Evidence showing that the measles vaccine isn't working continues to mount. An epidemic of measles has been reported in Israel, and there has been an outbreak in 31 schools in Canada.

The Canadian study also shows that babies vaccinated before one year were at greatest risk from developing measles.

While the recommended age for the first vaccine is 15 months, this new finding is bad news for those lobbying to bring forward the administration of that first jab.

The measles epidemic in Israel is worrying health officials. Nearly 1000 cases have so far been reported this year, despite an immunization programme that, while voluntary, still covers about 90 per cent of young children in the target group.

The measles-mumps-rubella vaccine replaced the measles vaccine in 1988. The age to receive the first vaccine was lowered during the current epidemic from 15 to 12 months. The last major Israeli outbreak occurred in 1991 during the Gulf War (The Lancet, 28 May, 1994).

The outbreak in schools in Ontario, Canada was discovered during a study to evaluate the effectiveness of the vaccine.

Investigators found 87 vaccinated children had gone on to develop the illness; those who had been vaccinated before one year of age were at greatest risk of developing measles later.

Overall, researchers concluded that children need to receive at least two jabs over a few years to improve their chances of avoiding measles (JAMA, 25 May, 1994).

A further study, from South Africa, also endorses earlier concerns that the Edmonston Zagreb (EZ) measles vaccine is more likely to cause death among girls (The Lancet, 28 May, 1994).