American Company Pfizer Inc and German partner BioNTech SE have revealed a breakthrough in a COVID-19 vaccine that prevents 90% of people from catching the disease.

The developers – Pfizer and BioNTech – described it as a “great day for science and humanity”.

Their vaccine has been tested on 43,500 people in six countries including the US, Germany, Brazil, Argentina, South Africa, and Turkey and no safety concerns have been raised.

The companies said they have so far found no serious safety concerns and expect to seek US authorization this month for emergency use of the vaccine for people aged 16 to 85.

Pfizer said the interim analysis was conducted after 94 participants in the trial developed COVID-19, examining how many of them had received the vaccine versus cure.

Pfizer believes it will be able to supply 50 million doses by the end of this year, and around 1.3 billion by the end of 2021.

Two doses, three weeks apart, are needed.

The US paid $1.95 billion for 100 million initial doses of the Pfizer vaccine.