Boys and young men should consider being vaccinated against the human papillomavirus (HPV) to protect themselves from a range of illnesses, a conference has heard.
UK girls receive an HPV vaccination to protect them from cervical cancer.
But the Association of Teachers and Lecturers (ATL) wants school sex education to raise awareness that HPV can cause cancers in both sexes.
Boys need information to decide whether to get the jab, the conference heard.
The ATL annual conference, meeting in Liverpool, overwhelmingly backed a motion raising concerns that HPV infection is too often only discussed in the light of the risks of cervical cancer.
"It wasn't until students at my school started questioning why only the girls were being vaccinated that I first started investigating the consequences of this disease.
"What I found was alarming," said Sree Varshini Rajkumar, who proposed the motion.
Ms Rajkumar, from Berkshire, added that NHS statistics indicated that HPV was the second most common sexually transmitted disease in the UK and that 90% of adults would come into contact with at least one strain of the virus.
While the majority of these viruses are benign or harmless, she said, 13 strains "present a very high risk of developing into cancers".
"The human papilloma virus directly causes 7,084 cancers in the UK each year", she said.
'Duty of care'
She cited figures from the charity, HPV Action, that the virus caused more than 1,400 cancers of the head and neck in British men in 2011, "not to mention the 600 cases of HPV-related anal and penile cancers that are diagnosed every year as well".
"As educators we have a duty of care to the young men in our schools to provide them with the information that they need to choose to get vaccinated," said Ms Rajkumar.
She said men who had sex with men were particularly vulnerable "and they receive no protection from the vaccination of our girls".
Seconding the motion, Helen Porter, also from Berkshire, pointed out that the guidance for the teaching of sex and relationships education in schools was in urgent need of updating "having received no modifications since the year 2000".
"Safe oral sex is not widely discussed in education settings but many sexually transmitted infections, including chlamydia, syphilis, HIV and HPV can be transmitted this way," said Ms Porter.
She said updated sex and relationships education should include advice on the use of barrier methods during oral sex, such as condoms and dental dams which are thin latex sheets which act as a protective barrier.
The vote commits the ATL to working to raise awareness of the wider risks of HPV and of the need to use protection during oral sex and to lobby for updated classroom resources and official guidelines on age appropriate sex and relationships education in schools.
Last month, Education Secretary Justine Greening announced that sex and relationships education would become compulsory in all of England's secondary schools from 2019.
The HPV vaccination is available privately to men and boys and costs between £300 and £450.
Tom Kallis a pharmacist with high street chemists Boots, which offers the service in some stores, said: "The HPV virus is very common and easily spread by sexual activity, which is why we advise both boys and girls to be vaccinated before becoming sexually active."