a, b Left, reconstitution of IHG-I in female sex workers (FSWs) who remained HIV− (a) during 10-year follow-up and (b) for at least 4 years according to the IHG at baseline (base.). Right, behavioral activity score (BAS). c–f %IHGs in (c) Left, 43 FSWs (paired) pre- and post-seroconversion with HIV. Right, SIV− and SIV+ sooty mangabeys (SM) (unpaired); (d) sooty mangabeys by SIV serostatus, sex, and age; (e) SIV– Chinese rhesus macaques by sex and age; and (f) the uninfected counterparts of Collaborative Cross-RIX mice grouped by outcomes after Ebola infection. g Groups based on IHG at baseline and predicted IHG before COVID-19 (top). Adjusted odds ratio (aOR) with 95% confidence interval (CI) for hospitalization (middle), and adjusted hazard ratio (aHR) with 95% CI for all-cause, 30-day mortality (bottom) from two separate models, adjusted by age strata. Model 1, by baseline IHG; and model 2, by CMV serostatus. %IHG-III was low (Fig. 3b) and not included in the models. h Time to second occurrence of cutaneous squamous cell carcinoma (CSCC) by IHG at time of first occurrence of CSCC in renal transplant recipients. i Time to AIDS (CDC 1993 criteria) by baseline IHG with median CD4+ and CD8+ counts, CD4:CD8 ratio and HIV viral load (HIV-VL) values at entry to the early HIV infection cohort (EIC). P, for differences in HIV-VL vs. IHG-I is shown. j HIV-VL by entry IHG in the primary HIV infection cohort (PIC). k HIV-VL at entry and subsequent 5 years of therapy-naïve follow-up in EIC participants. Differences in HIV-VL are between participants with IHG-I vs. rest (i.e., IHG-II, IHG-III, or IHG-IV) at the indicated timepoints. *P < 0.05; **P < 0.01; ***P < 0.001; ns nonsignificant. For box plots: center line, median; box, interquartile range (IQR); whiskers, rest of the data distribution and outliers greater than ±1.5 × IQR are represented as points. Two-sided tests were used. Statistics are outlined in Supplementary Information Section 11.3.4., P values are in Supplementary Data 14, and Source data are provided as a Source Data file.