The controversial human papillomavirus (HPV) vaccine does not cause fertility problems and may actually improve chances of conception in some women, according to new research.
HPV infection, which is spread during sexual intercourse, has been linked with – although not conclusively proven – causing reduced semen quality and lower pregnancy rates.
There is also public concern about whether the vaccine safeguarding against it that is given to teenage girls could affect their fertility in the future.
Now, a Boston, US, study, the first of its kind, has shown little overall link between HPV vaccination and the chances of conceiving for men and women – except among women with a history of sexually transmitted infections (STIs).
STIs are associated with lower fertility, but vaccinated women with an STI history had about the same chance of becoming pregnant as unvaccinated women who had never had an STI.
Therefore, the researchers have concluded that the vaccine had a protective effect.
New research has shown no link between HPV vaccination and infertility (stock photo)
‘Our study found no adverse effects of HPV vaccination on fertility and indicated that it may, in fact, protect fertility among individuals who have had other STIs,’ said study author and Boston University School of Public Health (BUSPH) researcher Kathryn McInerney.
‘Our study should reassure those who are hesitant to vaccinate due to fertility concerns.’
The research, published in the journal Paediatric and Perinatal Epidemiology, was based on an analysis of data from an ongoing study which enrolled 3,483 women and 1,022 men aged 21 to 45 years who were actively trying to conceive.
Couples were followed for 12 months or until pregnancy, whichever came first. At enrollment, 33.9 percent of women had been vaccinated against HPV, compared to 5.2 percent of men.
Why has HPV been linked to fertility problems?
HPV is so common that nearly all sexually active men and women get the virus at some point in their lives, according to the Centers for Disease Control and Prevention.
In most cases, it goes away on its own and does not cause any health problems. But for some people it causes cancer for reasons that are not fully understood.
Having HPV can increase your risk of cervical cancer and removing cancerous or precancerous cells from your cervix can reduce fertility.
And according to an article by Italian researchers in the journal Human Reproduction in 2012, ‘HPV infection is associated with an impairment of sperm parameters, suggesting a possible role in male infertility.’
Vaccine controversy
In 2013, two Wisconsin sisters filed a federal claim, saying they believe a HPV vaccine caused their ovaries to stop producing eggs.
Madelyne Meylor, 20, and Olivia Meylor, 19, claimed their condition came from the Gardasil brand. However, a federal judge dismissed the claims.
In the US, both boys and girls are supposed to get two or three doses of the vaccine, starting at age 11 or 12. More than 40 percent of American teens are now getting vaccinated according to the BUSPH researchers.
In the UK, the vaccination is currently given to girls aged 12 to 13 on the NHS but – controversially – not boys. Uptake in adolescent girls is consistently high – over 85 per cent – according to Mary Ramsay, head of immunisation at Public Health England.
BUSPH researchers believe their findings should reassure those concerned about a link between the jab and infertility.
‘Internationally, parents have chosen not to vaccinate their children due to concerns about the vaccine’s effect on future fertility,’ said Ms McInerney.
‘We hope this study will be useful for health providers who counsel individuals and families about HPV vaccination.’