Immune Response Against Recent Omicron Sub-Lineages in Persons with HIV Receiving a Protein-Based or mRNA XBB.1.5 SARS-CoV-2 Booster Vaccine

Abstract

The new Nuvaxovid protein-based and Pfizer-BioNTech mRNA-based vaccines targeting Omicron XBB.1.5 were available during the 2023-2024 autumn/winter vaccination campaign for frail individuals, including people with HIV (PWH). We assessed the immune response in 51 PWH on stable ART who received a booster with either the Nuvaxovid protein-based (n = 25) or Pfizer-BioNTech mRNA-based XBB.1.5 vaccine (n = 26). The median age was 57 years (IQR 51-65), the median count of CD4 at T0 was 652/mmc (503-935), and CD4 nadir was 226/mmc (95-340). Samples were collected before (T0) and one month after (T1) the booster. We measured neutralizing antibodies (nAbs) titers against D614G, XBB.1.6, and JN.1 variants and T-cell IFN-γ levels produced upon specific stimulation. Regardless of the vaccine used, we observed a marked increase in nAbs titers from T0 to T1 against all the subvariants, but no evidence for a change in IFN-γ release. After controlling for confounders, there was no evidence for a difference in the T0-T1 change in nAbs titers against XBB.1.16 and JN.1 by the type of vaccine, while Nuvaxovid determined a smaller increase in D614G nAbs (p = 0.008). The XBB.1.5 protein-based vaccine's immunogenicity as a fifth or later booster was comparable to the Pfizer-BioNTech mRNA vaccine, particularly against recent Omicron variants.

Keywords: COVID-19; PWH; SARS-CoV-2 XBB.1.5 vaccine; immunogenicity; neutralizing response.

Figure 1

Neutralizing and T cell response levels in PWH receiving XBB.1.5 vaccines. Geometric means neutralizing antibodies titers (A,B) and median values of IFN-γ (C) at T0 and T1, stratified by intervention. (A,B) p-values of Wilcoxon test and the fold change obtained comparing nAbs at T0 and T1 are indicated above and below the horizontal square bracket, respectively. Dashed lines represent the limit of the detection of the assay, error bars indicate the 95% confidence interval.