HPV vaccine does prevent cervical cancer - evidence from large study confirmed

According to generalised data, girls vaccinated before the age of 16 are on average 80% less likely to get cervical cancer than those not vaccinated. The vaccine has been confirmed to cause only mild and short-term side effects, such as pain or redness at the injection site.

What HPV is and how dangerous it is

The human papillomavirus is a large group of common viruses. Some types are harmless and cause, for example, common skin warts. But "high-risk" types of HPV can lead to the development of:

• cervical cancer,

• cancers of the anus, penis, vulva, vagina,

• certain tumours of the head and neck,

• and anogenital warts.

Cervical cancer is the fourth most common malignant tumour in women worldwide. It claims more than 300,000 lives annually, with the majority of deaths occurring in low- and middle-income countries. A new analysis confirms: a large proportion of these cases could be avoided by vaccination.

Evidence from clinical trials: efficacy and safety

Thefirst Cochrane review included 60 randomised clinical trials involving 157,414 people. Researchers evaluated different vaccines - Cervarix, Gardasil, Gardasil 9 and others.

The results showed:

• all vaccines effectively prevented HPV infections associated with cancer risk and anogenital warts;

• vaccinated women were less likely to have precancerous changes of the cervix and other tissues (CIN2+, CIN3+);

• the number of women requiring treatment for HPV-related diseases decreased;

• no serious safety concerns were identified.

The most commonly reported short-term local reactions were pain, swelling or redness at the injection site. Severe side effects were very rare and occurred at about the same frequency in the vaccine and control groups.

The scientists emphasise that because HPV-related cancers take years to develop, clinical trials have not yet had time to fully capture the impact of vaccination on all cancers. However, it is already clear that vaccination significantly reduces the risk of precancerous changes, that is, it "cuts off" the chain of disease development in the early stages.

'Real life': reducing cancer and precancer in the population

Thesecond Cochrane review analysed 225 studies involving more than 132 million people in different countries. This time it was 'real-life' data - observational studies and comparisons of rates before and after the introduction of a vaccination programme.

Conclusions:

• hPV vaccination is clearly associated with reduced incidence of cervical cancer;

• the incidence of precancerous lesions (CIN2+ and CIN3+) decreases dramatically;

• the incidence of anogenital warts is reduced;

• the effect was most pronounced in those who received the vaccine at 16 years of age or younger.

Special attention was paid to safety. The researchers compared the reported "serious side effects" with large observational data and found no association between vaccination and an increase in serious complications. Much of what is being discussed on social media is not supported by practical evidence.

Why it is important to vaccinate both girls and boys

The combined results of two reviews show that HPV vaccination is one of the most effective and safest public health interventions, with the potential to prevent hundreds of thousands of cancers.

International recommendations emphasise:

• it is optimal to vaccinate both girls and boys,

• the best time is before the age of 16 and before sexual activity, when the risk of being infected with HPV is already minimal.

This protects not only future women from cervical cancer, but also men from HPV-related tumours and reduces the circulation of the virus in the population.

At the same time, the authors remind us: most of the studies so far have been conducted in rich countries. In poor countries, where cervical cancer is more common and screening is less developed, expanding the vaccination programme could have an even greater effect.

Achieving the WHO goal of eliminating cervical cancer as a public health problemrequires both:

• high HPV vaccination coverage,

• regular screening (HPV tests and cytology),

• timely treatment of precancer.

Further follow-up of vaccinated generations will allow a more accurate assessment of the impact of vaccination on other HPV-related tumours, which usually develop at older ages. But there is already enough data to say that HPV vaccination saves lives.