Moderna's vaccine can be kept at minus 20 degrees Celsius.
London CNN  — 

Moderna became the third Covid-19 vaccine to be authorized for use in the UK, the country’s Department of Health said in a press release on Friday.

The UK’s medicines regulator, the Medicines and Healthcare products Regulatory Agency (MHRA), authorized the vaccine “following months of rigorous clinical trials involving tens of thousands of people and an extensive analysis of the vaccine’s safety, quality and effectiveness,” the Department of Health wrote.

“This is further great news and another weapon in our arsenal to tame this awful disease,” Health Secretary Matt Hancock said in a statement.

The UK government has agreed to purchase an additional 10 million doses of the Moderna vaccine on top of its previous order of 7 million, taking the total to 17 million, the release said.

Supplies will begin to be delivered to the UK from this spring once Moderna expands its production capability, it added.

“We have already vaccinated nearly 1.5 million people across the UK and Moderna’s vaccine will allow us to accelerate our vaccination programme even further once doses become available from the spring,” Hancock said.

Data released in November found the Moderna vaccine was 94.5% effective against coronavirus. The company says its vaccine did not have any serious side effects. A small percentage of those who received it experienced symptoms such as body aches and headaches.

Its results are similar to those of Pfizer/BioNTech’s Covid-19 vaccine because they use the same technique to activate the body’s immune system.

The vaccines deliver messenger RNA, or mRNA, which is a genetic recipe for making the spikes that sit atop the coronavirus. Once injected, the body’s immune system makes antibodies to the spikes. If a vaccinated person is later exposed to the coronavirus, those antibodies should stand at the ready to attack the virus.

Moderna’s vaccine can be kept at minus 20 degrees Celsius. Other vaccines, such as the one against chickenpox, also need to be kept at that temperature.

On Wednesday, the European Commission also authorized the use of the Moderna coronavirus vaccine across the European Union’s 27 member nations, hours after the European Medicines Agency recommended it do so.

CNN’s Elizabeth Cohen contributed to this report.