Safety and Immunogenicity of Recombinant Varicella Zoster Virus Vaccine in People With HIV Who Have a CD4 Count Less Than 300 or Greater Than or Equal to 300 and a Healthy Control Population

Study Description: This phase 1/2 open-label study will evaluate the safety and immunogenicity of the Shingrix recombinant varicella zoster virus vaccine (RZV) in people with HIV (PWH) aged 18 years and older and healthy volunteers aged 50 years and older. Shingrix will be administered by intramuscular (IM) injection during visits at months 0 and 2, and blood will be collected prior to each dose and at follow-up visits at months 3 and 12. Study evaluations will include assessment of adverse events (AEs) by physical examination, safety laboratory evaluations, and participant memory tool, and assessment of response in research immunogenicity assays on blood. Objectives: Primary Objective: -Assess vaccine immunogenicity after administration of a full Shingrix series schedule in PWH based upon CD4 count \< 300 and \>= 300. Secondary Objectives: * Assess vaccine immunogenicity after administration of a full Shingrix series schedule in PWH by age (\< 50 and \>= 50 years). * Compare vaccine immunogenicity in PWH versus healthy volunteers. * Evaluate grade 3 and 4 safety responses in PWH, based upon CD4 count (\< 300 and \>= 300), and healthy volunteers. * Evaluate grade 3 and 4 safety responses in PWH, based upon age (\< 50 and \>= 50), and healthy volunteers. Tertiary/Exploratory Objectives: * Compare immune cell responses in PWH, based upon CD4 count (\< 300 and \>= 300), and healthy volunteers. * Compare immune cell responses in PWH, based upon age (\< 50 and \>= 50 years), and healthy volunteers. * Assess vaccine immunogenicity by varicella zoster serostatus. * Assess zoster reactivation. * Correlate the microbiome profile with vaccine responses. Endpoints: Primary Endpoint: -Fold change of anti-glycoprotein gE (anti-gE) antibody concentrations evaluated regularly through the end of study (months 3 and 12) by CD4 count (\< 300 and \>= 300) run by GlaxoSmithKline (GSK). Secondary Endpoints: * Fold change of anti-gE antibody concentrations evaluated regularly through the end of study (months 3 and 12) by age (\< 50 and \>= 50) run by GSK. * Fold change of anti-gE antibody concentrations evaluated regularly through the end of study (months 3 and 12) in PWH and healthy volunteers run by GSK. * Grade 3 and/or Grade 4 Shingrix AEs (solicited and unsolicited local and systemic). Tertiary/Exploratory Endpoints: * T-cell assays and phenotypes evaluated regularly through end of study. * Varicella zoster serostatus as determined by IgG and IgM antibody levels. * Number of episodes and severity of zoster reactivation (including extradermatomal complications such as neurologic or ophthalmologic complications and adverse sequelae such as post herpetic neuralgia). * Baseline microbiome profile.