The campaign, in which Public Health England and NHS England will work together, was provoked by the recent outbreak of measles in Swansea.
Most of the children targeted are aged 11–16, a group made vulnerable by a steep decline in uptake of the MMR vaccine following the publication of a medical paper in 1998 claiming it was linked to autism.
The paper has since been exposed as fraudulent, though its claims are still supported by some anti-NHS tabloids.
In the mid-1990s, measles had almost been eradicated in the UK. But by the year 2000, uptake of the MMR vaccine had dropped to 80%, allowing the virus to circulate widely.
In 2012, there were nearly 2,000 cases of measles in England – the highest level in two decades. This year, an outbreak in Wales has infected over 900 people.
The million children in England targeted by the new NHS campaign form three similar-sized groups: children aged 11–16 who have received no vaccine; children aged 11–16 who have received one vaccine dose without the ‘booster’ jab; and children in other age groups who lack protection.
Local area teams will use general practice case registers to identify children at risk and ensure their vaccination in schools and GP surgeries.
Mary Ramsay, Head of Immunisation at Public Health England, said that although take-up of the MMR vaccine had returned to a high level, there was a “legacy of under-vaccinated children” who needed protection.
MMR vaccines, which protect against measles, mumps and rubella, are available from GSK and Sanofi Pasteur MSD.