Health Talk | Why HPV vaccines are an effective shield against cervical cancer

HPV, transmitted through intimate contact, often remains undetected, yet it can lead to various cancers. Understanding its risks and prevention is crucial

HPV, or human papillomavirus, is a common virus that can cause cancers. It is spread through intimate skin-to-skin contact. One can get HPV by having vaginal, anal, or oral intercourse with someone who has the virus, even if they don’t exhibit signs or symptoms.

Certain types of HPV lead to cervical cancer and India, in particular, has a population of 511.4 million women who are at risk of developing this cancer

The Union health ministry is likely to incorporate HPV testing into the National Cancer Control Programme, to screen women for cervical cancer, this newspaper reported last week. Certain types of HPV lead to cervical cancer and India, in particular, has a population of 511.4 million women who are at risk of developing this cancer, according to the International Agency for Research on Cancer (IARC)'s 2023 Factsheet.

Current estimates indicate that every year 1,23,907 women are diagnosed with cervical cancer and 77,348 die from the disease. Cervical cancer ranks as the second most frequent cancer among women in India between 15 and 44 years of age. Nearly 5% of women in the general population are estimated to harbour cervical HPV-16/18 infection at a given time, and 83.2% of invasive cervical cancers are attributed to HPVs 16 or 18.

HPV infection and cancer

 

According to the US Centre for Disease Control, most HPV infections (9 out of 10) go away by themselves within two years. But sometimes, HPV infections will last longer and can cause cancers of the cervix, vagina, and vulva; penis; anus; back of the throat (called oropharyngeal cancer), including the base of the tongue and tonsils.

Prevention and HPV vaccine

 

HPV vaccination is meant to prevent cancer-causing infections and precancers. Persons up to the age of 26 years should get the HPV vaccine if they were not fully vaccinated already and it is not recommended for anyone older than 26, as current clinical trial results suggest that the efficacy of the vaccine drops considerably after 25 years. HPV vaccination of adults provides less benefit because more people in this age range have been exposed to HPV already.

Vaccine dosage

 

Children from ages 11–12 years should get two doses of HPV vaccine, given 6 to 12 months apart. HPV vaccines can be given starting at age 9.

Dose number 1: 11–12 years (can start at age 9); Dose number 2: 6–12 months after the first dose

Children who start the HPV vaccine series on or after their 15th birthday need three doses, given over 6 months.

Last year, the Serum Institute of India launched Cervavac, an India-made HPV vaccine priced at ₹2,200 for persons from nine through 26 years of age. In further impetus to the prevention of cervical cancer in India, Union finance minister Nirmala Sitharaman announced that the government will encourage HPV vaccination for girls in the age group of nine to 14 years while presenting the interim budget in February.

Vaccine efficacy

 

In the US, HPV infections and cervical precancers have dropped since 2006, when HPV vaccines were first used in the United States. Among teen girls, infections with HPV types that cause most HPV cancers and genital warts have dropped 88%. Among young adult women, infections have dropped 81%. Among vaccinated women, the percentage of cervical precancers has dropped by 40%. The protection provided by HPV vaccines lasts a long time. People who received HPV vaccines were followed for at least about 12 years, and their protection against HPV has remained high with no evidence of decreasing over time.

Side effects

 

Over 15 years of data have shown that HPV vaccines are very safe and effective. Like all vaccines, scientists continue to monitor the HPV vaccines. Common side effects are mild and get better within a day or two and include pain, redness, or swelling in the arm where the shot was given; fever; dizziness or fainting (fainting after any vaccine, including the HPV vaccine, is more common among adolescents than others); nausea; headache or feeling tired; muscle or joint pain. As per available evidence, the vaccine does not cause fertility problems.

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