Ryan Johnson died Friday after battling the respiratory illness for nearly two months, the NYPD said.
Johnson lived in Brookhaven, N.Y., on Long Island. He suffered from asthma, but had been healthy enough to work on the force for five years. He served at a precinct in Brooklyn.
Suffolk County health officials say Johnson was hospitalized June 17. Anti-viral medication failed to save his life.
Police Commissioner Ray Kelly said Johnson "fought valiantly over many weeks, often expressing his desire to return to the job."