//EXPLAINER: Are new coronavirus strains cause for concern?

EXPLAINER: Are new coronavirus strains cause for concern?

Reports from Britain and South Africa of new coronavirus strains that seem to spread more easily are causing alarm, but virus experts say it’s unclear if that’s the case or whether they pose any concern for vaccines or cause more severe disease. Viruses naturally evolve as they move through the population, some more than others. It’s one reason we need a fresh flu shot each