There is currently no cure for HIV at any stage, including the earliest days of infection. But acting quickly after exposure or diagnosis can dramatically change the outcome. If you were exposed to HIV within the last 72 hours, post-exposure prophylaxis (PEP) can potentially prevent infection entirely. If you’ve already tested positive, starting treatment immediately shrinks the virus’s foothold in your body to remarkably low levels and allows your immune system to recover fully.
If You Were Exposed in the Last 72 Hours
Post-exposure prophylaxis, or PEP, is a 28-day course of antiretroviral medication that can stop HIV from establishing itself in your body after a known exposure. The critical factor is time. Animal studies show excellent efficacy when PEP starts within 36 hours of exposure. In primate research, PEP initiated at 12 and 36 hours prevented infection completely, while starting at 48 or 72 hours allowed breakthrough infection in about half of subjects.
Human data supports the same pattern. A study of people who took PEP after sexual exposure found that waiting more than 48 hours to start was a significant predictor of the medication failing. Incomplete adherence to the full 28-day course was another major risk factor. If you believe you were exposed, go to an emergency room or urgent care clinic immediately. Every hour matters, and the medication must be taken consistently for the full course to work.
Why “Cure” Isn’t the Right Word Yet
Researchers distinguish between two types of cure. A sterilizing cure means every trace of replication-capable virus is eliminated from the body. A functional cure means the virus is durably suppressed without medication. Neither is currently available through standard treatment.
Only a handful of people have ever achieved a sterilizing cure. The most famous, Timothy Ray Brown (known as the Berlin Patient), received a bone marrow transplant from a donor with a rare genetic mutation that blocks HIV entry into cells. He had no detectable virus for more than 12 years. This procedure is far too dangerous and complex to be a scalable treatment, but it proved that eliminating HIV from the body is biologically possible.
What Early Treatment Actually Achieves
While treatment can’t cure HIV, starting antiretroviral therapy (ART) during the acute phase of infection, roughly the first 30 days, produces results that are strikingly different from starting later. The virus works by inserting its genetic material into your immune cells, creating a hidden reservoir of infected cells that persists even during treatment. The size of that reservoir determines how entrenched the virus becomes.
A longitudinal study published in The Lancet Microbe tracked people who started ART at different points after infection over four years. Those who began treatment within 30 days saw their reservoir of infected cells shrink with an initial half-life of about 13 weeks for total viral DNA. People who started between 31 and 90 days had a slower decline, with a half-life of about 31 weeks. Those who waited beyond 24 weeks had the slowest decline at roughly 90 weeks.
The long-term differences were even more striking. After the initial rapid decline, the reservoir continued shrinking only in the group that started treatment within 30 days. For people who delayed treatment beyond six months, the reservoir essentially stopped shrinking at all, stabilizing at a higher level indefinitely. This means early treatment doesn’t just buy time. It fundamentally changes how much virus your body carries for years afterward.
Undetectable Means Untransmittable
Once ART suppresses the virus to undetectable levels in your blood, you cannot transmit HIV to sexual partners. This principle, known as U=U (Undetectable equals Untransmittable), is backed by extensive data. A systematic review covering more than 2,383 couples, over 160,000 acts of vaginal or anal intercourse, and 3,578 couple-years of follow-up found zero linked transmissions when the HIV-positive partner was on effective treatment. The estimated transmission risk was 0.000 per 100 couple-years.
Most people reach an undetectable viral load within one to six months of starting ART. Reaching that point faster is another advantage of starting treatment early, before the virus has time to replicate widely and damage your immune system.
Immune Recovery After Early Treatment
HIV attacks CD4 cells, the immune cells that coordinate your body’s defense against infections. Without treatment, CD4 counts drop steadily over years, eventually leaving you vulnerable to opportunistic infections (the stage known as AIDS). Starting ART early, before significant CD4 depletion occurs, allows these cells to bounce back to healthy levels. Research on early-treated individuals shows CD4 levels typically stabilize within 3 to 13 months after starting treatment, and when viral suppression is achieved quickly, the depletion is usually mild enough that CD4 counts can recover fully.
People who start treatment later, after their CD4 counts have dropped substantially, often see improvement but may never reach the same baseline they would have had with earlier intervention. This is one of the strongest practical arguments for testing early and treating immediately.
Getting Tested Early
Standard antibody-based HIV tests can miss an infection in its first few weeks because your body hasn’t produced enough antibodies to detect. A nucleic acid test (NAT), which looks for the virus’s genetic material directly, can detect HIV as early as 10 to 33 days after exposure. If you suspect a very recent exposure, ask specifically for a NAT rather than a standard rapid test. Fourth-generation tests that detect both antibodies and a viral protein called p24 antigen fall somewhere in between, with a window of about 18 to 45 days.
What Treatment Looks Like Today
Current first-line HIV treatment typically involves one or two pills taken daily. The 2024 recommendations from the International Antiviral Society favor regimens built around newer medications that block a specific step in how HIV inserts itself into your DNA. These regimens achieve high rates of viral suppression, have relatively few side effects, interact minimally with other medications, and are highly resistant to the virus developing workarounds.
Treatment is lifelong. Stopping ART allows the virus to rebound from its hidden reservoir, usually within weeks. But for people who stay on treatment, life expectancy now approaches that of people without HIV, particularly for those who start early and maintain viral suppression.
Gene Editing and the Search for a True Cure
The most promising avenue toward an actual cure involves gene-editing technology called CRISPR-Cas9, which can be programmed to cut specific sequences of DNA. Researchers are exploring two strategies: editing the virus’s genetic material out of infected cells, and modifying a person’s immune cells so HIV can no longer enter them (mimicking the natural mutation that protected the Berlin Patient’s bone marrow donor). This technology is still in early clinical investigation, and no gene-editing cure is available outside of research settings. But it represents the most realistic path toward eliminating the virus from the body entirely.