
• European vaccine will contain adjuvant
Baxter 80 million UK, France, Ireland, New Zealand Approved by European regulator, distribution underway • No thiomersal, no adjuvant
Safe for people with egg allergies (most others are not)
• Not yet approved for pregnant women/people with respiratory illness

What is an adjuvant and why is it used in H1N1 vaccines?

Adjuvants, derived from a Latin word meaning ‘to help’, are compounds used to enhance a vaccine’s ability to elicit a more aggressive response from your body’s immune system.

Using an adjuvant means less than of the antigen (the dead H1N1 virus) is required as it tricks the immune system into sending out more antibodies thus providing improved protection. Adjuvants may also help provide immunity if the virus mutates.

They have been criticised by some as a money-saving method for the pharmaceutical companies who can effectively make more vaccine with less antigen. The WHO says data from the millions of adjuvanted seasonal flu vaccines administered in Europe has shown that they are safe to use.

Not all H1N1 vaccines contain adjuvants so if it remains a concern for you, it can be avoided.

Australia began offering free vaccine shots throughout the country last month [GETTY]

What is squalene and why is it used in H1N1 vaccines?

Squalene is a naturally occurring substance found in plants, animals, and humans. It is used by some pharmaceutical companies as an adjuvant (see above). Several scientific studies have found that squalene has caused immune disorders in animals. It has also been linked to illnesses suffered by US soldiers who served in the first Gulf War.

The WHO says squalene was not administered to US soldiers and therefore cannot be the cause of their health problems. It also says that over 22 million doses of squalene-containing flu vaccine has been safely administered across Europe and it has “no significant risk”.

Not all H1N1 vaccines contain squalene so if it’s a concern for you, it can be avoided.

What is thiomersal and why is it used in H1N1 vaccines?

Thiomersal is a mercury-based preservative that has been used in medical products and vaccines for more than 60 years.

It is required in multi-dose vials to prevent contamination during repeated use.

Single-dose vaccines do not require thiomersal but many governments have requested multi-dose vials to be able to vaccinate more people faster.

Therefore some pharmaceutical companies are adding thiomersal to their H1N1 vaccines despite it not being an ingredient of their seasonal flu shot. Thiomersal was removed from all US vaccines as a “precautionary measure” even though there is no evidence it is harmful.

It has not been used in childhood inoculations in Britain since 2004 but will be included in most H1N1 vaccines coming to the UK and Europe.

Despite media speculation to the contrary, there is no scientific evidence anywhere in the world that thiomersal in vaccines has caused any developmental or neurological abnormalities, such as autism, Attention Deficit Hyperactivity Disorder (ADHD) or any other health problem.

Thiomersal-free vaccines will be available in the USA.

What is Guillain-Barré syndrome?

Guillain-Barré syndrome (GBS) is a rare and sometimes severe condition affecting the body’s nerves. What causes GBS is not clear, but it generally happens after infections such as stomach bugs, coughs and colds.

It is thought to be due to the immune system mistakenly attacking the body’s own nerves. This results in muscle weakness and sometimes paralysis, which can last for weeks to months. Most people recover completely but the consequences can be severe in some.

Can I get Guillain-Barré syndrome from the H1N1 vaccine?

The chances of GBS affecting you after any flu vaccine (not just H1N1) are extremely low – about one in a million. But studies also show that GBS is four to seven times more likely after an attack of the actual flu than after the influenza vaccine.

In the USA in 1976 a vaccine used against a different strain of swine influenza was associated with around 400-500 people developing GBS – or about one case per 100,000 people vaccinated.

Such a high occurrence of GBS after flu shots has not been witnessed since.

The above is a summary of information available on the websites of the World Health Organisation and the Centre for Disease Control and Prevention. It should not be treated as a substitute for medical advice.

Al Jazeera is not responsible or liable for any action by a user based on the information provided above.

Al Jazeera is not liable for the contents of any external internet sites listed, nor does it endorse any commercial product or service mentioned or advised on any of the sites.

If concerned about the H1N1 virus and what vaccines may be available in your area consult your family doctor or general practitioner and visit:

http://www.cdc.gov/h1n1flu/ http://www.who.int/csr/disease/swineflu/en/index.html.

Source: Al Jazeera