Why the vaccine against cervical cancer is not such a simple shot


  • A National Technical Advisory Group on Immunisation (NTAGI) has proposed that a vaccine against the human papillomavirus (HPV), which causes cervical cancer, be introduced in India’s Universal Immunisation Programme (UIP).
  • NTAGIs are, according to the World Health Organisation (WHO), a “technical resource providing guidance to national policymakers and programme managers to enable them to make evidence-based immunisation-related policy and programme decisions”.

Crvical Cancer:

  • Globally, cervical cancer is the fourth most frequent cancer in women; among Indian women, it is the second most frequent, according to the WHO.
  • A 2012 study published in the Indian Journal of Medical and Pediatric Oncology said, quoting WHO figures, that India accounted for a third of all global cervical cancer deaths, with 1.32 lakh new cases diagnosed annually, mostly in advanced stages.
  • While India has seen a fall in the incidence of cervical cancer over the last three decades, the number of cases remains high in rural areas, and where sanitation and hygiene are low. These were among the reasons for the NTAGI to propose the HPV vaccination programme for girls.

The Virus

  • HPV is a group of viruses known to cause penile cancer in men, and cervical, vaginal, anal and vulvar cancer in women. HPV can also lead to throat or rectum cancer in both men and women. The virus is transmitted through intimate contact, for instance, via sexual intercourse, oral or anal sex. The HPV sub-types 16 and 18 — which cause over 70% of cervical cancer cases — produce two proteins which turn off tumour-suppressing genes and lead to abnormal growth in the cervical lining. While infection may not always lead to cervical cancer, the virus poses a higher risk for HIV-infected persons, smokers, those with high dependency on hormonal contraceptives and with early initiation into sexual activity.

The Vaccine

  • The HPV vaccine is given thrice within six months to girls aged 9-13 years, before they become sexually active. In India, two vaccines — Merck’s Gardasil and GlaxoSmithKline’s Cervarix — are available. Cervarix provides immunity against HPV sub-types 16 and 18; Gardasil protects against sub-types 16 and 18 — as well as against 6 and 11, which cause 90% of genital warts in men and women. Post-vaccination, a girl should ideally undergo pap smear tests every three years to check for pre-cancerous or cancerous cells.

The Concerns

  • In India, the primary concern is cost, given the huge population and stretched healthcare budgets.
  • A single shot of Gardasil costs approximately Rs 3,000 and Cervarix, about Rs 2,000. Each girl requires three shots. “At present, no data suggests that either Gardasil or Cervarix can prevent invasive cervical cancer as the testing period is too short to evaluate the long-term benefits of HPV vaccination.
  • The longest available follow-up data from phase II trials for Gardasil and Cervarix are 5 and 8.4 years respectively,” a 2013 study by specialists at the Tata Memorial Hospital (TMH), Mumbai, said. The study added that India is already witnessing a declining trend in cervical cancer due to better hygiene, changing reproductive patterns, improved nutrition and water supply. (Sudeep Gupta et al, ‘Is Human Papillomavirus Vaccination Likely to be a Useful Strategy in India?’: South Asian Journal of Cancer: 2013 Oct-Dec; 2(4): 193-197).
  • “It’s better that we strengthen the reasons behind this trend rather than expose the entire population to the vaccine. It has not been proven to prevent a single cervical cancer death,” Professor Rajesh Dikshit, co-author of the study, told The Indian Express. Dr Rajendra Badwe, Director, TMH, said cervical cancer is declining in urban areas due to better hygiene, and it may further shrink if this extends to rural areas.
  • In his letter to Modi, Swadeshi Jagran Manch national co-convener Ashwani Mahajan, too, drew attention to the high cost of the vaccine. At three shots of Gardasil at MRP for 6.2 crore Indian girls aged 9-13 years, the cost to the government will be over Rs 56,000 crore.
  • Further, there are over 100 HPV sub-types against which the vaccine does not provide immunity. Dr Sudeep Gupta, Professor of Medical Oncology, TMH, said the vaccine can even cause rare side-effects such as regional pain syndrome. In Japan, the HPV vaccine recommendation was temporarily suspended after reports of this neurological problem.

The Counter-View

  • A WHO position paper published in May 2017 noted that the “WHO Global Advisory Committee for Vaccine Safety (GACVS), which regularly reviews the evidence on the safety of HPV vaccines” had concluded in January 2016 that the “available evidence did not suggest any safety concern”.
  • The paper recorded that “by 31 March 2017, globally 71 countries (37%) had introduced HPV vaccine in their national immunisation programme for girls, and 11 countries (6%) also for boys”. The vaccine, the WHO said, should be “administered if possible before the onset of sexual activity, i.e., before first exposure to HPV infection”.
  • Global healthcare professionals have rejected as baseless online campaigns against the vaccine, which have resulted in temporary dips in take-up rates in some countries like Japan, Ireland and Denmark.

Source:Indian Express

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