CDC director touts progress, but says coronavirus has thrown ‘too many curveballs’ to declare victory

With the coronavirus circulating in other parts of the world, allowing opportunity for more variants to emerge, the prospect of variants is “among the things that keeps me up at night,” she said.

Speaking to a subcommittee of the US Senate Appropriations Committee, which was considering her agency’s budget, she warned of other threats that may also arise in the future.

“Experts have warned for years that a pandemic of this scale was coming, and we must expect additional ... diseases to emerge. We need to ask ourselves: Are we ready?” she said.

Walensky also spoke about the CDC’s recent guidance that vaccinated people can go without masks, either outdoors or indoors, saying the agency had followed the science.

“We moved at the speed science gave us,” she said, noting that new research had confirmed that the vaccines are working in the real world, that they are working against the variants that are currently circulating in the United States, and that they not only prevent illness but transmission of the virus.

“That scientific data was enough for us to move forward,” she said.

She emphasized the agency had issued “individual guidance for people fully vaccinated,” but it was up to local authorities to decide on masking policies, based on local conditions.

“We have really encouraged that the policies of mask-wearing be locally driven. And the reason for that is because every community, every county, has different rates of disease and different rates of vaccination,” she said.

“We really do have to do this at the local level,” she said, warning, “Where there’s less vaccination the virus will emerge.”

Martin Finucane can be reached at martin.finucane@globe.com.