The European Union is set to spend more than $10bn (£7.6bn) on hundreds of millions of doses of COVID-19 vaccines developed by Pfizer-BioNTech and CureVac (CVAC), according to reports.

It has secured an agreement to pay €15.50 (£13.88, $18.40) per dose for the vaccine candidate being developed by BioNTech (BNTX) and partner Pfizer (PFE), Reuters first reported, citing an EU official involved in the talks.

The move would mean an overall price of up to €3.1bn for 200 million doses, increasing to €4.65bn if another optional 100 million doses are bought through the deal, the official told the newswire.

The deal, which means that the EU is paying less per dose than the United States, also includes an insurance for countries on the bloc to receive compensation if the companies divert doses to America, the source said.

The EU also confirmed a payment of €10 per dose for a supply of 225 million doses of the coronavirus vaccine candidate from CureVac, a discount from the €12 the German pharmaceutical giant initially set.

It comes after the EU agreed a deal with CureVac for up to 405 million doses, 180 million of which are optional. According to the officials, CureVac had committed to launching deliveries by the end of March, Reuters said.

A spokesperson for BioNTech-Pfizer told Yahoo Finance: “Pfizer and BioNTech are using a tiered pricing formula based on volume and delivery dates. The agreement with the European Commission for the supply of 200m doses, and an option to request an additional 100m, represents the largest initial order of our candidate vaccine to date. We are not disclosing further details of this agreement.”

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READ MORE: EU signs deal to buy 300 million doses of BioNTech-Pfizer COVID-19 vaccine

Pfizer and BioNTech were the first to announce preliminary success with their vaccine, announcing just over a week ago that it had proved to be around 90% effective.

Earlier this week, the companies announced that final data showed their vaccine candidate was now 95% effective against COVID-19, sending European stock markets higher as the news offset lockdown restrictions and rising coronavirus cases.

They said that the vaccine in trials was 94% effective for people over 65-years old, adding that its data indicated their mRNA vaccine works equally well across all ethnicities and races of people. The vaccine is administered in two doses.

Pfizer said there had been "no serious safety concerns" reported. Just 2% of the 43,000 people testing the vaccine said they had experienced a headache, and 3.7% had reported fatigue.

At the time, Dr Albert Bourla, Pfizer chairman and CEO, said: “The study results mark an important step in this historic eight-month journey to bring forward a vaccine capable of helping to end this devastating pandemic. We continue to move at the speed of science to compile all the data collected thus far and share with regulators around the world.”

“With hundreds of thousands of people around the globe infected every day, we urgently need to get a safe and effective vaccine to the world.”

The EU has already signed vaccine purchase agreements with AstraZeneca (AZN.L), Sanofi-GSK (SNY), Janssen Pharmaceutica, and is also in talks with US-based Moderna (MRNA).

Last week Russia also announced that its vaccine in development, called Sputnik V, had shown 92% effectiveness in large-scale trials.

CureVac declined to comment to Yahoo Finance.

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