By Alaa Elassar and Laura Diaz-Zuniga, CNN

(CNN) -- Starting January 1, 2018, it will no longer be a major crime in California to knowingly expose a sexual partner to HIV without disclosing the infection. Gov. Jerry Brown signed legislation on Friday that lowers the offense from a felony to a misdemeanor.

The California legislature passed SB 239 on September 11.

The law previously punished people who knowingly exposed or infected others with HIV by up to eight years in prison. This new legislation will lower jail time to a maximum of six months.

The new law also reduces the penalty for knowingly donating HIV-infected blood from a felony to a misdemeanor.

Bill sponsors Sen. Scott Wiener and Assemblyman Todd Gloria, both Democrats, argued California law was outdated and stigmatized people living with HIV, especially given recent advancements in medicine. Evidence has shown that a person with HIV who undergoes regular treatment has a negligible chance of spreading the infection to others through sexual contact.

"The most effective way to reduce HIV infections is to destigmatize HIV," Wiener told CNN. "To make people comfortable talking about their infection, get tested, get into treatment."

Since the previous law did not require a risk of infection, meaning people on HIV medication could still be charged with a felony, Wiener told CNN it was "extreme and discriminatory."

Gloria released a statement Friday saying the bill will put the state "at the forefront in the fight to stop the spread of HIV."

Wiener said by destigmatizing HIV, the bill would encourage people to get tested, which will in turn lower HIV transmission in the state.

CNN was not able to immediately reach the governor for comment.

Opposition to the bill

Many Republicans staunchly opposed SB 239, saying it could lead to an increase in HIV infections.

Sen. Jeff Stone voted against the bill and strongly expressed his disapproval in September when the Senate voted on it.

Stone, who is also a pharmacist, took aim at Wiener and Gloria's argument that modern medicine can lower the spread of HIV. The senator said three out of four people who are on prescription medication in the United States do not comply with their doctor's orders on how to take it.

"If you don't take your AIDS medications and you allow for some virus to duplicate and show a presence, then you are able to transmit that disease to an unknowing partner," Stone said on the Senate floor.

Sen. Joel Anderson, another Republican who voted against the bill, argued that people infected with HIV could never live their lives "to the same extent" again. He said it was irresponsible not to disclose the possibility of a life-altering infection.

"The critical word in this is 'intentionally,'" Anderson said in September. "When you intentionally put others at risk, you should have responsibility."

CNN reached out to both senators for comment but did not hear back.

Organizational and LGBT support

The bill enjoyed support from Californians for HIV Criminalization Reform (CHCR), a coalition of several organizations, including the ACLU of California, whose mission is to replace the "stigmatizing laws that criminalize HIV status."

Rick Zbur, executive director of Equality California -- one of the organizations in the coalition -- told CNN his group was "elated" that the governor signed the bill and changed the state's "archaic laws."

"This is an important bill that modernizes California's HIV laws," Zbur told CNN. "It will really advance public health and reduce stigma and discrimination that people living with HIV have suffered."

The Los Angeles LGBT Center also supported the bill. The organization's director of government relations, Aaron Fox, told CNN the new law will see HIV-positive people "treated fairly under California law."

The-CNN-Wire

™ & © 2017 Cable News Network, Inc., a Time Warner Company. All rights reserved.