Vaccine could eliminate varicella virus
By Lilian Anekwe
A two-dose vaccination programme could eliminate the varicella virus in the UK, but may also mean the elderly need to be vaccinated to prevent them contracting shingles, according to new research.
Modelling data from Health Protection Agency researchers found that a two-dose schedule, at the levels of coverage likely to be achieved in the UK, would eliminate varicella in children included in a possible vaccination programme.
But there is a suggestion the reduction in varicella after a successful vaccination programme would result in less boosting of specific immunity in adults.
This would resulting in an increased incidence of herpes zoster, and shingles, in adults unexposed to varicella in children.
Researchers modelled the impact of vaccination on the incidence of chickenpox and shingles, and found vaccination against both diseases would lower the incidence of infection with the varicella zoster virus.
Study leader Dr Albert Jan van Hoek concluded: ‘With a two-dose schedule at the levels of coverage likely to be achieved in the UK, the model predicts that varicella might be eliminated.
‘However, this may lead to an increase of zoster in the medium term. This increase can be partly offset by vaccinating the elderly against herpes zoster. A part of the raise can be prevented by vaccinating the elderly.'
The Government's Joint Committee on Vaccination and Immunisation is currently assessing evidence on whether vaccinating children against chickenpox would be cost-effective, and if so in which age group. A vaccine to prevent chickenpox was introduced in the US in 1996.
The research will be presented at the Health Protection Conference 2008 later this month.