Four coronaviruses already circulate in human beings. They cause common cold symptoms and we don’t have vaccines for any of them.
Most experts think a COVID 19 vaccine is likely to become widely available by mid-2021,
Trials need to show the vaccine is safe. It would not be useful if it caused more problems than the disease itself
Clinical trials will also need to show vaccines provoke an immune response, which protects people from getting sick.
The first human trial data back in May indicated the first eight patients taking part in a US study all produced antibodies that could neutralize the virus.
A group in China showed a vaccine was safe and led to protective antibodies being made. Russia’s first potential vaccine would be approved by regulators this month. Russia plans wider vaccinations for October.
Trials of the vaccine developed by Oxford University show it can trigger an immune response and a deal has been signed with AstraZeneca to supply 100 million doses in the UK alone.
