Scientists rush to determine if mutant strain of coronavirus will deepen pandemic

The COVID-19 vaccines rolling out across the nation are lifting spirits over the holidays. But there’s also budding concern about new strains of the virus that have been discovered in Great Britain, South Africa and possibly in Nigeria.  Scientists say they are hopeful, but unsure, that the vaccines will repel the mutants.  Researchers say the U.S. hasn’t done enough to search for mutant strains of the virus and to figure out whether they’ll worsen the pandemic.