HPV vaccines effective in reducing infections, precancerous warts: WHO

Widespread vaccination programmes can help achieve WHO's global call to eliminate cervical cancer as a public health problem  

By DTE Staff
Published: Thursday 27 June 2019
Photo: Getty Images

Getting vaccination for Human papillomavirus (HPV) can effectively decrease infections, anogenital wart and precancerous lesions, according to a World Health Organization (WHO)-funded study.

HPV is a viral infection that spreads through skin-to-skin contact and has more than 100 varieties.  

HPV 16 and 18, responsible for 70 per cent of cervical cancers, could be significantly reduced after vaccination, showed the study published in the journal The Lancet on June 26, 2019.

Cervical cancer is the fourth-most common cancer among women, with an estimated 570,000 new cases diagnosed worldwide in 2018. 

In the study, the team analysed data from 65 studies, with sample size of 60 million people from 14 high-income countries — including 23 for HPV infection, 29 for anogenital warts and 13 for CIN2+ lesions for over eight years. 

They found:  

  • HPV infections reduced by 83 per cent in girls (aged 13-19) and 66 per cent in women (aged 20-24 years)
  • anogenital wart diagnoses declined by 67 per cent in girls (aged 15-19) and 54 per cent in women (aged 20-24) and 31 per cent in women (aged 25-29); 48 per cent in boys (aged 15-19) and 32 per cent in men (aged 20-24 years)
  • precancerous cervical lesions (CIN2+) decreased by 51 per cent in girls (aged 15-19 years) and a 31 per cent in women (aged 20-24 years)

The study demonstrated how widespread vaccination programmes can help achieve WHO's global call, last year, to eliminate cervical cancer.

"Because of our finding, we believe the WHO call for action to eliminate cervical cancer may be possible in many countries if sufficient vaccination coverage can be achieved,” said Marc Brisson, a professor at the Laval University in Canada. 

Moreover, in 2016, the global health body had also recommended HPV vaccination of multiple age cohorts of girls (9–14 years old) when the vaccine is introduced in a country, rather than vaccination of a single cohort.

As a result, countries with both multi-cohort vaccination and high vaccination coverage showed a decline in anogenital wart diagnoses by 88 per cent among girls and 86 per cent in boys (aged 15-19 years), the study showed.

On the other hand, countries with single-cohort or low routine vaccination coverage showed a dismal performance — reduction of 44 per cent among girls and 1 per cent among boys.

In the case of CIN2+, there was no decrease in countries with single-cohort vaccination or low routine coverage, while countries with multi-cohort vaccination and high vaccination coverage had a 57 per cent decline.

Importantly, the efforts needs to be scaled-up in low and middle-income countries (LMICs), where the burden of disease is far greater than in high-income countries, the researchers stressed.

Of the 570,000 new cases diagnosed in 2018, around 85 per cent occurred in less developed nations. 

According to Silvia de Sanjose, of PATH — a US-based health organisation — the LMICs are facing challenges such as high vaccine cost and competing budget priorities, inadequate vaccine supply and lack of awareness of vaccine impact and vaccine hesitancy.

“It will be crucial to continue monitoring the population-level impact of HPV vaccination to examine the full effect of changes in strategies and quantify the effect of vaccination in low-income and middle-income countries,” Brisson added.

“The study emphasises the importance of redoubling our efforts to tackle the fiscal, supply, and programmatic barriers that currently limit HPV vaccine programmes; with these efforts, HPV vaccination could become a hallmark investment of cancer prevention in the 21st century,” Sanjose added, in a linked article.

A study, published in The Lancet Oncology journal earlier in February 2019, showed that scaling-up HPV vaccine and cervical screening can help eliminate cervical cancer in 149 out of 181 countries by 2100 and up to 13 million cases of cervical cancer by 2050.

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