NEW YORK — Charlie Ferrusi is a 23-year-old gay man with a winning smile and an easygoing manner. In May, he completed a master’s degree in public health and recently began a job at the New York State Department of Health AIDS Institute.

Ferrusi said he is HIV-negative and would like to stay that way. He’s the kind of person that could be taking Truvada, a once-a-day pill that is nearly as effective as condoms in preventing HIV, the virus that causes AIDS. Some doctors and politicians have hailed the antiretroviral drug, known as PrEP, as a key to ending the AIDS epidemic.

“You go into a panic that wouldn’t be there if I was on PrEP,” Ferrusi said. “I’m having a good time and being a good person — and that comes with a risk sometimes. If I can eliminate those risks by taking PrEP, I think it would be a good idea.”

Still, like many others, Ferrusi is grappling with a decision to take the drug as a preventive. When taken as prescribed, PrEP can prevent more than 90 percent of sexually transmitted HIV infections. So why aren’t people jumping on the bandwagon?

The end of ‘condom culture’?

The Food and Drug Administration approved Truvada in 2004 for treating HIV infections. In 2012, it was approved as the first — and still, only — drug for pre-exposure prophylaxis, or PrEP.

It works by establishing a presence of the drug in the cells that HIV targets for infection; the virus can’t produce a genetic code, so it can’t replicate and cause an infection.

Men who have sex with men account for more than half of the 1.2 million people living with HIV in the United States.

“People at high risk who should be offered PrEP include about 1 in 4 sexually active gay and bisexual men, 1 in 5 people who inject drugs and 1 in 200 sexually active heterosexual adults,” according to the Centers for Disease Control and Prevention.

But not everyone is applauding the pill as a major advancement in the fight against HIV and AIDS.

No one, at least publicly, is advocating for using PrEP without condoms. Still, it erodes the “condom culture,” said AIDS Healthcare Foundation President Michael Weinstein, who is among PrEP’s most prominent critics.

“If people take this drug, they’re not going to use condoms. Let’s just be real about it,” Weinstein said.

“The reality is that condoms are 98 percent effective. So if people use condoms, they don’t need to take this pill.”

Weinstein said it might be the best choice for people who refuse to use condoms. But for many people, taking the pill as prescribed could be a challenge. Without insurance, the drug can run about $1,500 per month. Many insurance plans, as well as Medicaid, cover it, and the drug’s maker, Gilead Sciences, offers assistance for people who can’t afford the cost.

“The record of people taking pills for every disease is bad,” Weinstein said. “I know that personally when I’ve had to take an antibiotic for 10 days, I’m sure I’m taking it the way I’m supposed to be, and yet I wind up with a bunch of pills in the bottle at the end.”

Another PrEP opponent is longtime activist Larry Kramer, who has been HIV-positive since the late 1980s and takes antiretroviral drugs as treatment. He declined to talk with CNN for this report, but in a 2014 interview with The New York Times, Kramer said of its side effects, “Anybody who voluntarily takes an antiretroviral every day has got to have rocks in their heads.”

Side effects of Truvada include gastrointestinal issues, fatigue, headaches and mild itching or skin rash. Some Truvada patients have experienced kidney and liver problems.

For that reason, anyone taking the medication to prevent infection must have their blood tested every three months to ensure proper kidney and liver function and to make sure they remain HIV-negative.

If someone manages to contract HIV while on PrEP, he or she must switch to a different treatment regimen, so he or she won’t build up a resistance to the medication.

“There’s something, to me, cowardly about taking Truvada instead of using a condom,” Kramer told the Times. “You’re taking a drug that is poison to you, and it has lessened your energy to fight, to get involved, to do anything.”

Changing the psychology of sex

Others say the effects of PrEP extend beyond preventing HIV. It can “revolutionize the psychology of the HIV epidemic,” said Sarit Golub, a Hunter College professor who has been studying the psychological effects of PrEP for years

Golub said her research indicates 40 percent to 60 percent of gay men report thinking about HIV while they’re having sex all or most of the time. She calls that a “psychological tragedy.” Her PrEP patients report significant decreases in anxiety, depression and stress, she said.

