Waning of vaccine protection against SARS-CoV-2 infection is currently a concern and durability of specific immunity after vaccination in PLWH is still unknown. The aim of this analysis was to evaluate persistence of immune response to mRNA vaccines in PLWH with advanced disease.
PLWH with a CD4 count ?200/mm3 and/or previous AIDS, enrolled in a SARS-CoV-2 vaccination program at INMI hospital in Rome, Italy, were evaluated >90 days after 2nd dose of BNT162b2 or mRNA-1273 (time T1). Anti-RBD by CLIA, neutralizing antibody (nAb) titers by microneutralization assay (MNA90) and IFN? production were assessed and response defined as having anti-RBD >7.1 BAU/mL, nAbs ?1:10, IFN? >12 pg/mL. Participants were stratified by CD4 count (severe immunodeficiency, SID, ?200/mm3; minor immunodeficiency, MID, 201-500/mm3; no immunodeficiency, NID, >500/mm3). Waning of immune response was evaluated in a subgroup of responders for whom two values post 2nd dose were available. Paired t-test was used to test the overall decline. ANOVA and logistic regression analysis controlling for age, viral load, CD4 nadir and cancer were used for comparisons by CD4 groups.
221 pts were included (SID=47; MID=98; NID=76); 81% male; median age 55 yrs (IQR 49-60); median time from HIV diagnosis 7 yrs (3-15); 74% previous AIDS diagnosis; median CD4 nadir 44/mm3 (16-122). All pts receiving ART, 87% with HIV-RNA<50 cp/mL. After a median of 145 (133-157) days after 2nd dose, a detectable anti-RBD response was still present in 83% of SID, 96% of MID and 98% of NID (P=0.0009); nAbs in 38% of SID, 78% of MID and 88% of NID (P<0.0001); IFN? in 67% of SID, 90% of MID and 92% of NID (P=0.0002). Magnitude of residual immune response at T1 was significantly lower in SID (Figure 1a). By logistic regression, risk of nAbs undetectability was higher in SID (aOR 5.03; 95% CI 1.22-20.81) and in MID (aOR 3.77; 11.4-12.48) vs NID, while no evidence for a difference was found for anti-RBD and IFN?. A significant decline of immune response was observed for all immune parameters [mean log2 (SD): -2.66 (1.08), p<0.001, for anti-RBD; -1.23 (1.26), p<0.001, for nAbs; and -0.51 (2.3), p=0.05, for IFN?], regardless of CD4 groups (Figure 1b/c).
A high proportion of PLWH with advanced disease showed a lack of immune response after a median of 5 months from SARS-CoV-2 mRNA vaccination, suggesting an urgent need for a booster dose. A current CD4 ?200/mm3 was associated with higher risk of vanishing of neutralizing activity.