Data on vaccine efficacy and immunogenicity in PLWH remains limited (reviewed in (Mullender et al., 2022)), and while there are some conflicting results, meta-analyses (Tamuzi et al., 2022) and recent studies (Woldemeskel et al., 2022) have shown reduced levels of seroconversion and neutralization after a second dose of viral vector vaccine dose in PLWH, with lower CD4 T cell count/viraemia and older age resulting in a more impaired response and more rapid breakthrough infection (Sun et al., 2022). The gene discussed is CD4; the disease is infection.