Author:
Chalkias Spyros,McGhee Nichole,Whatley Jordan L.,Essink Brandon,Brosz Adam,Tomassini Joanne E.,Girard Bethany,Wu Kai,Edwards Darin K.,Nasir Arshan,Lee Diana,Avena Laura E.,Feng Jing,Deng Weiping,Montefiori David C.,Baden Lindsey R.,Miller Jacqueline M.,Das Rituparna
Abstract
AbstractBackgroundSubvariants of the severe acute respiratory syndrome coronavirus (SARS-CoV-2) omicron XBB-lineage have the potential to escape immunity provided by prior infection or vaccination. For Covid-19 immunizations beginning in the Fall 2023, the U.S. FDA has recommended updating to a monovalent omicron XBB.1.5-containing vaccine.MethodsIn this ongoing, phase 2/3 study participants were randomized 1:1 to receive 50-µg doses of mRNA-1273.815 monovalent (50-µg omicron XBB.1.5 spike mRNA) or mRNA-1273.231 bivalent (25-µg omicron XBB.1.5 and 25-µg omicron BA.4/BA.5 spike mRNAs) vaccines, administered as 5th doses, to adults who previously received a primary series and 3rd dose of an original mRNA coronavirus disease 2019 (Covid-19) vaccine, and a 4th dose of a bivalent (omicron BA.4/BA.5 and original SARS-CoV-2) vaccine. Interim safety and immunogenicity data 15 days post-vaccination are presented.ResultsIn April 2023, participants received mRNA-1273.815 (n=50) and mRNA-1273.231 (n=51). The median intervals from the prior dose of BA.4/BA.5-containing bivalent vaccine were 8.2 and 8.3 months for the mRNA-1273.815 and mRNA-1273.231 groups, respectively. Both vaccines increased neutralizing antibody (nAb) geometric mean titers against all variants tested at day 15 post-booster nAb compared to pre-booster levels. Geometric mean fold-rises from pre-booster titers after the monovalent booster were numerically higher against XBB.1.5, XBB.1.16 and SARS-CoV-2 (D614G) than those of the bivalent booster and were comparable against BA.4/BA.5 and BQ1.1 variants for both vaccines. The monovalent vaccine also elicited nAb responses against omicron XBB.2.3.2, EG.5.1, FL.1.5.1 and BA.2.86 that were similar to those against XBB.1.5 in a subset (n=20) of participants. The occurrence of solicited adverse reactions and unsolicited adverse events were overall similar to those previously reported for the original mRNA-1273 50-µg and omicron BA.4/BA.5-containing bivalent mRNA-1273 vaccines.ConclusionIn this interim analysis, XBB.1.5-containing monovalent and bivalent vaccines elicited potent neutralizing responses against variants of the omicron XBB-lineage (XBB.1.5, XBB.1.6, XBB.2.3.2, EG.5.1, and FL.1.5.1) as well as the recently emerged BA.2.86 variant. The safety profile of the XBB.1.5-containing vaccine was consistent with those of prior vaccines. These results overall indicate that the XBB.1.5-containing mRNA-1273.815 vaccine has the potential to provide protection against these emerging variants and support the Covid-19 vaccine update in 2023-2024 to a monovalent XBB.1.5-containing vaccine.
Publisher
Cold Spring Harbor Laboratory