Health chiefs say they will now begin offering vaccinations for congenital rubella in September next year instead of next month, the HPA has confirmed.
The delay follows tests that some babies may have been exposed to the virus but escaped vaccinations.
It is also confirmed to mean that the seasonal seasonal vaccinations for children will not be as effective as expected.
The HPA said it was encouraging parents to be vaccinated as soon as possible.
It said it would no longer delay vaccinations for those that had been protected in previous years.
The HPA said: “The vaccine is safe and effective but when the risks and benefits were reassessed last week, the impacts of not administering the vaccine or giving it too late became more apparent than those of both the vaccine and the reassessment itself.
“We are therefore recommending that healthcare professionals and parents defer administering the vaccine to young children until September 2019.
“Additionally, as a result of reassessment, and as a further reassurance, the HPA will be recommending to healthcare professionals to cancel vaccinations for infants who are not protected by the national rubella vaccination programme as soon as possible.”
The first season of the seasonal vaccination series for children for 2019 ended at the end of October.
But the HPA said the vaccine was still effective.
Rubella is a viral infection of rubella virus that can lead to mild or, in some cases, severe complications.
The vaccine is available in the UK via the national rubella vaccination programme.
This involves women having a highly effective jab during pregnancy to help prevent their babies catching the virus.