H1N1 vaccine: The best option

Last April, the world was introduced to a new virus, known as the pandemic (H1N1) 2009 virus or, as it is more commonly known, the swine flu. The pandemic seems to be waning now but the possibility exists that it could return later this year since transmission of the virus remains an issue. In the past, some influenza pandemics returned the following year, in some cases with greater severity.

The Malta Association of Public Health Medicine, which represents public health specialists in Malta, feels the need to stress the fact that vaccination continues to be the effective option for prevention of this potentially-serious condition.

It is essential to keep in mind that infection with the H1N1 influenza virus can lead to serious, even fatal, illness in anyone. One particular group are pregnant women, who are among the groups at highest risk. According to the Centre for Disease Control, of the first 700 pregnant women reported to have influenza since April, one in seven was admitted to intensive care and 28 died from complications. In an average flu season, 25 of every 10,000 women in the third trimester of pregnancy are hospitalised with flu-related complications. Hence, it is essential that pregnant women get the jab and get protected.

Newborns are also extremely vulnerable. Past flu studies have found that, when women get flu shots before giving birth, they help build immunity for their child that is particularly helpful during the infants' first few months of life. Since vaccination cannot be given before six months of age, it is important for parents and carers to be protected. Vaccination is also recommended for breastfeeding women and anyone who has close contact with infants.

Members of the public continue to express concern about reports of potential problems with the "new" vaccine. Although mild side effects are reported in about half of people who take the vaccine, including soreness at site of injection, fever, malaise and headache, there were no reports of widespread serious adverse events. One must remember that this vaccine was prepared according to the same standards and protocols as previous seasonal influenza vaccines. In fact, the vaccine technology used in the production of influenza inoculation has been around, with a few modifications, for 60 years. One needs to emphasise the fact that vaccine use is a predictable and effective way to prevent disease.

Yet, still, just drop by a grocery store or listen to street talk about this vaccine... there is lots of talk about "scares" of this vaccine, which is putting people off from taking it. One of these is the worry about the use of adjuvants in the vaccine. Actually, adjuvants are agents that augment and increase the response to a vaccine without having any specific effect themselves. The adjuvant used in the H1N1 vaccine is made with vitamin E, water and squalene. Squalene is an organic substance found in all humans; our bodies use it to synthesise sterols, such as cholesterol and steroids. It is also found in all animals, plants and a variety of foods, cosmetics and medicines.

Some websites have linked squalene to the anthrax vaccines leading to Gulf War Syndrome but those allegations have been shown to be false. Squalene was never used in those vaccines. And while anti-squalene antibodies were found in some of those with Gulf War Syndrome, they are also found in the blood of people who have never received a vaccine containing squalene. Over 22 million doses of squalene-containing vaccines have been administered around the world. "The absence of significant vaccine-related adverse events following this number of doses suggests that squalene in vaccines has no significant risk," says the World Health Organisation.

Another scare is the use of mercury in the vaccine. The flu vaccine contains a small amount of thiomersal as a preservative. Most seasonal and swine flu vaccines have this chemical. It is necessary for the stability of the vaccine as it is delivered in multi-dose vials.

Thiomersal is a mercury-based preservative but it is made of ethylmercury. It does not contain methylmercury, which can accumulate in the body and has been linked to neurological damage. Studies have shown that ethylmercury from vaccines disappears rapidly from the blood.

Also, the levels of ethylmercury in vaccines are minute and have not been shown to cause harm.

It is estimated that there is four times as much mercury in a can of tuna fish as there is in the thiomersal in the H1N1 flu vaccine.

One query about vaccination is when a person is not certain whether s/he have already suffered from H1N1 infection. Only those who underwent laboratory testing can know with certainty that they had swine flu.

Most people will not know if they have had H1N1 and, hence, it is recommended that the vaccine is still taken unless one has had a positive lab test for H1N1. Even if a person has been infected with H1N1 it is considered safe to be vaccinated.

Looking at the whole picture, the H1N1 vaccines available can protect those who have not yet been affected by the highly-infectious, and very occasionally severe or lethal, virus.

The Malta Association of Public Health Medicine strongly recommends that everyone takes the H1N1 vaccine. The vaccine is safe and prevents pandemic influenza, which has killed over 15,000 persons worldwide and caused illness in millions.

Dr Gauci is president, Malta Association of Public Health Medicine