A small study of people hospitalized during the current outbreak of the Omicron variant of coronavirus in South Africa found a pattern of milder illness than in previous waves of Covid-19, though the authors, and scientists more broadly, cautioned that it is too early to say for sure if the new fast-spreading strain is less virulent than its predecessors.

In the U.S., federal regulators said Sunday that the Food and Drug Administration is already in conversations about streamlining authorization of revamped vaccines if necessary in response to the new variant. “The FDA will move swiftly and CDC will move swiftly after,” Centers for Disease Control and Prevention Director Rochelle Walensky said on ABC’s “This Week with George Stephanopoulos,” adding that “we’re everyday hearing about more and more cases.”