Is your child getting the HPV vaccine at school this year?

The clinical trials that established the vaccine’s efficacy in reducing early cervical changes did not study children at the age at which the vaccine is now routinely given in schools.

Across much of the world, the HPV vaccine is delivered through school-based programmes to children aged 11 to 13.

The policy is presented as straightforward: vaccinate early to prevent cervical cancer later in life.

It’s a message that suggests the policy rests on rigorous evidence.

But the clinical trials that established the vaccine’s efficacy in reducing early cervical changes did not study children at the age for which the vaccine is now routinely recommended.

That detail is rarely explained in public messaging — or to parents consenting to their children lining up for the vaccine at school.

To understand how this happened, it is necessary to look closely at the trials that first established the vaccine’s efficacy.

What did they measure? Who did they enrol? And how did those findings become the basis for recommending HPV vaccination for millions of schoolchildren around the world?