DR JOIA MUKHERJEE, the chief medical officer at Partners in Health, said the organization has drastically scaled back its contact tracing workforce amid a sharp decline in COVID-19 infections.

On CommonWealth’s Health or Consequences Codcast, Mukherjee said Partners in Health has gone from 1,900 employees to 470. Working under a contract with the state of Massachusetts, the organization contacts those infected with the coronavirus and tracks down all those who they have come in close contact with (within 6 feet for at least 15 minutes) to urge them to get tested and quarantine. The program also employs resource coordinators to help those who need food, health care, or other services in order to shelter and recover or quarantine.

Mukherjee said the organization is now right-sized for the job it needs to do. “We think that will allow us to properly handle 300 cases a day in addition to what the local boards of health are handling,” Mukherjee told John McDonough of the Harvard TH Chan School of Public Health and Paul Hattis, recently retired from the Tufts University Medical School.

State officials have been vague about the employee reductions at Partners in Health. As of June 18, a spokesman said the nonprofit had 1,212 employees, which was described as “peak staffing.” If those numbers were accurate, the nonprofit cut 742 employees in about 15 days.

Despite the dramatic downsizing, Mukherjee said the organization will probably have to grow again in the future to cope with a second surge of cases. “I think in Massachusetts we will see a second wave,” she said. “There is still a virus circulating in our community.”

Mukherjee praised Gov. Charlie Baker for hiring Partners in Health and launching the state’s large-scale contact tracing effort. She said the only way to stop the spread of the disease is through an aggressive program to track down the contacts of those infected and give them the help they need to prevent the spread of the disease.

Initially, the effort was connecting with only 40 to 50 percent of contacts, but Mukherjee said the percentage is now up to 90 percent, thanks to broader public outreach, caller ID improvements, and the creation of a system that allows contacts to call back their tracers.

“This thing is like whack a mole, so if you do really well here but not over here then it’s going to pop up over there. I think we’re the only state, as far as I can see, that has done this at scale with these kind of public health metrics,” she said.

“What I have learned from 25 years of epidemic control is you only can do it with a comprehensive approach – prevention, treatment, care,” she said. “If you only do one thing, it’s not going to work.”

Massachusetts public health officials on Monday reported 157 new cases of COVID-19 and 15 deaths. Those numbers are good, but in a number of other states cases are on the rise. Mukherjee said leadership on COVID-19 has varied greatly from state to state and been almost entirely absent at the national level. “This can’t be a state by state thing,” she said.

Mukherjee also said she is not confident a COVID-19 vaccine will be developed soon. “I personally don’t see a vaccine right around the corner,” she said. “I think we’re going to be living with this for a very long time.”