Girls aged 12 will be inoculated from today in a nationwide schools programme against a virus that can cause cervical cancer. Many are expected to boycott the jabs, however, because parents are fearful of vaccines after the MMR controversy.

The Government began an advertising campaign yesterday to raise awareness. Some families complained, though, that they had received too little information too late to make a decision. In a trial last year a fifth of parents refused permission for their daughters to have the injection.

About 600,000 girls will be vaccinated initially, followed by a catch-up programme for older teenagers. It will give protection against strains of the human papilloma virus (HPV), considered to be responsible for 70 per cent of cases of cervical cancer, which kills more than 1,000 women a year in Britain.

Recent criticism of the Government over its choice of vaccine, Cervarix, has fuelled debate. Although most parents appear to be in favour of inoculation, some are concerned that Cervarix has not been tested sufficiently, while others have been scared by stories claiming that girls have suffered extreme reactions to a similar drug in America. A few are worried that vaccinated girls will be less likely to have smear tests and more inclined to have sex at a young age. A third of those who did not allow their daughters to take part in the pilot study in Manchester gave long-term safety as the reason.

Margaret Morrissey, of the National Confederation of Parent Teachers Associations, said too few people knew about the new programme: "There certainly hasn't been any parent consultation with organisations, as far as I'm aware."

Jabs, an advisory group that aims to promote understanding about immunisations, has been contacted by anxious parents about the cervical cancer programme. Its spokeswoman, Jackie Fletcher, said: "There is a number of questions we want answered, such as how will the vaccine affect prepubescent girls? There have been only very limited trials. A large number of adverse reactions was reported in the US for the drug they use, such as collapsing, seizures and paralysis."