• Homologous and Heterologous Covid-19 Booster Vaccinations.

      Atmar, Robert L; Lyke, Kirsten E; Deming, Meagan E; Jackson, Lisa A; Branche, Angela R; El Sahly, Hana M; Rostad, Christina A; Martin, Judith M; Johnston, Christine; Rupp, Richard E; et al. (Massachusetts Medical Society, 2022-01-26)
      In this phase 1-2, open-label clinical trial conducted at 10 sites in the United States, adults who had completed a Covid-19 vaccine regimen at least 12 weeks earlier and had no reported history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection received a booster injection with one of three vaccines: mRNA-1273 (Moderna) at a dose of 100 μg, Ad26.COV2.S (Johnson & Johnson-Janssen) at a dose of 5×1010 virus particles, or BNT162b2 (Pfizer-BioNTech) at a dose of 30 μg. The primary end points were safety, reactogenicity, and humoral immunogenicity on trial days 15 and 29.
    • Rapid decline in vaccine-boosted neutralizing antibodies against SARS-CoV-2 Omicron variant.

      Lyke, Kirsten E; Atmar, Robert L; Islas, Clara Dominguez; Posavad, Christine M; Szydlo, Daniel; Paul Chourdhury, Rahul; Deming, Meagan E; Eaton, Amanda; Jackson, Lisa A; Branche, Angela R; et al. (Elsevier, 2022-06-20)
      ctive immunity. We assess the magnitude and short-term durability of neutralizing antibodies after homologous and heterologous boosting with mRNA and Ad26.COV2.S vaccines. All prime-boost combinations substantially increase the neutralization titers to Omicron, although the boosted titers decline rapidly within 2 months from the peak response compared with boosted titers against the prototypic D614G variant. Boosted Omicron neutralization titers are substantially higher for homologous mRNA vaccine boosting, and for heterologous mRNA and Ad26.COV2.S vaccine boosting, compared with homologous Ad26.COV2.S boosting. Homologous mRNA vaccine boosting generates nearly equivalent neutralizing activity against Omicron sublineages BA.1, BA.2, and BA.3 but modestly reduced neutralizing activity against BA.2.12.1 and BA.4/BA.5 compared with BA.1. These results have implications for boosting requirements to protect against Omicron and future variants of SARS-CoV-2. This trial was conducted under ClincalTrials.gov: NCT04889209.