What are the current guidelines for initiating antiretroviral therapy and CD4‑guided opportunistic infection prophylaxis and vaccination in adults living with HIV?

AIDS Guidelines and CD4 Count: When to Start ART and Prophylaxis

Start antiretroviral therapy immediately for all HIV-infected adults regardless of CD4 count—delaying treatment increases mortality by 44–57% and accelerates progression to AIDS, tuberculosis, and opportunistic infections. 1, 2

Timing of ART Initiation

• Initiate ART on the day of HIV diagnosis or within 7 days for all patients, irrespective of CD4 count, viral load, age, or clinical status. This recommendation is supported by the highest-quality evidence from three landmark randomized controlled trials (HPTN 052, Temprano ANRS 12136, and START) involving 8,427 adults across 37 countries. 1, 3, 2

• Do not postpone ART while awaiting routine laboratory results—the only exception is HLA-B*5701 testing when an abacavir-containing regimen is planned. All other baseline tests (HIV-1 RNA, CD4 count, resistance genotype, hepatitis serologies, renal/hepatic function, lipids) should be drawn before ART but must not delay treatment. 1, 3, 4

• Eliminate structural barriers (staffing shortages, insurance delays, drug-stock gaps) that prevent same-day ART initiation at the first clinic visit. 1, 3, 4

Preferred First-Line ART Regimens

The following integrase strand transfer inhibitor (InSTI)-based regimens are recommended, listed in order of preference:

Primary Recommendation

• Bictegravir/tenofovir alafenamide (TAF)/emtricitabine (single tablet, once daily) is the preferred first-line regimen because it offers the highest efficacy, best tolerability, strongest resistance barrier, minimal drug-drug interactions, and does not require HLA-B*5701 testing—enabling same-day start. 1, 3, 4

Equally Effective Alternatives

• Dolutegravir + TAF/emtricitabine provides comparable efficacy with extensive long-term safety data and superior renal and bone safety versus tenofovir disoproxil fumarate (TDF). 1, 3

• Dolutegravir/abacavir/lamivudine may be used only after confirming a negative HLA-B*5701 result and should be avoided in patients with significant cardiovascular risk factors; a tenofovir-based regimen is preferred in such cases. 1, 3

When InSTIs Cannot Be Used

• Darunavir/ritonavir (or cobicistat) + TAF/emtricitabine is the preferred protease-inhibitor-based option for patients with suspected or confirmed InSTI resistance. 1, 3

Regimens to Avoid for Rapid Start

• Do not use NNRTI-based regimens or abacavir-containing regimens for same-day initiation because they require baseline resistance testing and HLA-B*5701 results, which delay therapy. Tenofovir-based InSTI regimens are preferred. 3, 4

CD4-Guided Opportunistic Infection Prophylaxis

Pneumocystis Jirovecii Pneumonia (PCP)

• Start trimethoprim-sulfamethoxazole (double-strength, one tablet three times weekly) for all patients with CD4 < 200 cells/µL and continue until CD4 rises above 200 cells/µL for at least 3 consecutive months. 3, 4

• Alternative PCP prophylaxis: Dapsone 100 mg orally once daily may be used in patients intolerant to trimethoprim-sulfamethoxazole. 4

Toxoplasmosis

• The same trimethoprim-sulfamethoxazole regimen used for PCP also provides effective toxoplasmosis prophylaxis in patients with positive toxoplasma IgG serology when CD4 < 100 cells/µL. 4

Mycobacterium Avium Complex (MAC)

• Primary MAC prophylaxis is no longer recommended when effective ART is started promptly, as early treatment markedly lowers MAC incidence. 3, 4

Cryptococcal Disease

• Cryptococcal prophylaxis is not recommended in high-resource settings with low disease prevalence. 3, 4

