['To determine whether concomitant administration of zoster vaccine and polysaccharide pneumococcal-23 vaccine (PPV23) provides sufficient protection against herpes zoster infections.', 'Literature was retrieved through the Centers for Disease Control and Prevention (CDC) website, PubMed (inception-February 2013), and Scopus (inception-February 2013) using the key words herpes zoster, pneumococcal, vaccine, concomitant, simultaneous administration, Pneumovax, Zostavax, and barriers. In addition, reference citations from publications were used.', 'All English-language articles identified from the data sources were evaluated. Two studies evaluating concomitant and nonconcomitant administration of zoster vaccine and PPV23 were included.', 'Current product labeling recommends a 4-week interval between zoster vaccine and PPV23 administration; however, the Food and Drug Administration (FDA) and the CDC promote concomitant administration to prevent a missed opportunity to vaccinate. This has caused confusion among health care professionals regarding the appropriate timing of these vaccines. A randomized trial that evaluated the immunogenicity of zoster vaccine and PPV23 given together versus separated by at least 4 weeks demonstrated that the varicella zoster virus (VZV) antibody levels of concomitant versus nonconcomitant vaccination groups did not meet noninferiority requirements. However, a large retrospective cohort trial that compared the incidence of herpes zoster infections following concomitant versus nonconcomitant administration of PPV23 and zoster vaccine did not find a statistically significant between-group difference.'] Does concomitant administration of pneumococcal-23 and zoster vaccines provide adequate herpes zoster coverage?