Dormant proviruses are the single biggest obstacle to curing HIV. When HIV infects a cell, it splices a copy of its genetic code into the cell's own DNA, and some of those infected cells go quiet, sitting silent and untouched by antiretroviral therapy (ART). This hidden "latent reservoir" survives treatment and reseeds the infection if therapy ever stops, so HIV is controllable but not yet curable HHS.
Key figures
- Acute symptoms
- 2–4 wks
- flu-like; many have none
- NAT detects
- 10–33 days
- Antibody test
- 23–90 days
- U=U
- no transmission
- when undetectable
| Item | Value |
|---|---|
| Acute symptoms | 2–4 wks: flu-like; many have none |
| NAT detects | 10–33 days |
| Antibody test | 23–90 days |
| U=U | no transmission: when undetectable |
The essentials: what a provirus is and why it matters
HIV is a retrovirus: it carries its genes as RNA and converts them to DNA inside the cells it infects. That DNA, called the provirus, gets stitched directly into the human cell's chromosome by the viral enzyme integrase. Once integrated, the provirus is, for all practical purposes, part of the cell. Most infected cells churn out new virus and die quickly. But a fraction of long-lived immune cells (chiefly resting memory CD4 T cells) carry the provirus in a silent, non-producing state. They look and act like healthy cells, so neither the immune system nor ART has any target to hit.
This is the heart of the problem. ART is excellent at blocking the steps the virus needs to replicate. The drug classes include integrase inhibitors, NRTIs, NNRTIs, and protease inhibitors, often combined in a single pill CDC. But every one of those drugs acts on an active replication step. A provirus that's just sitting there, transcribing nothing, gives the medicine nothing to do. The reservoir is laid down within days of infection, long before most people are even diagnosed, and it persists for the life of those cells, which can be decades.
So an undetectable viral load is real and powerful, but it controls the virus rather than eradicating it. The virus in the blood drops below what tests can measure because active replication is suppressed; the integrated proviruses remain, hidden in cells and tissues. There's currently no effective cure, and people who acquire HIV have it for life CDC. Stopping ART releases the brake, dormant cells reactivate, and the virus rebounds, usually within weeks.
Sterilizing cure vs. functional cure
Researchers split "cure" into two goals. A sterilizing cure means clearing every replication-competent provirus from the body. A functional cure means the virus persists but stays controlled with no ongoing ART, a remission rather than eradication NIAID. What's available today is neither: lifelong, effective treatment. Keep that distinction in mind when you read cure headlines.
"Symptoms" of the reservoir, and what it doesn't feel like
The latent reservoir itself causes no symptoms. You can't feel a silent provirus, and standard viral-load and CD4 tests can't measure it directly. What people experience are the stages of HIV when the virus is active. In acute infection, within 2 to 4 weeks of exposure, Most people develop flu-like symptoms, fever, chills, rash, night sweats, muscle aches, sore throat, fatigue, swollen lymph nodes, and mouth ulcers, exactly when the viral load peaks above a million copies/mL and onward transmission risk is highest HHS. You can read more about acute HIV infection and why it's so easy to miss.
After the acute phase comes clinical latency, and here "latency" is confusing. Clinical latency means a person feels well, often for years, but the virus is still active and replicating in the body. That's different from the molecular latency of a dormant provirus inside a single resting cell. Untreated, the disease eventually progresses to AIDS, defined by a CD4 count under 200 cells/mm³ or an opportunistic infection (an infection that takes hold only when the immune system is badly weakened).
Early symptoms look exactly like the flu and many people have none, so symptoms can neither confirm nor rule out HIV. Only a test can StatPearls.
Testing: what the reservoir means for what tests can find
Standard HIV tests measure active virus or the antibodies your body makes against it, not the silent reservoir. That's why testing has a window period after exposure. A nucleic-acid test (NAT) can detect virus roughly 10–33 days out; a 4th-generation antigen/antibody lab test, 18–45 days; antibody and rapid tests, 23–90 days. A negative result is conclusive only after the window has passed with no exposure during it CDC.
In practice, testing is quick. A finger-stick or oral-swab rapid test gives results in minutes, and a lab blood test offers the earliest detection. Both are free at many health departments, and at-home kits exist, though you have to mind the window. If you're choosing between options, see the rapid HIV test vs lab test breakdown, the timeline for when to test after exposure, and where to get tested.
