The HPV vaccine, which is currently given to young girls in Ireland to prevent cervical cancer, should be given to young boys as well, experts have said.
HPV (human papilloma virus) is a group of more than 100 viruses. HPV infection is very common - in fact, it is the most common sexually transmitted infection (STI) worldwide. Most HPV infections have no noticeable symptoms and over 90% are cleared by the body's immune system. However, some people will develop infections that need treatment.
In women, HPV infections can lead to abnormal changes in the cervix, which if left untreated, can lead to cervical cancer. The provision of the vaccine to girls in their first year of secondary school has been in place here since 2010.
However, a new study by scientists at Trinity College Dublin (TCD) and St James's Hospital has found a high rate of cancer-associated HPV infections in men who have sex with men. These infections would be preventable if the HPV vaccine was provided to males.
According to their findings, the incidence of HPV-associated anal cancer is on the increase. Furthermore, men who have sex with men, especially those who already have HIV, are ‘disproportionately affected'.
Meanwhile, HPV now also accounts for around one in five cases of head, neck and throat cancers in Ireland and this figure is rising.
This latest study, which looked at men who have sex with men, half of whom had HIV, revealed that 69% were infected with HPV. At least one in four of these had a specific type of HPV, known as HPV type 16, which has been linked to over 80% of anal cancers.
"Our study highlights the burden of anal HPV infection in men who have sex with men and those with HIV co-infection. A significant proportion of participants in our study did not have evidence of current infection with HR-HPV types 16 or 18, which are the HPV types most commonly associated with anal cancer. This indicates that a large proportion could benefit from HPV vaccination," noted the study's principal investigator, Prof Colm Bergin, of TCD.
Also commenting on the findings, the study's lead author, Dr Corinna Sadlier, of TCD, pointed out that the National Immunisation Advisory Committee recently recommended that the HPV vaccine be made available for males and females with immune-compromising conditions, such as HIV.
It also stated that the HPV vaccine should be considered for men who have sex with men up to the age of 26 years, and boys aged nine to 26 years.
"The greatest benefit of the HPV vaccine has been demonstrated prior to sexual debut. Universal vaccination of boys and girls, as is offered in the US and Australia, is the ideal. While we await guidance on provision of HPV vaccine for boys, this data would support provision of targeted vaccination of high risk groups.
"Public Health and national policy maker support is needed if these guidelines are to be implemented and if this new information is to be integrated into national policy,' she said.
Details of this study are published in the journal, HIV Medicine.