Recent cases in which recovered Covid-19 patients were infected a second time with a new strain also raise the question of how long vaccines might last. Photo: Reuters
Explainer |
Coronavirus vaccine race: where are we and how far?
- Here’s an update on the quest for a magic bullet against Covid-19 that has already killed more than a million people worldwide
- Firms backed by their governments in China, Russia and the US are racing to be the first across the finish line
Recent cases in which recovered Covid-19 patients were infected a second time with a new strain also raise the question of how long vaccines might last. Photo: Reuters
