07 Sep Innovation in the fight against HPV-related diseases
Issued by IPASA
It’s only been 10 years since the vaccine against human papillomavirus (HPV) was launched, but already several international studies have shown that it is effective and is working – better than expected, in fact. For those girls and women who have been vaccinated, especially, that means the very real probability of a future that is free of cervical cancer.
Not only that, but a host of other HPV-related diseases are no longer a concern, which means fewer deaths due to HPV-related disease and reduced costs treating those diseases.
“A recent review study of a large number of published trials showed some amazing results,” says Dr Konji Sebati, CEO of the Innovative Pharmaceutical Association South Africa (Ipasa). “If we look at girls who were vaccinated before being exposed to HPV in those countries where there is high vaccine uptake, we’re seeing reductions of about 90% for HPV infection, about 90% for genital warts, about 45% for low-grade cellular cervical abnormalities, and about 85% for high-grade cellular cervical abnormalities.
“I don’t think we’ve fully understood the full public health potential that HPV vaccination has.”
Those numbers were reported in a study on the impact and effectiveness of the HPV vaccine, published in the Clinical Infectious Diseases journal in June this year.
HPV is the commonest sexually transmitted virus worldwide, and most people are typically infected shortly after they become sexually active. HPV-related diseases are a significant source of illness and death worldwide: cervical cancer is the fourth most frequent cancer in women and accounts for 7.5% of all female cancer deaths.
HPV infection causes virtually all cervical cancers, as well as about 90% of anal, 70% of vaginal, 50% of penile, 40% of vulvar and 13%–72% of oropharyngeal cancers, as well as 90% of ano-genital warts.
“The rollout has been very successful in developed countries worldwide, with more than 205-million doses of 4vHPV vaccine having been distributed worldwide by the end of last year,” says Sebati. “In the US, the vaccine has been around for 10 years; in South Africa we’ve not quite reached that milestone, so figures for efficacy are not yet available.
“The impact of the vaccine was first seen for HPV infections and genital warts. Both of these have short incubation periods. However, the effects on cervical lesions, which take longer to develop, are now being documented, while cancer rates are expected to decline only in the longer term, just because cancer may take several decades to appear after HPV infection.”
Details of the rollout were published in a review of clinical trials of HPV prophylactic vaccines in the Vaccine journal in 2012.
The full potential of HPV vaccination is far from being realised, because despite the development of the vaccine, HPV-related diseases still pose a major public health challenge in developing and developed countries alike. Given the impact it’s having already, even with a low uptake, it’s easy to see that a higher rate of vaccination would have extraordinary results.
Globally more than 600,000 new cancer cases are attributable to HPV every year, and HPV still causes nearly 10% of all new cancers in women worldwide, but that figure is higher in developing countries. The recommendation from the World Health Organisation is that HPV should be included in national immunisation programmes wherever feasible and affordable.
There are a number of hurdles still to overcome, however. “There have been many unfounded claims about adverse reactions, for example,” says Sebati. “However, the vaccine has a positive safety profile – it’s been administered for a decade now, and more than 200-million doses have been administered, so we do know that it’s safe. Those administering the vaccine have to address those concerns with patients upfront, and allay their fears with good, solid evidence.”
Other interventions such as patient reminders generated by healthcare providers could improve uptake of the vaccine, as could integrating HPV vaccination with routine cervical screening, although the vaccine is best administered to children before they are sexually active.
“The vaccine is more effective than expected,” says Sebati, “and it’s great to see how innovations like this vaccine are having a positive effect on public health. The more people who vaccinate their children before sexual debut, the less HPV-related illness and death we will see in the future. That has major positive repercussions for global public health.”