Global and regional genetic diversity of HIV-1 in 2010–21: systematic review and analysis of prevalence

Abstract

Background

The extensive global genetic diversity of HIV-1 poses a major challenge to HIV vaccine development. We aimed to determine recent estimates of and changes in the global and regional distributions of HIV-1 genetic variants.

Methods

We conducted a systematic literature review by searching PubMed, Embase, Global Health, and CINAHL for studies containing country-specific HIV-1 subtyping data, published between Jan 1, 2010 and Sep 16, 2022. The proportions of HIV-1 subtypes, circulating recombinant forms (CRFs), and unique recombinant forms (URFs) in each country were weighted by UNAIDS estimates of the numbers of people living with HIV (PLHIV) in each country to obtain regional and global prevalence estimates of HIV-1 subtypes, CRFs, and URFs with 95% CIs for the time periods 2010–15 and 2016–21. The protocol is registered with PROSPERO, CRD42017067164.

Findings

We obtained 1044 datasets, containing HIV-1 subtyping data from 653 013 PLHIV from 122 countries in 2010–2021. In 2016–2021, subtype C accounted for 50·4% (95% CI 50·2–50·7; n=18 570 462 of 36 823 798) of global HIV infections, subtype A for 12·4% (12·2–12·6; n=4 571 250), subtype B for 11·3% (11·1–11·5; n=4 157 686), subtype G for 2·9% (2·9–3·0; n=1 083 568), subtype D for 2·6% (2·5–2·7; n=945 815), subtype F for 0·9% (0·8–0·9; n=316 724), CRFs for 15·1% (14·9–15·3; n=5 564 566), and URFs for 2·0% (1·9–2·1; n=733 374). Subtypes H, J, and K each accounted for 0·1% or less of infections. Compared with 2010–15, we observed significant (p<0·0001) increases in global proportions of subtype A (0·9%, 95% CI 0·7 to 1·1) and subtype C (3·4%, 3·0 to 3·7) and decreases in subtype D (–0·5%, –0·6 to –0·4), subtype G (–0·8%, –1·0 to –0·7), CRFs (–1·0%, –1·3 to –0·8), and URFs (–1·8%, –1·9 to –1·7), with no changes for subtypes B and F. The global proportion of infections attributed to recombinants decreased from 21·6% (95% CI 21·4 to 21·7; n=7 099 252 of 32 622 808) in 2010–15 to 19·3% (19·1 to 19·5; n=7 094 694 of 36 823 798) in 2016–21 (–2·3%, 95% CI –2·6 to –2·0; p<0·0001). Regional distributions of HIV-1 variants were complex and evolving, with global trends in the prevalence of HIV-1 variants supported by trends across the regions.

Interpretation

Global and regional HIV-1 genetic diversity are complex and continue to evolve. Continued and improved surveillance of HIV-1 variants remains vital for HIV vaccine development and implementation.

Funding

None.