Only time will tell

Unlike therapeutic drugs, the benefits of a new vaccine can be very slow to materialise. This month sees the start of a programme in the UK to vaccinate all schoolgirls against HPV with the aim of eventually reducing the number of deaths from cervical cancer - the second most common cancer in British women. All girls aged between 12 and 17 should have been offered the vaccine by August next year.

As with the introduction of any national healthcare programme - and particularly in view of the unjustified suspicions concerning the MMR vaccine - the HPV vaccine programme is not without controversy.

The chief concern among parents seems to be that the vaccination will encourage their daughters to engage in sexual activity for which they are not emotionally or physically ready.

Doubts have also been cast on the effectiveness of the vaccines. Recently an article in the New England Journal of Medicine said that more long-term studies were needed before large-scale national vaccination programmes could be recommended.

A number of key questions remain unanswered, the journal says, including the issue of the vaccine preventing not only cervical lesions but also cervical cancer, the length of time vaccination affords protection and the effect it might have on natural immunity against HPV.

And then there is the question of cost. Without long-term studies, it is very difficult to calculate whether vaccination is more effective than the current screening programme, especially if the protection afforded by the vaccine turns out not to be life-long.

Nor are the vaccines guaranteed to be free of side-effects. Australian doctors writing in the Canadian Medical Association Journal have pointed to the possible association of Gardasil with higher than expected risk of anaphylaxis following vaccination.

Key to the success of the programme will be an information campaign to enable parents of the target group to make a decision based on fact rather than media hype. But by an unfortunate accident of timing, the launch of the vaccination programme coincided with the cervical cancer diagnosis of a former UK reality television "celebrity".

This will probably raise the profile of the vaccine debate to levels that would have been hard to achieve by any other means. In this case, any and all publicity is probably a good thing.