JOHANNESBURG, SOUTH AFRICA -- South Africa will buy doses of Oxford-AstraZeneca's COVID-19 vaccine at a price 2.5 times higher than most European countries, the health ministry said Thursday.

The continent's worst virus-hit country has ordered at least 1.5 million shots of the vaccine from the Serum Institute of India, expected in January and February.

A senior health official on Thursday told AFP those doses would cost $5.25 (4.32 euros) each -- nearly 2.5 times the amount paid by most European countries.

"The National Department of Health confirms that the price $5.25 is what was quoted to us," deputy director-general of health Anban Pillay said via text message, without explaining the price difference.

European Union (EU) members will pay just 1.78 euros (US$2.16) for AstraZeneca's shots, according to information leaked by a Belgian minister on Twitter last month.

Bilateral deals between wealthier governments and coronavirus vaccine manufacturers have raised concern over price hikes and lack of supply for low- and middle-income countries.

The World Health Organization last year warned against "vaccine nationalism" and "price gouging" once a successful shot was found.

AstraZeneca France told AFP in November that its shots would be capped at 2.5 euros (around $3) per dose "to provide vaccines to the widest population, with as fair access as possible."   

The pharmaceutical giant did not immediately respond to requests for comment on the health ministry's price quote.

South Africa's AstraZeneca vaccine order is part of 20 million secured doses to be delivered in the first half of 2021.    

The WHO-backed Covax facility is expected to provide shots for 10 per cent of the population between April and June.

Other vaccines will be provided via the African Union and bilateral contracts with suppliers that have not yet been disclosed. 

Opposition groups have meanwhile criticised South Africa's inoculation strategy.

"Reports today indicate that... government will have to spend double what some other countries are paying for their vaccines," the main opposition Democratic Alliance party said Thursday, blaming poor planning and delayed negotiations.

Trade union Solidarity and prominent rights group Afriforum jointly announced plans to launch a legal battle against the government over lack of transparency.

"The government's non-disclosure of information is further proof why it cannot be trusted with a monopoly regarding the purchasing and distribution of COVID-19 vaccines," Afriforum said in a statement on Thursday.

South Africa is battling with a second wave of infections fuelled by a new coronavirus variant deemed more infectious by scientists.

To date the country has recorded over 1.3 million cases and 38,800 deaths.

The government aims to vaccinate two thirds of its population -- around 40 million out of nearly 60 million people -- to achieve herd immunity by the end of 2021.