HIV pre-exposure prophylaxis or PrEP, the use of drugs to prevent HIV infection, among men who have sex with men can significantly reduce new infections across an entire population of men, a new study finds.

Based on introduction of the intervention, HIV infections diagnosed in men who have sex with men in the Australian state of New South Wales fell by a quarter -- 25.1% -- in one year in the research, published Wednesday in the journal the Lancet.

Diagnoses fell from from 295 in October 2016, before the study, to 221 just 12 months after the PrEP rollout -- the lowest number since HIV surveillance started in New South Wales in 1985.

"The speed and magnitude of response was remarkable," said Andrew Grulich, lead author of the paper and professor of the HIV epidemiology and prevention program at the Kirby Institute in the University of New South Wales.

Grulich believes that the large decline is because PrEP "is acting in a similar way to a vaccine," meaning herd immunity has led to fewer people becoming infected overall in the state of 7 million.

University College London professor of cellular and molecular virology Ariberto Fassati, who was not involved in the new research, explained that there is a "benefit for the larger community if there is a core of individuals that are taking PrEP." Read more via CNN