ART Timing with Specific Opportunistic Infections

Tuberculosis Co-infection

CD4 Count	TB Type	ART Initiation Timing	Rationale
< 50 cells/µL	Non-meningeal TB	Within 2 weeks of TB therapy start	Reduces mortality in severely immunocompromised patients [1,3,4]
≥ 50 cells/µL	Non-meningeal TB	Within 2–8 weeks of TB therapy start	Balances efficacy with risk of IRIS [1,3,4]
Any	TB meningitis	Delay 2–4 weeks after TB treatment	Minimizes risk of severe IRIS [4]

• ART regimens compatible with rifampin-based TB therapy:

  • Dolutegravir 50 mg twice daily, or
  • Efavirenz 600 mg once daily, or
  • Raltegravir 800 mg twice daily, each combined with two NRTIs. 1, 3, 4

• Bictegravir must not be co-administered with rifampin due to significant drug-drug interactions. 1, 3, 4

Cryptococcal Meningitis

• Delay ART for 4–6 weeks after initiating antifungal therapy to lower the risk of severe immune reconstitution inflammatory syndrome (IRIS). 1, 3, 4

• Start ART at 2 weeks if the patient shows clinical improvement, controlled intracranial pressure, negative CSF cultures, and can be closely monitored. 4

Other Opportunistic Infections

• For most other OIs (e.g., Pneumocystis pneumonia, bacterial infections), initiate ART within 2 weeks of starting infection-specific therapy. 1, 3, 4

Malignancy

• Initiate ART immediately upon cancer diagnosis while carefully managing drug-drug interactions. 1, 3, 4

Special Populations

Pregnancy

• Preferred regimen: Dolutegravir + TAF/emtricitabine. 3, 4

• If a protease inhibitor is required, use darunavir 600 mg + ritonavir 100 mg twice daily (once-daily dosing is insufficient during pregnancy). 1, 3

• Acceptable alternatives: Atazanavir/ritonavir, raltegravir, and efavirenz combined with tenofovir-based dual-NRTI backbones. 1, 3

Renal or Bone Disease

• Avoid TDF in patients with creatinine clearance < 60 mL/min or with osteopenia/osteoporosis; use TAF instead to reduce nephrotoxicity and bone loss. 1, 3, 4

Hepatitis B Co-infection

• Start an ART regimen that includes TDF or TAF together with lamivudine or emtricitabine to provide dual activity against HBV. 1, 4

• Entecavir may be added for HBV treatment but should be avoided if HIV-RNA is not suppressed, as it can select for HIV drug resistance. 1

Post-Initiation Monitoring

Viral Load Monitoring

• Check HIV-1 RNA viral load at 4–6 weeks after starting ART, then every 4–6 weeks until undetectable (< 50 copies/mL), then every 3 months for the first year, then every 6 months once stable suppression is achieved. 3, 5, 4

CD4 Monitoring

• Monitor CD4 count every 6 months until > 250 cells/µL for 1 year with viral suppression, then can be discontinued after CD4 > 500 cells/µL for 2 years with sustained viral suppression. 3, 5, 4

Common Pitfalls to Avoid

• Do not delay ART while awaiting complete laboratory results (except HLA-B*5701 for abacavir)—postponement eliminates the survival benefit of early treatment. 1, 3, 4

• Never prescribe abacavir without confirming a negative HLA-B*5701 result to prevent potentially fatal hypersensitivity reactions. 1, 3

• Do not prescribe TDF to patients with creatinine clearance < 60 mL/min or with osteoporosis—this leads to avoidable nephrotoxicity and bone loss; TAF should be used instead. 1, 3, 4

• In cryptococcal meningitis, do not start ART too early without meeting strict clinical criteria (clinical improvement, controlled intracranial pressure, negative CSF cultures), as this raises the risk of severe IRIS. 1, 3, 4

• In patients with CD4 < 50 cells/µL and TB, delaying ART beyond 2 weeks markedly increases mortality—do not postpone treatment. 1, 3, 4