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Cuauhtemoc Ruiz-Matus and Lucia Helena de Oliveira | HPV vaccines work

Published:Thursday | July 19, 2018 | 12:00 AMCuauhtemoc Ruiz-Matus and Lucia Helena de Oliveira

The scientific evidence is compelling: Vaccines work! Their power to prevent disease has been widely proven - so much so that disability and death from diseases such as smallpox and polio are now a thing of the past. Thanks to the availability of the vaccine against humanpapilloma virus (HPV), the same could also be true for cervical cancer.

Since the vaccine against HPV became available in 2006, countries have been using it to protect girls against infection from HPV strains 16 and 18, which are directly responsible for seven out of 10 cases of cervical cancer. Each year in the Americas, 83,000 women are diagnosed with this disease and 35,000 die from it.

Many countries that have introduced the vaccine have already seen a significant impact, particularly when it comes to preventing infection. A systematic review of the vaccine's impact revealed that high vaccination coverage leads to a 90 per cent reduction in HPV 16 and HPV 18 infections, and a 45 per cent reduction in cases of precancerous lesions in women that have been vaccinated.

Ensuring HPV vaccination coverage of more than 90 per cent in the Americas, along with the provision of cervical cancer screening and treatment programmes, could prevent thousands of cases of HPV each year and eliminate those cases of cervical cancer prevented by the vaccine.

This translates to thousands of women who will not become cancer patients, will not suffer the effects of chemotherapy, and will not risk losing their lives to this preventable disease.

It is estimated that by the end of 2016, more than 33 million girls had been vaccinated against HPV in the Americas. This alone will prevent more than 307,000 cases of HPV and 133,000 deaths from cervical cancer in the future.

The vaccine also has a variety of other benefits beyond the reduction of HPV and related cervical cancer in women and girls. Studies have also found a decrease in HPV infection in unvaccinated men, given that women who don't become infected with HPV also do not transmit the disease to their partners. Additionally, evidence shows that vaccinating against HPV helps prevent other cancers, including of the vulva, vagina, penis, anus, and throat.

According to recommendations from the Pan American Health Organization/World Health Organization (PAHO/WHO), girls between the ages of nine and 14 should be vaccinated with two doses of HPV vaccine administered between six and 15 months apart. HPV vaccines given to this age group are more effective, and girls have a better immune response.

Since 2006, thirty-two countries and territories in the Americas have incorporated HPV vaccination into their routine vaccination schedules. Currently, more than 80 per cent of girls in the region have access to the vaccine.

Since the HPV vaccine has been licensed, more than 270 million doses have been applied all over the world. It is extremely safe and effective, and any doubts about its safety are unfounded, lack scientific validity, and serve only to cause rejections and delays in vaccination. The best thing parents can do is to vaccinate their daughters on time and with the recommended doses.

WHO's Global Advisory Committee on Vaccine Safety (GACVS) constantly analyses all available data and studies on reactions associated with the vaccine in order to ensure its safety. The side effects (headache, redness and pain at the injection site, fever, nausea, and dizziness) do not differ from those caused by any other vaccine, and it is vital to remember that the benefits of vaccination outweigh any risk.

In developing countries, many women find out too late that they have HPV, generally when seeking treatment for genital warts, pre-cancerous lesions, or more series issues, which reduces their chance of survival. This is why a cervical cancer prevention programme that includes universal HPV vaccination for girls, as well as screening services and treatment for those who need it, has the potential to end cervical cancer.

Vaccinating girls today is the only way to ensure that they have a happy and prosperous tomorrow, with one less serious cancer to worry about.

- Cuauhtemoc Ruiz-Matus is chief of immunisation at PAHO. Lucia Helena de Oliveira is PAHO's regional adviser in new vaccines. Email feedback to columns@gleanerjm.com.