GPs have been preparing to administer the coronavirus vaccine "by Christmas" if it becomes available.
NHS England boss Sir Simon Stevens said the health service has been preparing to administer any potential Covid-19 vaccine.
He said GPs will be "geared up to start by Christmas if the vaccine becomes available."
He told BBC Radio 4's Today programme: "There are over 200 vaccines in development and we believe that we should hopefully get one or more of those available from the first part of next year.
"In anticipation of that we're also gearing the NHS up to be ready to make a start on administering Covid vaccines before Christmas, if they become available.
"We reached an agreement with GPs to ensure they will be doing that, and we'll be writing to GP practices this week to get them geared up to start by Christmas if the vaccine becomes available."
Sir Stevens also spoke about the situation in hospitals across England, with many hospitals seeing more coronavirus patients now than they did in the first wave.
Sir Stevens said: "These absolutely are desperately sick patients in hospitals.
"In many parts of the country we're now seeing more coronavirus inpatients in hospital and in intensive care than we saw in the first peak in April."
The head of NHS England said the health service is "adding as much capacity as it can" in anticipation of the usual winter pressures and Covid patients.
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But he said people need to do everything they can to keep the infection rates down to ensure that other services - routine operations and cancer care - can be preserved.
He said: "We are obviously adding as much capacity as we can in anticipation of not only coronavirus but the extra winter pressures that always come along with this time of year.
"And the reason we want to try and minimise the number of coronavirus infections and patients is not only because of the excess death rate that implies, but because of the knock-on consequences it has for other services - routine operations, cancer care.
"And so if we want to preserve those other services so that the health service can continue to help the full range of patients, we need to do everything we can, together, to keep the infection rate down for coronavirus."
