GPs are too busy to administer booster jabs without extra support, the head of the Royal College has warned, as ministers promise rollout plans within weeks.
Health officials have said third doses could be administered as soon as September, along with flu jabs, with the elderly likely to be targeted first.
On Monday, health service leaders said annual jabs might be needed for a decade, and called for urgent decisions about how the programme will operate.
Professor Martin Marshall, chairman of the Royal College of GPs, said any programme would need extra resources, including staff other than doctors and nurses.
He told BBC Radio 4’s Today programme: "We do need to (look) into what the programme looks like for an endemic condition, when we’re outside the crisis mode that we’ve been in the last six months.”
He added: "In general practice – where three-quarters of the vaccines have been given – our GPs and nurses are extremely busy. Is it possible that a booster campaign can be given by non-clinical trained vaccination staff?"
Prof Marshall said GPs should remain involved in the rollout, but said: “It needs to be adequately resourced to allow us to do it well. We can’t have GPs and practice nurses and pharmacists diverted away from normal business, because we can’t afford to let our patients down on all the many other things that we do in general practice."
On Monday, Matt Hancock, the Health Secretary, said ministers are waiting for the results from trials of different vaccines before the plans are agreed, promising to set out all the details “in the next few weeks”.
Health officials have already said that the booster jabs could be administered alongside flu jabs this autumn.
On Monday, Chris Hopson, the head of NHS Providers, told Times Radio: "Flu jabs start in September, so if we’re going to do one jab in one arm, one jab in the other, we really do need to know quite quickly."
He said Covid-19 vaccines were "probably" going to be needed on "an annual basis for, I don’t know, at least five, six, seven, eight, nine, 10 years".
Seven vaccines are currently being tested in the Cov-Boost trial to see which could be used in any forthcoming autumn vaccination programme.
Where in the UK vaccine booster trials will take place and what vaccines are being considered
Researchers believe that all seven vaccines will boost immunity, and lab studies are checking their response to variants circulating in the UK, including those first identified in India, Kent and South Africa.
The £19.3 million UK clinical trial is testing the Pfizer jab alongside those from AstraZeneca, Moderna, Novavax, Janssen from Johnson & Johnson, Valneva and CureVac.
The study will examine questions such as whether people who have had two doses of AstraZeneca may get more benefit from a third dose of Pfizer.
"When we know the results of that (trial), then we will set out the full plans for the booster programme over the autumn," Mr Hancock told BBC Breakfast on Monday.
"We’ve got to make sure we get the logistics right; for instance, GPs have been so heavily involved in this vaccination effort, but GPs have also got to do their day job, so that’s something we’re working hard on now and, in the next few weeks, when we get the clinical data through on what’s the most effective combinations to have… then we’ll set out all the details of the booster programme for the autumn."
Latest UK vaccine numbers: rollout figures
Professor Saul Faust, lead investigator of the booster vaccine trial, said his team would be able to provide data to the Joint Committee on Vaccination and Immunisation (JCVI) by the "end of August".
Last week, Professor Sir Andrew Pollard, head of the Oxford Vaccine Group, told MPs "we have absolutely no evidence that there is a need for a third dose" at the moment.
He said the UK was seeing "very high levels of protection against hospitalisation with two doses" using current vaccines and it was too early to say when protection would wane.