Swine flu vaccine uptake

Several newspapers have reported that pregnant women and other vulnerable people are refusing to have the swine flu vaccine. The Times reported that a poll of GPs found that only 46% of people who were offered the vaccine have accepted it, and one doctor estimated that only 5% of pregnant women have had it.

The news reports are based on a “snapshot” survey of 107 GPs. The survey asked how likely they were to hit the government’s target of vaccinating at least half of their patients who are under 65 and in high-risk groups this winter. GPs were also asked to estimate how many of the people who were offered the vaccine in their practice had agreed to have it (the uptake).

It is not clear if the experiences of this relatively small sample of GPs is representative of the 30,000 GPs in the UK. This picture of overall uptake is based purely on these 107 GPs’ estimates. It is possible that these GPs chose to take part in the survey themselves, and that GPs who chose not to take part may have a different experience of vaccine uptake.

Based on this survey, it can’t be assumed that there is similar vaccine uptake nationwide, or that particular groups, such as pregnant women, are more likely to reject the vaccine.

What are the news reports based on?

These news reports are based on two articles in Pulse , a magazine for GPs. Both articles are on the swine flu vaccination programme, which has been in progress since late October. One article, on overall uptake of the vaccine, was based on a “snapshot” survey of GPs that was recently carried out by the magazine. The other article, on uptake in pregnant women, may be from the same survey, but this was not made clear.

One of the articles reports that GPs are “braced” to miss a target that was set by the government to vaccinate at least half of all people in high-risk groups aged under 65 against swine flu during this winter’s campaign. The other article reports that pregnant women are rejecting the vaccine because of fears over its safety.

Pulse surveyed 107 GPs, asking them whether they felt they would achieve this target in their practice and to estimate how many of the people who were offered the vaccine in their practice had accepted so far. The GPs could also make any other relevant comments.

What did the survey find?

The survey found that only 37% of GPs believed that their practice could achieve the government’s target, based on their experience so far. Just over half (53%) said they would not hit the target, and 10% said it was too early for them to say. The reasons given by GPs for not hitting the target are a low uptake of the vaccine by those who were offered it and delays in receiving vaccine supplies. Just over half the practices had started the vaccination campaign, and these practices estimated that less than half the people offered the vaccine had accepted it.

In the article on vaccine uptake in pregnant women, one GP estimated that only 5% of pregnant women in their practice had agreed to be vaccinated, while another GP estimated that the figure in their practice was less than 25%. Other GPs stated that there was scepticism about the vaccine among their pregnant patients.

Do these findings represent all GPs? 

This survey cannot answer that question. It was a relatively small survey which asked GPs’ opinions on the likelihood of reaching vaccination targets and their estimates of vaccine uptake in their practices. It is not clear how these GPs were selected to take part in the survey, how many of those who were asked agreed to take part, or which areas of the country were covered. The figures on overall uptake were based on the GPs’ estimates.

The only figures that estimated uptake in pregnant women came from two GPs, but one estimate was five times higher than the other (one in 20, and less than one in four). It is difficult to gauge uptake based on this limited survey, and it is not possible to say whether these results are representative of the entire country.

Regarding reasons for low uptake, the GPs could only state the concerns that their patients had reported to them. It is not possible to say how representative these reports were of people’s reasons for not having the vaccine. It is also not clear whether certain at-risk groups are more likely to reject the vaccine than others.

What are the problems with supply?

Pulse reported that each practice in England and Wales, regardless of size, was due to receive an initial delivery of 500 doses of the vaccine, and GPs should be able to order further deliveries from mid-November. However, the magazine says that larger practices reported not having enough doses of the vaccine to go round, which has led some of them to delay their vaccination campaigns.

What reasons were given for rejecting the vaccine?

The GPs surveyed said that people who rejected the vaccine did so because of concerns about its safety and the risk of side effects, which were reported as headaches, sleeplessness and stomach cramps. Some GPs also reported that patients were concerned over an ingredient in the vaccine called thiomersal.

