Vaccination against rubella in Britain: benefits and risks.

The benefits and risks of rubella vaccine differ with the programme of vaccination adopted. Programmes in which vaccine is primarily administered to girls aged 11 to 13 years are slow in achieving effects on the incidence of congenital rubella because of the 10 year delay between vaccination and peak child-bearing. In Britain an increase in the percentage of women rubella antibody seropositive and a fall in the numbers of pregnancies terminated for rubella have occurred following the introduction of vaccination for 13 year old girls in 1970. The majority of women will continue to be protected by the sturdy immunity elicited by natural infection occurring before vaccination. Programmes which vaccinate boys and girls before school entry aim to shield pregnant women from infection and are more rapid in effects. However, in such populations immunity becomes predominantly vaccine induced, while vaccination at an earlier age requires the immunity to be more durable. In general, reactions to rubella vaccine increase with the age of the vaccine. Nevertheless, there are few significant reactions to vaccine and for the individual vaccinee the risks of vaccination are low.