New Zealand could be sent nearly 250,000 doses of the AstraZeneca-Oxford Covid-19 vaccine before July as part of its deal with an international alliance.
The Covax scheme - which New Zealand joined last year - has released a provisional breakdown of what countries are set to receive. But the final delivery will depend on a range of factors, including regulatory obligations.
The scheme aims to provide vaccine coverage for at least 3 percent of participating countries' population, "enough to protect the most vulnerable groups such as health care workers".
Medsafe has not yet signed off on the AstraZeneca-Oxford vaccine, having only received an application in recent days.
Minister in charge of Covid-19 Response Chris Hipkins said the regulator had been gathering evidence in advance so it could process the application quickly.
He said the approval process would still be carried out thoroughly.
In Covax's first interim distribution forecast, it said sharing this information would aid governments in planning for national vaccination programmes.
However, it warned this forecast was "non-binding and may be subject to change".
"It is likely the distribution may need to be adjusted in light of circumstances that are difficult to anticipate and variables that are constantly evolving."
Final allocations of vaccines would be published "in due course", and only after vaccines are granted WHO Emergency Use Listing (WUL), Covax said.
Three World Health Organisation EUL evaluations are underway in relation to AstraZeneca doses manufactured by AstraZeneca, SK Bioscience, and Serum institute of India.
"The final allocation of the AstraZeneca vaccine(s) will be undertaken following process and governance outlined to and agreed upon by all Facility participants, and will be subject to the validation of the Independent Allocation of Vaccine Group (IAVG)."
Delivery times were also uncertain, depending on "the sequence of countries in the shipment plan, the time taken to place the purchase order, legal / regulatory obligations, as well as the supplier's lead time and related logistics."
"If during this period different products become available, this indicative distribution will need to be adjusted as different products may be allocated to a facility participant and therefore the quantities indicated for the AstraZeneca-Oxford vaccine ... may be altered."
Additional doses of AstraZeneca and Pfizer-BioNTech - which forecast allocations for had also been set out in the document for other countries - will also be available to the international scheme this year, it said.
Yesterday, Medsafe granted provisional approval to the Pfizer-BioNTech vaccine.