As Covid Vaccine Nears, There Are Reasons for Hope and Caution

Sign up here for our daily coronavirus newsletter on what you need to know, and subscribe to our Covid-19 podcast for the latest news and analysis.

Thousands of researchers in more than 30 countries have been collaborating and competing this year on more than 200 projects to develop a vaccine against the novel coronavirus in record time. In the most encouraging scientific advances so far, two vaccines have delivered positive news that their shots were more than 90% effective in late-stage trials. However, a number of hurdles still need to be cleared, and testing that was halted on other promising candidates highlighted the uncertainties and risks that developers face. With the best hopes for ending the pandemic resting on the global deployment of an effective vaccine, the stakes are immense.