Pandemrix is one of the two swine flu vaccines being used in the UK. It contains a very small amount of thiomersal as a preservative. It is added to prevent bacterial or fungal contamination occurring during the preparation, storage and use of the vaccine.

In the 1990s, some people raised concerns about the use of thiomersal in vaccines, which lead the WHO Global Advisory Committee on Vaccine Safety to review the scientific evidence about its safety, which it did most recently in 2006. It concluded that "there is no evidence of toxicity in infants, children or adults exposed to thiomersal in vaccines."

Are the vaccines safe?

Both swine flu vaccines (Pandemrix and Celvapan) have been authorised for use by the European Medicines Agency (EMEA). Vaccines would not be licensed if they were considered unsafe.

What is known about the safety of these vaccines is based on clinical trials of prototype bird flu vaccines and trials using the swine flu vaccine itself. Based on these studies, the swine flu vaccine has been judged to be acceptably safe for use.

People who are offered the vaccine and are concerned about its safety should discuss this with their doctor.

Does the vaccine have any side effects?

The Medicines and Healthcare products Regulatory Agency (MHRA) reports that “as with any vaccine, the swine flu vaccines will cause side effects in some people, although not everybody will have a side effect. The most common side effects will be injection site reactions (pain, swelling and/or redness), headaches, dizziness, muscle aches, mild fever and fatigue. These side effects are mainly mild and last only two to three days. Some of these symptoms may be similar to a mild flu-like illness, although it should be stressed that the vaccines cannot cause swine flu itself.”

Because clinical trials are relatively small, they may not identify very rare side effects. To identify these, the side effects of the swine flu vaccine will be monitored as it is used. It is important to note that the same is done for all new medicines and vaccines, not just the swine flu vaccine.

Who should be vaccinated and why?

Although swine flu is mild in most people, some people who get swine flu have serious complications, which can be fatal. To reduce the risk of these complications, the vaccination programme prioritises people who are most at risk of having complications from swine flu. These priority groups are:

• People aged between six months and 65 years who belong to at-risk groups that would usually be offered the seasonal flu vaccine (see below).
• Frontline health and social care workers.
• Pregnant women.
• People who live with those whose immune systems are compromised, such as cancer patients or people with HIV/AIDS.
• People aged 65 and over who would usually be offered the seasonal flu vaccine.

Frontline health and social care workers are prioritised because they deal with at-risk groups, so are more likely to catch and spread swine flu to at-risk patients. Prioritising them also aims to ensure that the health service will continue to run smoothly during the pandemic.

People who would usually receive the seasonal flu vaccination include those who have:

• Chronic respiratory disease, such as chronic obstructive pulmonary disease (COPD).
• Chronic heart disease, such as heart failure.
• Chronic kidney disease.
• Chronic liver disease, such as chronic hepatitis.
• Chronic neurological disease, such as Parkinson's disease.
• Diabetes requiring insulin or oral diabetic medications.
• Immunosuppression (a suppressed immune system) due to disease or treatment.

Why is it important for pregnant women to be vaccinated?

Pregnant women are one of the groups that are more likely to have serious complications if they get swine flu, which could result in miscarriage and premature labour.

There is evidence that pregnant women are at increased risk of severe disease and of being admitted to hospital with flu-related problems. The risk increases as the pregnancy progresses, and women in the third trimester of pregnancy are particularly at risk (WHO 2009; Jain et al , 2009; Jamieson et al , 2009).

The World Health Organization has stated that 7–10% of all hospitalised patients with swine flu are pregnant women in their second or third trimester. Pregnant women are 10 times more likely to need care in an intensive care unit than the general population (WHO, 2009).

Complications in pregnant women, based on information on seasonal flu, may include pneumonia and cardiorespiratory complications (Kort BA et al , 1986; Neuzil KM et al , 1998).

Both swine flu vaccines have been licensed for use in pregnant women, but it is recommended that pregnant women are given Pandemrix. This is because it appears to give adequate levels of antibodies after a single dose, protecting the recipient more quickly than Celvapan, which requires two doses given three weeks apart.