NHS England has said it will increase efforts to stem the fall in vaccination rates after a National Audit Office (NOA) report criticised inconsistencies in the current system.
The study found that the 95% take-up target for six out of seven pre-school jabs had been missed in 2018/19.
The 95% immunisation benchmark is set to produce so-called herd immunity which arises when a high percentage of the population is protected through vaccination against a virus or bacteria, making it difficult for a disease to spread because there are so few susceptible people left to infect.
Two doses by the age of five of the Measles, Mumps and Rubella (MMR) jab are needed to provide immunity, but currently only 86.4% of children are having the second injection. In some areas of London the rate is as low as 67%.
Meanwhile, the Hib/MenC booster (to protect against the potentially fatal haemophilus influenzae type B and meningitis C) at ages two and five has never exceeded 95% and continues to fall.
The NOA report found vaccination rates for young children had been falling since 2012/13 with reasons including timing and availability of GP appointments and parents needing childcare, as well as families moving from area to area with “no consistent system” for calling or recalling children.
However it found “limited evidence of any major impact on vaccination uptake rates” from anti-vaccination messages on social media.
Outlining what it believed to be the main reasons for falling rates it said: “When primary care trusts were abolished in 2013, NHS England took responsibility for commissioning call/recall.
“NHS England has not set out requirements of GPs for call/recall under the changed arrangements.
“As a result, call/recall is done inconsistently and there is no coherent system.
The report said children are called for vaccines to “varying extent by GP practices” and also by regional Child Health Information Services (CHIS).
But while NHS England checks how call and recall is handled by CHIS, it does not review the work done by GPs.
The Royal College of GPs said the system for notifying patients when jabs were due was done on a practice-by-practice basis and agreed with the NAO that a more standardised approach would be a sensible measure to consider.
Responding to the study, NHS England said it would introduce a consistent way of reminding people to attend vaccinations, although the details have not yet been agreed with family doctors.
It said it also intends to increase the cash given to GPs for ensuring children have MMR, and working to create networks of GP surgeries which could mean more appointments in the evenings and on weekends.
Professor Stephen Powis, NHS medical director said: “One of the most effective, cheap and essential tools for keeping us all safe is a simple, free jab – it can save the life of your child.
“Looking at ways to expand access to appointments will make it even easier for parents to protect their children.
“It is vital that everyone takes up this lifesaving opportunity and isn’t swayed by the dangerous marketing of false information by anti-vaxxers.”
The NOA report comes after Health Secretary Matt Hancock said last month that he is seriously considering mandatory vaccination for children to try to combat falling rates.