What Is Human Papillomavirus and How Does It Affect the Body?
HPV is a group of more than 200 related viruses spread through skin-to-skin contact, most commonly during sexual activity. Most people will carry at least one strain of HPV at some point in their lives without knowing it, since the infection produces no symptoms in the majority of cases.
In most people, the immune system clears the virus naturally within 1 to 2 years. But when high-risk strains like HPV 16 or 18 persist, they can cause abnormal cell changes in the cervix, throat, anus, penis, vulva or vagina that, over years, may develop into cancer.
Low-risk strains such as types 6 and 11 do not cause cancer but are responsible for genital warts, which are one of the most commonly diagnosed sexually transmitted infections in the UK.
Importance of HPV Vaccines
HPV vaccination is one of the most effective cancer-prevention tools available in primary care. Public Health England’s data consistently shows that the NHS school programme has cut the rates of high-grade cervical abnormalities in vaccinated cohorts by over 85%.
For adults who missed the school programme or were not eligible for NHS vaccination, private vaccination closes that gap. The vaccine has a strong safety record built on over two decades of post-market surveillance across more than 130 countries.
Who Is at Risk of HPV?
HPV is not limited to any one group. The virus spreads through genital skin-to-skin contact, which means penetrative sex is not required for transmission.
You are at higher risk if you:
- Have had more than one sexual partner (or your partner has)
- Have a weakened immune system due to illness or medication
- Missed or only partially completed the NHS school vaccination programme
- Are a man who has sex with men (MSM), a group that does not benefit from herd immunity from the female school programme
- Are a sex worker or in contact with sex workers
Age at first vaccination matters. The vaccine works best before any HPV exposure, so earlier is better, but it still offers meaningful protection in older adults who have not been exposed to all covered strains.
Who Shouldn’t Take the HPV Vaccine
Gardasil 9 is safe for most people, but there are situations where we will defer or not administer the vaccine.
We will not administer the vaccine if you:
- Have a confirmed severe allergy (anaphylaxis) to a previous dose of Gardasil or any of its components, including yeast
- Are currently unwell with a fever above 38°C (mild illness or a cold is not a reason to postpone)
We will defer the vaccine and advise you to discuss with your GP or specialist if you:
- Are pregnant or think you may be pregnant (vaccination should wait until after delivery)
- Are severely immunocompromised and have not confirmed with your specialist whether to proceed
- Have a bleeding disorder that makes intramuscular injection a risk
If you are breastfeeding, Gardasil 9 is considered safe, but let us know so we can document it properly.
