Explainer | How the coronavirus vaccines compare and who can get them
- The race to carry out the biggest inoculation programme in history has begun, with six products approved and more to follow
- What are some of the differences between the various vaccines and how many doses have been ordered around the world?

Here is a snapshot of the situation so far, from vaccine development to distribution, and some answers to frequently asked questions about how they work.
How many vaccines?
National health agencies are reviewing and granting emergency use authorisations to a number of vaccines developed by different pharmaceutical companies and mass inoculation programmes are rolling out in many countries.
Six have been approved so far, using different technologies and with varying side effects. They have been developed by: US firm Moderna; US-German partnership Pfizer-BioNTech; Britain’s Oxford-AstraZeneca partnership; Sinopharm and Sinovac in China; and Russia’s Gamaleya.
According to WHO guidelines, health authorities should continue to monitor for any side effects after mass inoculation starts.