A Maine law that imposes strict vaccination requirements survived a referendum on Tuesday, with voters keeping the measure that eliminates religious and philosophical exemptions.

Gov. Janet Mills (D) had strongly urged Mainers not to reject the law, set to take effect September 2021, citing the spread of the coronavirus. After the virus was first identified in China, she noted that “one of the first things that public health officials did was begin to work on a vaccine because vaccines save lives,” The Associated Press reported.

State lawmakers passed the measure last year after a surge in whooping cough cases in the state, which has one of the nation’s highest rates of nonmedical exemptions from vaccination. Medical officials had warned that the vaccination rate for the measles, mumps and rubella vaccine had dropped below 94 percent, the threshold for herd immunity, among kindergarteners.

The law would apply to students and public and private schools and universities, including nursery schools, as well as employees at health care facilities. It earned the support of every major medical organization in the state.

Those in favor of the referendum called the law a giveaway to large pharmaceutical companies. Supporters of the law noted that while vaccines account for billions in sales, they make up only a small fraction of drug company revenues.