The treatment, known as Post-Exposure Prophylaxis (PEP), is a mixture of various antiretroviral medicines – consisting of tenofovir, lamivudine, atazanavir and ritonavir – that must be taken for up to 28 consecutive days.
According to researchers, early treatment of the deadly virus can reduce its transmission by up to 93 percent.
Recent statistics by the United Nations show that HIV infections worldwide have decreased by 35 percent since 2000 because of preventative measures such as early treatment.
The PEP will be freely-administered to anybody who may have been exposed to HIV, including rape victims or those who have had unprotected sex, according to the Brazilian Health Ministry.
The government also intends to increase its accessibility and provide the treatment in rural areas, so people do not have to make the long journey to the city or visit specialty clinics to obtain it.
Brazilian health officials say the best way to avoid contagion is to seek the PEP treatment within 72 hours of being exposed to it, ideally within the first few hours.
PEP has been available for victims of sexual violence since 1998 and to people who have had unprotected sex since 2011, but no firm rules or guidelines as to its administration have existed until now.
According to the World Health Organization, HIV is the world's leading infectious killer and has been responsible for about 39 million deaths since the first cases were reported in 1981.