A trial looking at a vaccine to prevent HPV infection, the cause of cervical cancer, in women aged 26 years and over (HPV 015)

Cancer type:

Cervical cancer

Status:

Results

Phase:

Phase 3

This trial was done to find out if a vaccine can prevent HPV infection in women aged 26 years and over.

The human papilloma viruses (HPVs) are a group of viruses. There are many different types of HPV, some of which can infect the cervix. The different types of virus have numbers to tell them apart.

More about this trial

Some types of HPV are called ‘high risk’ because they cause cervical cancer. Nearly all women with cervical cancer are found to have high risk HPV. Even so, it is likely that many women have HPV at some point, but do not go on to develop cervical cancer. Your immune system usually fights the infection and it goes away by itself.

In some women, the infection lasts for a long time. When this happens, it may cause the cells of the cervix to change and become abnormal. If left untreated, some of the abnormal cells may go on to become cancerous.

This trial looked at a vaccine called Cervarix to try and prevent HPV 16 and HPV 18, two of the high risk types of HPV. Doctors hoped that the vaccine would lower the number of women with HPV, and that it may in turn also lower the number of women who develop abnormal cells and cervical cancer.

Summary of results

The research team found that fewer women who had the vaccine had HPV, and that it didn’t cause too many side effects.

This trial recruited nearly 5,000 women over 26 years old, from several countries around the world. They were put into 1 of 2 treatment groups at random. Neither they nor their doctor could decide which group they were in.

Half had 3 vaccine injections over 6 months
Half had 3 dummy (placebo) injections over 6 months

Around 6 months after treatment, the research team looked at how many women had HPV 16 or HPV 18. They analysed the samples in a number of different ways and found that,

for HPV 16 it was

5 out of 1,545 women (0.3%) who’d had the vaccine
27 out of 1,521 women (1.8%) who’d had the placebo

for HPV 18 it was

2 out of 1,597 women (0.1%) who’d had the vaccine
10 out of 1,571 women (0.6%) who’d had the placebo

and for combined HPV 16 and 18 it was

7 out of 1,898 women (0.4%) who’d had the vaccine
36 out of 1,854 women (1.9%) who’d had the placebo

So the rate of HPV infection was low in all groups, but overall it was about 5 times higher in the group who had dummy injections.

Some women in both groups had side effects. More women in the vaccine group had pain, redness and and swelling at the injection site. The number of women with other side effects was low, and similar in each group. They looked at the number of women in each group who had a side effect within the first month of treatment. They found that

246 out of 2881 women (9%) in the vaccine group had a side effect related to the injection
192 out of 2871 women (7%) in the placebo group had a side effect related to the injection

The research team concluded that for every 5 people in the placebo group who had HPV 6 months after treatment, just 1 person in the vaccine group had it. And that the side effects were similar in each group.

We have based this summary on information from the team who ran the trial. As far as we are aware, the information they sent us has not been reviewed independently (peer reviewed Open a glossary item ) or published in a medical journal yet. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.