Nearly three million adults in England remain unvaccinated against Covid, according to the latest figures.
A further 2.7 million people have only had one dose, increasing the risk of severe illness from contracting the virus.
The figures were compiled as part of a report by the Public Accounts Committee, who have urged the NHS to redouble efforts to reach the unvaccinated as Covid cases rise.
Dame Meg Hillier, chair of the Public Accounts Committee, said: “The Department and NHS England must build on the initial successes of the vaccine programme and redouble efforts to reach people who are unvaccinated and at greater risk of becoming hospitalised or dying as a result of Covid-19.
“Despite work to date, low vaccination rates persist in many vulnerable groups and fresh approaches are needed.”
The report states that it is “not yet clear” how NHS England “will strike the right balance” between increasing vaccination rates and limited services available to do so.
Pregnant women are one of the groups with the lowest vaccination uptake. Just 58 per cent had received two doses as of February 2022.
The report also notes that black, black British and Pakistani origins were also less than half as likely to have had their boosters compared to those of white British origin, despite being more vulnerable.
The figures come as Covid infection rates surge across the country, with 2.7 million people in private household estimated to have caught the virus last week.
The Office for National Statistics (ONS), who published the data, said the increase was driven by the spread of the variants BA.4 and BA.5.
A Government spokesperson said: “We are working hard to reach those people who are still unvaccinated against Covid, including using walk-in and mobile vaccination clinics to increase access and convenience, and providing bespoke messages from trusted voices – such as faith and community leaders – to diverse people to get the vaccine.
“NHS England has already begun preparations to ensure they are ready to deploy Covid vaccines to those eligible as part of an autumn Covid booster programme to ensure protection is maintained ahead of winter.”