About 280 general practices within the Hunter New England and Central Coast Primary Health Network have been approved to begin administering the AstraZeneca vaccine from Monday.

But practices say the phone has been "ringing off the hook" with vaccine inquiries while juggling glitches with the national booking system and concerns about vaccine availability.

"We had four administration staff who spent the entire day declining vaccination appointments due vaccine unavailability," Dr Ben Seckold, of Hamilton Doctors, said on Wednesday.

"It is absolute chaos. Ten phone lines have been in use all day, and 90 per cent of calls are not regular patients."

In a joint statement, the Royal Australian College of General Practitioners (RACGP) and Australian Medical Association (AMA) said the rollout of the vaccine was a "huge logistical challenge" constrained by the available supply.

Australia's peak GP bodies said the influx of patients seeking to make bookings for COVID-19 vaccinations was encouraging, but the government must "urgently clarify" the booking process for patients to help them better understand the process.

"Based on the volume of calls GPs have already received today, it's good to see that the community is confident and wants to access a COVID-19 vaccination," AMA President, Dr Omar Khorshid, said.

"However, it's clear the government needs to make it easy for patients and general practices alike to manage bookings for COVID-19 vaccinations and be clear about how long patients may have to wait before they can get an appointment."

Dr Khorshid said the rollout of the vaccine in general practice would start slowly and then build over time.

"Unlike the flu season, where 15 million doses are already stockpiled, this rollout relies on a weekly supply of COVID-19 vaccine doses that is capped," he said.

"This means that general practices will have only a modest number of doses available for patients for now.

"GPs will be following strict priority criteria to ensure that vaccines are prioritised towards those who need it most. This is a time for patience for everyone involved."

More to come.