A doctor from Daventry has said she doesn't have enough jabs to vaccinate her town and thinks the government's booster plan has not been well thought out.
Dr Yasmine Darwazeh told ITV Central the aim of completing the process before the end of the year is not realistic.
"I don't think it's achievable - I don't think it is," she said.
"I don't see how the nation can vaccinate 1.1 million people per day by the end of the month, I really don't. I just don't think it's been well thought out.
"We're still waiting on the delivery of the vaccines. We haven't got enough to vaccinate the whole population of our town."
Her comments come as Boris Johnson announced that from today in England, the booster vaccine programme will be opened up to every adult over 18 who has had a second dose of the Covid vaccine at least three months ago.
The NHS booking system will be open to the younger age groups from Wednesday.
Mohammed Kolia, who is the head of vaccinations at Knights Pharmacy, told ITV News Central they should have had longer to prepare.
He said: "We would have appreciated some advanced notice of the announcement so that we could get the workforce into play beforehand."
His comments come as booster vaccine hubs across the West Midlands have spent the morning, preparing for an influx of patients.
One doctor from Leicester has assured people in the Midlands they will be able to get a booster vaccine - insisting the system is a "well-oiled machine".
Dr Abbas Tejani told ITV News Central he is confident it will be possible to achieve the government's goal of offering a jab to all adults in the UK by the end of the year.
But he is concerned about the impact it will have on the rest of the healthcare system.
"The process of the rollout should be fine, we're a well-oiled machine, but the concern is that we were just getting back on top of the backlog of other medical issues and now our attention will be diverted back to Covid," he said.