Moderna says it's working on Covid booster shot for variant in South Africa, says current vaccine provides some protection CNBCBiden to reinstate Covid-19-related travel restrictions lifted by Trump CNNSouth Africa Covid Deaths Likely Higher as Weekly Excess Death Reach Record BloombergBiden to impose travel restrictions on South Africa, U.K. and Brazil to mitigate new Covid strains CNBCModerna says its COVID-19 vaccine protects against new UK and South African variants, but plans to test new booster shot USA TODAYView Full Coverage on Google News