The memory of the mumps outbreak that spread through Harvard earlier this year may still linger, but summer vacation and a high rate of vaccination have eliminated any active cases on campus.

In total, 66 cases of mumps were confirmed by Harvard University Health Services as of Wednesday, according to Director Paul J. Barreira. Sixty one of those confirmed cases were recorded at the time of Commencement on May 26.

State-wide, there have been 109 confirmed cases and 101 probable cases, according to Larry C. Madoff, the director of epidemiology and immunization for the Massachusetts Department of Public Health.

“There were probably many more cases we don’t even know about, including probably 20 percent with mumps who weren’t symptomatic,” Madoff said. “They may have not even known that they had mumps and spread it.”

Madoff said the decline of mumps could be attributed to the end of the school year, when students left town for the summer.

“The close, dormitory kind of contact that we saw ended, and that really ended the outbreak for the summer,” Madoff said.

Barreira also said state legislation concerning vaccinations helped stall the virus.

“Massachusetts has strict immunization requirements that students must meet in order to register for classes,” Barreira wrote in an email. “Harvard University complies with all state requirements and typically 98 to 99 percent of students are fully vaccinated.”

Talk of mumps swept across the University in late February, after Barreira emailed students informing them of the first two cases. The number of cases rose steadily throughout the spring, and the virus spread to other local universities such as Tufts and Boston University. Infected students were quarantined in the Harvard Inn, a move that drew ire and concern from residents already living there.

“We worked very closely with Harvard UHS and the Cambridge Public Health Department to monitor the cases and make sure that we isolated cases, and instituted measures to try to control contact,” Madoff said. “And that did a lot, I think, to contain the outbreak.”

Madoff said it is difficult to trace the origin of a mumps outbreak.

“Certainly many of the [mumps] cases are vaccine-preventable diseases from other countries and that may have been the case here, but we don’t know for sure,” he said.

Though Harvard administrators initially worried that the outbreak would affect Commencement and other end-of-year events, Barreira said that mumps had no effect on the proceedings.

“Really, the message we want to get out is immunization works, and we’re happy Harvard has such a high rate of people who are vaccinated,” Madoff said.

Although there are currently no active cases at Harvard, Madoff encouraged individuals to seek medical attention and to contact HUHS if symptoms of the virus appear.

“There’s always that possibility, and we need to be vigilant,” he said.

—Staff writer Menaka V. Narayanan can be reached at menaka.narayanan@thecrimson.com. Follow her on Twitter @mnarayanan97.

—Staff writer Kenton K. Shimozaki can be reached at kenton.shimozaki@thecrimson.com. Follow him on Twitter @KentonShimozaki.