Moderna Starts Human Tests of South Africa Variant Covid Shot

Moderna Inc.'s experimental booster shot to protect against the Covid-19 variant first identified in South Africa has moved into human testing, the NIH announced Wednesday.

The trial, which the the National Institute of Allergy and Infectious Diseases is leading and funding at four sites across the U.S., comes as nine states have identified the B.1.351 variant of the SARS-Cov-2 virus in patients.

Moderna’s vaccine, authorized in December, appears to protect against Covid variants that have developed over the past several months. Its overall high protection level (94%) makes it effective—although perhaps not as effective—against different versions of the virus.

“However, ...