The first Covid-19 vaccine has been announced by German pharmaceutical company Pfizer, which says it could offer 90 per cent protection from the virus. 

Potentially available within weeks the companies developing the vaccine plan to apply for emergency approval to use the vaccine by the end of the month. 

The firm, which is developing the mRNA-based vaccine with BioNTech, said: "Today is a great day for science and humanity.” 

The vaccine has been tested on 43,500 people and no safety concerns have been raised. 

How does it work?

The experimental vaccine is in the final stages of testing and involves injecting the patient with part of the virus’s genetic code in order to train your immune system. 

Two doses are needed three weeks apart and the trials from six countries show that a 90 per cent protection rate has been achieved seven days after the first dose. 

When will it be available?

Pfizer believes there will be 5 million doses available by the end of the year, with 1.3billion by next year. 

The UK has already ordered 30 million doses, although there are some logistical challenges as the vaccine must be stored below minus 80C.

Dr Albert Bourla, Pfizer chairman and CEO, said: “With today’s news, we are a significant step closer to providing people around the world with a much-needed breakthrough to help bring an end to this global health crisis.”