As new coronavirus strains emerge and infect more people, questions loom over vaccine effectiveness.
Vaccines appear to be less effective on the variant found in South Africa, which includes the E484K mutation [Siphiwe Sibeko/Reuters]
SARS-CoV-2, the virus that causes COVID-19, keeps changing, generating new and more transmissible versions as the world scrambles to stay ahead of a pandemic that has killed more than 2.3 million people so far.
First, a variant was detected in the United Kingdom, causing an explosion of new cases, then two more emerged in South Africa and Brazil, raising questions over whether vaccines would be effective against these mutations.
Here is what you need to know:
The first variant was first detected with 23 mutations in