Cervical cancer Does the HPV vaccine really provide safe protection?

Vaccination significantly reduces risk of cervical cancer

The vaccine against human papillomavirus (HPV) offers young women good protection against the precursors of cervical cancer. This has now been shown by a large-scale meta-analysis of the Cochrane organization. According to the study, women who were vaccinated at the age of 15 to 26 would have a significantly lower risk of developing high-grade cervical intraepithelial neoplasia. The analysis also showed that there are no indications of severe side effects from the vaccine.

Researchers find no evidence of serious side effects

Cervical cancer is a malignant tumor that develops from altered cervical tissue. The major risk factor for this form of cancer is infection with the human papillomavirus (HPV). Since 2006, there is a vaccine against HP viruses, which recommends the Standing Vaccination Commission (STIKO) as a standard vaccine for all girls from nine to 14 years. Comprehensive data analysis has now shown that the vaccine has been shown to protect young women from precursors of cervical cancer while being safe for serious side effects, according to the Cochrane organization report.

A study by the Cochrane organization has shown that vaccination against HPV viruses massively reduces the risk of dangerous tissue changes to the cervix. (Image: Kzenon / fotolia.com)

High risk types 16 and 18 are the most dangerous

According to the Deutsches Krebsforschungszentrum, more than 170 different HPV types are currently known. About 40 of them mainly affect the genital area and the anus (genital HPV types) and are mainly sexually transmitted. Some of the virus types result in benign genital warts (e.g., HPV 6 and HPV 11), but others cause tissue alterations that can lead to cancer. HPV 16 and HPV 18, which are responsible for about 70% of all cases of cervical cancer, are among these so-called high-risk types.

Researchers evaluate data from more than 73,000 women

The Cochrane researchers evaluated the results of 26 randomized trials in a total of 73,428 women over the last eight years worldwide for the meta-analysis. Most of the women in the studies were under the age of 26, and three of them were also studied between 25 and 45 years of age.

The bivalent vaccine against HPV 16 and 18 and the quadrivalent vaccine against HPV 16/18 and two low-risk HPV types causing genital warts were evaluated. The newer vaccine, targeting nine HPV types, was not included in the review, informs the Cochrane organization.

It was found that girls and young women who are vaccinated against these two high-risk viruses between the ages of 15 and 26 are well protected from the precursors of cervical cancer, the doctors report. Thus, two out of every 10,000 women who did not have HPV infection at the beginning of studies in the trials later had precancerous stages of cancer despite vaccination. In the control group, however, 164 subjects were affected.

In older women, vaccination offers less protection

The physicians were also able to show that the vaccine offered protection even if the young women had previously been exposed to pathogens. Regardless of whether or not infected with HPV, the experts found tissue changes in only 157 out of every 10,000 women that could develop into cancer. In unvaccinated volunteers in the control group, however, these changes were seen in 341 women. If the vaccination was carried out at a later age, the experts did not provide good protection anymore. This may be because older women were more likely to be exposed to HPV viruses.

Further long-term studies necessary

However, researchers at the Cochrane organization point out that the studies studied did not last long enough to examine the development of cervical cancer. Because it can take many years to decades for a cervical carcinoma to develop from a tissue change. "Cervical cancer can develop many years after HPV infection and after lesion formation," says Oncologist Jo Morrison of Musgrove Park Hospital in Somerset, UK. Accordingly, long-term follow-up studies are needed to detect the effects of HPV vaccination on cervical cancer rates, the expert said.

"The vaccine aims to get the immune system to produce antibodies that can block a subsequent natural HPV infection. These data show that immunization against HPV infection protects against cervical precancer, and it is very likely that this will reduce cervical cancer rates in the future. However, it can not prevent all forms of cervical cancer and it is still important to screen regularly, even if you have been vaccinated, "Morrison emphasizes.

More than 1,500 deaths a year

Cervical carcinoma is the fourth most common malignant tumor in women worldwide. According to the Association of German Tumor Centers e.V., 528,000 first diagnoses are diagnosed annually and about 266,000 deaths are registered as a result of the disease. According to the RKI, more than 4,600 women in Germany contracted cervical cancer in 2014, and about 1,540 women are currently dying from it each year. 30 years ago, it was more than twice as many, according to the RKI. (No)