Tonga's Ministry of Health says it plans to vaccinate up to 70 percent of the population by the end of the year.
The COVAX facility, an initiative set up to provide equitable access to vaccines, has put Tonga on the tentative list to receive the AstraZeneca vaccine, which was recently approved by the World Health Organisation.
Chief Executive Officer, Dr Siale 'Akau'ola, said Tonga initially tried to obtain the Pfizer vaccine when it was approved, but it had decided to prioritise countries where people were sick with Covid-19.
Tonga had yet to record a case of the coronavirus.
'Akau'ola said Tonga would receive the AstraZeneca vaccine as it was easier to store and use.
"This is a suitable vaccine for the context of Pacific Islands. The cold chain requirements are similar to what we are familiar with.
"There is no need for any sophisticated cooling system as in the other vaccine and of course the data on its use provided to us is very reassuring, it protects people with severe illness, high percentage of the protective effects it provides and I think as a start for us it's a very good vaccine."
'Akau'ola said he hoped the country could achieve herd immunity while protecting front-line workers, the elderly and those with chronic illnesses.
Tonga does not have ultra-cold storage for the Pfizer vaccine.
The exact amount of vaccine doses will be confirmed once Tonga submits its final National Deployment and Vaccination Plan to COVAX and AstraZeneca.
"There will be two doses - the first vaccine, and then after six or so weeks, the second dose will be administered," 'Akau'ola explained.