“What PrEP is able to do is separate the act of prevention of HIV from the act of sexual intimacy,” Golub said. “And to me, I think that is one of the tremendous powers of PrEP for individuals and for us as a broader community.”

Dr. Demetre Daskalakis, assistant commissioner of the Bureau of HIV/AIDS Prevention and Control for the New York City Department of Health and Mental Hygiene, said that PrEP has the power to change anxiety levels about sex.

“For men who have sex with men and who are of a certain age, there has never been a time that they’ve had sex without having to be very, very worried about HIV constantly,” said Daskalakis, who played an integral role in the FDA’s approval of Truvada for PrEP.

“You can plan ahead by saying, ‘You know, something is going on in my surroundings that is putting me at risk for HIV, so I’m going to take this really, frankly, brave step in taking a medicine every day to prevent HIV infection.’ So it’s not really in the heat of the moment, or ‘I have to put a condom on right now’ or ‘Where is my condom?’ It just gives you the level of security to acknowledge that risks happen and that some people have risk patterns.”

PrEP, Daskalakis said, is not a “forever intervention.” It might appeal to someone in the months after a breakup with a longtime, monogamous partner, after a move to a new place or after the discovery of an interest in higher-risk sex acts. It isn’t immediate either. It takes seven days to build up the full level of protection of the drug in the immune system, and Daskalakis recommends patients continue taking the prescription for 28 days after the risk has subsided.

For individuals who find themselves in a panic after having unsafe sex or after a condom breaks, Daskalakis recommends PEP — post-exposure prophylaxis.

Whereas PrEP is an antiretroviral administered consistently, PEP is prescribed as soon as possible (within 72 hours) following a sexual encounter, and the medication must be taken for 28 days.

PrEP’s social stigma

Truvada has only been on the market as a preventive drug for a few years, but some liken the debate around it to a better-known drug: birth control, when it first went on the market for contraception in the 1960s.

Birth control protects against unwanted pregnancy but does not protect against sexually transmitted infections, including HIV. While Truvada does protect against HIV, it does not protect against other sexually transmitted infections.

Some PrEP studies have shown spikes in the rates of syphilis, gonorrhea and chlamydia among the drug’s users, while other studies have not.

The AIDS Healthcare Foundation’s Weinstein sometimes refers to PrEP as a “party drug,” one he believes is taken mostly by people who want to have unprotected sex.

Daskalakis disagrees.

“I’m feeling like I live somewhere in the ’60s, talking about contraception and sometimes I can imagine deleting the word ‘HIV’ and saying ‘unwanted pregnancy,’ ” he said. “I think there is a lot of what’s called ‘slut shaming’ in the Truvada story, but it’s the exact analogy of what happened in the ’60s with birth control. I mean, we’ve been living 30 years with the dogma that says the only way to be safe — to prevent HIV infection — is using condoms or abstinence.”

Both Daskalakis and Golub said the majority of the PrEP users they counsel are responsible men who have sex with men. Like Ferrusi, they want an added safety net if they choose to have sex with someone whose status is unknown or who is HIV-positive.

“Our ultimate tagline is that we need to customize people’s prevention for what is appropriate for their lifestyle,” Daskalakis said, whether that means condoms or PrEP.

Last summer, New York Gov. Andrew Cuomo outlined a three-point plan to move the state closer to the end of its AIDS epidemic. The goal: dramatically reduce the number of new HIV infections by 2020 and achieve the first-ever decrease in HIV prevalence in New York since the beginning of the crisis in the ’80s.

The plan calls for identifying people who are positive and undiagnosed, keeping people in care so they remain healthy and prevent further transmission — and facilitating access to PrEP for those at high risk.

Although Ferrusi hasn’t taken the drug yet, that plan — Ending the AIDS Epidemic — is the campaign on which he now works. He doesn’t feel any stigma attached to the drug, he said, and he’ll consider taking it in the future.

“I’d be very surprised in myself if I didn’t go on PrEP within the next year,” he said. “I think everything is there, the research is there. I’ve had friends who use it, and they’ve had good experiences.”