The reservoir explains one nuance: people in long-term remission after experimental treatment can still carry detectable proviral DNA or antibodies even when no active virus is found. Detecting and quantifying the reservoir reliably is itself an unsolved research problem, and there's no clinical "reservoir test" you can order.
Treatment: why ART controls but can't clear
All people with HIV should start ART as soon as possible after diagnosis and stay on it for life; the goal is an undetectable viral load, which most people reach within about six months of starting CDC. Started early, before the CD4 count falls below 200, modern treatment gives a 20-year-old a life expectancy approaching that of the general population Lancet HIV. Earlier diagnosis and treatment also lowers community spread, since earlier HIV treatment means reaching viral suppression sooner, and a suppressed virus doesn't transmit.
But ART is treatment-dependent control. The reservoir is why interrupting therapy causes rebound, and why "undetectable" never means "cured." That's the practical reality the cure research is trying to change.
The cure-research strategies aimed at the reservoir
Several experimental approaches target the dormant provirus directly. None is an available cure; each is under study NIAID:
- Shock and kill (latency reversal): Drugs called latency-reversing agents force dormant cells to wake up and express HIV, exposing them so the immune system or ART can eliminate them. The hard part is waking the whole reservoir without harming the patient, and making sure the unmasked cells actually die.
- Block and lock: The opposite idea, locking the provirus into permanent, deep silence so it can never reactivate, effectively a functional cure even though the DNA remains.
- Gene/CCR5 editing: Editing immune cells to remove CCR5, the doorway most HIV strains use to enter cells, aiming to make a person's cells resistant.
- Broadly neutralizing antibodies (bnAbs): Lab-made antibodies that can neutralize many HIV strains and help clear infected cells.
- Therapeutic vaccines: Training the immune system to recognize and suppress HIV on its own without daily medication.
The stem-cell transplant cases
A small number of people have reached long-term remission after stem-cell (bone-marrow) transplants: the Berlin patient, the London patient, and a New York woman who was the third documented case and the first woman NIH, 2022. These transplants were done to treat cancer or leukemia, used rare HIV-resistant CCR5-delta32 donor cells, and are high-risk procedures. They prove that remission is possible, but they aren't a scalable or generally available cure for the millions living with HIV HHS.
Prevention: the tools that work right now
Because there's no cure, prevention carries the weight. The CDC's core tools are condoms, PrEP, PEP, treatment-as-prevention (U=U), and regular testing CDC.
U=U is backed by hard trial data. A person who takes ART as prescribed and stays virally suppressed (under 200 copies/mL) does not transmit HIV to sex partners. Across the PARTNER, Opposites Attract, and PARTNER2 studies, more than 125,000 condomless sex acts among mixed-status couples, there were zero linked transmissions while the partner was suppressed PARTNER. Treatment doubles as prevention aidsmap/NAM.
PrEP is for people without HIV who are exposed through sex or injection drug use; taken as prescribed, it cuts HIV risk from sex by about 99% CDC. PEP is the emergency option after a possible exposure; it must start within 72 hours and is taken daily for 28 days, never a substitute for PrEP or condoms CDC. Newer long-acting prevention is moving fast: in the PURPOSE 1 trial, twice-yearly injectable lenacapavir produced zero infections among women, the strongest HIV-prevention result yet WHO.
| Option | Who it's for | How it works against HIV | Effect on the reservoir |
|---|---|---|---|
| ART (treatment) | People living with HIV | Blocks active replication; reaches undetectable | Does not clear dormant proviruses; control only |
| PrEP | HIV-negative, ongoing risk | Prevents the virus from establishing infection | No reservoir forms if it works |
| PEP | HIV-negative, recent exposure (<72 hrs) | Stops infection from taking hold | Aims to prevent a reservoir before it seeds |
| U=U (treatment-as-prevention) | Suppressed people + partners | No transmission while undetectable | Reservoir persists in the treated person |
When to see a clinician
If you think you were exposed in the last 72 hours, treat it as an emergency. Go to urgent care or an ER and ask about PEP today, not after a wait-and-see test. If you had a risk and now have flu-like symptoms, that combination warrants an urgent test, because acute infection is easy to miss and highly contagious. If you're HIV-negative with ongoing risk, ask a clinician about PrEP. And if you're living with HIV, start ART early and stay on it, that keeps you healthy and protects your partners.
Keep exploring on EasySTD: when to re-test, STD incubation periods and HIV/AIDS testing.