HPV vaccine: What does it protect against and for whom is it an option?

The HPV vaccine works in various ways:

• It offers protection against the types of HPV that are most likely to cause cervical cancer. Vaccinated women are less likely to have high-grade tissue changes on their cervix that are considered to be precancerous. This greatly lowers the risk of cervical cancer.
• The risk of HPV infections on other parts of the body, such as on the vagina, penis or in the mouth, is also lowered. Tissue changes that could develop into cancer can also arise there.
• The vaccine also protects against genital warts. Although these warts are often unpleasant, they aren’t dangerous.

HPV vaccines don't have any effect on pre-existing HPV infections or genital warts.

The following vaccines are available in Germany:

• Cervarix: This vaccine provides protection against HPV types 16 and 18, which are responsible for about 60 to 70% of all cases of cervical cancer. It doesn't offer any protection against genital warts.
• Gardasil 9: Gardasil 9 provides protection against a total of 9 HPV types which are responsible for about 75 to 90% of all cases of cervical cancer. This vaccine also protects against genital warts.

The more girls and boys who have the HPV vaccine, the less of a chance the virus has to spread. So people who are not vaccinated will also be less likely to get an infection. This is what is meant by herd immunity.

The German Standing Committee on Vaccination (STIKO) at the Robert Koch Institute recommends the HPV vaccine for girls and boys between the ages of 9 and 14 years. German public health insurers cover the costs of the vaccine – and some will also pay the costs beyond this age limitation. If you miss a vaccine, you should try to get it before you turn 18, if possible. But even after that it may be a good idea. In order to provide protection before their first sexual contact, it is recommended that these young people have the vaccine sooner rather than later.

Teenagers who have already had sex could become infected with certain strains of HPV. This makes the vaccine less effective, but it can still provide protection against infection with other viruses.

Research has shown that HPV vaccines are very good at preventing HPV infections that are the most common causes of cervical cancer. They reduce the likelihood of cervical cells changing and becoming abnormal (dysplasias), and also lower the risk of cervical cancer.

If the protection lasts a long time, the following could be expected:

• Without an HPV vaccine: About 30 out of 1,000 women would develop cervical cancer at some point in their lives – if they don't go for cervical screening.
• With an HPV vaccine: About 10 out of 1,000 women would develop cervical cancer at some point in their lives – if they don't go for cervical screening.

Vaccinated women can also avoid surgery and the associate risks. This is because women with high-grade dysplasia (abnormal cervical tissue with cells that have changed a lot) have such a high risk of cervical cancer that they are typically advised to have the abnormal tissue removed.

One of the vaccines, Gardasil 9, also greatly reduces the risk of genital warts.

The HPV vaccine effectively prevents some HPV infections around the anus, on the penis and in the mouth and throat area. Genital tumors and warts that are caused by HPV are less common. Scientific studies have shown this.

The HPV vaccine aims to prevent penile and anal cancers in boys, and Gardasil is intended to prevent genital warts. These are often caused by the same strains of HPV that can cause genital warts and cervical cancer in girls and women.

Vaccinated boys are also prevented from transmitting HPV as well.

The vaccine is injected into the muscles of the upper arm. It doesn't contain viruses that are able to reproduce inside the body. Instead, it contains proteins that are like the outer coat of HPV viruses. It is not possible for the vaccine to cause an infection, but it does trigger a response from the body's immune system. Protective antibodies are made.

HPV vaccines usually involve two injections that are given five months apart. If the second injection is given before the five months are up, a third injection has to be given a few months later. Three injections are also needed if the first injection was given after the age of 14 years.

Studies with girls and women did not show any serious side effects. They may lead to various temporary skin reactions where the shot was given, including pain (in 90 out of 100 vaccinations), skin redness (in 30 out of 100 vaccinations), and swelling (in 40 out of 100 vaccinations). Problems such as indigestion, headaches, tiredness or muscle pain may also occur, but are less common.

Some girls may faint after having an injection. Because of this, it is important to stay at the doctor's for about 15 minutes afterwards.

The injection can't be given if you have a fever or an infection. If the first vaccination causes an allergic reaction, a second dose shouldn't be given.

International authorities have been monitoring reports of suspected side effects since the approval of the HPV vaccines. Because millions of girls and boys are now being vaccinated worldwide, it is to be expected simply on the basis of chance that more serious conditions will arise after vaccination. Agencies like the World Health Organization (WHO) and the European Medicines Agency (EMA) do not see any signs that any of these medical conditions arising after vaccination are actually caused by the vaccine.

It is currently not clear whether the vaccine offers long-term protection or whether it will have to be given again (booster shot) at some point. The studies with girls and women have run for 15 years at the most. The vaccine continued to offer protection during that time. This suggests that the vaccine is effective in the long term too. But because cervical cancer usually develops over several years or several decades, more time is needed to be sure.

It is difficult to say how effectively the vaccine can prevent penile and anal cancer over the long run. The studies that have been done so far were too short. It is also the case that penile and anal cancer are very rare.

It is possible to still be vaccinated after you are 18 years old. The protection that the vaccine offers is not as strong, but it is still there. Then it is possible that there have only been individual infections with human papillomaviruses or none at all. In Germany, some public health insurers cover the costs of the vaccine for people over the age of 18 years. It is a good idea to find out about that in advance.

An HPV test can be used to find out whether you currently have an HPV infection. Experts advise against getting the test done before you have the vaccine, though. The vaccine is always recommended – regardless of the results of the test. Plus, the tests would detect many harmless infections in girls and boys as well, which would be needlessly worrying. The HPV test is a good idea when used as part of cancer screening, and it is then recommended for women aged 35 and over.