Comparison of bivalent and monovalent SARS-CoV-2 variant vaccines: the phase 2 randomized open-label COVAIL trial

AUTHORS

Branche AR , Rouphael NG , Diemert DJ , Falsey AR , Losada C , Baden LR , Frey SE , Whitaker JA , Little SJ , Anderson EJ , Walter EB , Novak RM , Rupp R , Jackson LA , Babu TM , Kottkamp AC , Luetkemeyer AF , Immergluck LC , Presti RM , Bäcker M , Winokur PL , Mahgoub SM , Goepfert PA , Fusco DN , Malkin E , Bethony JM , Walsh EE , Graciaa DS , Samaha H , Sherman AC , Walsh SR , Abate G , Oikonomopoulou Z , El Sahly HM , Martin TCS , Kamidani S , Smith MJ , Ladner BG , Porterfield L , Dunstan M , Wald A , Davis T , Atmar RL , Mulligan MJ , Lyke KE , Posavad CM , Meagher MA , Stephens DS , Neuzil KM , Abebe K , Hill H , Albert J , Telu K , Mu J , Lewis TC , Giebeig LA , Eaton A , Netzl A , Wilks SH , Türeli S , Makhene M , Crandon S , Montefiori DC , Makowski M , Smith DJ , Nayak SU , Roberts PC , Beigel JH , , . Nature medicine. 2023 8 28; ().

PMID: 37640860 [PubMed].

ABSTRACT

Vaccine protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection wanes over time, requiring updated boosters. In a phase 2, open-label, randomized clinical trial with sequentially enrolled stages at 22 US sites, we assessed safety and immunogenicity of a second boost with monovalent or bivalent variant vaccines from mRNA and protein-based platforms targeting wild-type, Beta, Delta and Omicron BA.1 spike antigens. The primary outcome was pseudovirus neutralization titers at 50% inhibitory dilution (ID titers) with 95% confidence intervals against different SARS-CoV-2 strains. The secondary outcome assessed safety by solicited local and systemic adverse events (AEs), unsolicited AEs, serious AEs and AEs of special interest. Boosting with prototype/wild-type vaccines produced numerically lower ID titers than any variant-containing vaccine against all variants. Conversely, boosting with a variant vaccine excluding prototype was not associated with decreased neutralization against D614G. Omicron BA.1 or Beta monovalent vaccines were nearly equivalent to Omicron BA.1 + prototype or Beta + prototype bivalent vaccines for neutralization of Beta, Omicron BA.1 and Omicron BA.4/5, although they were lower for contemporaneous Omicron subvariants. Safety was similar across arms and stages and comparable to previous reports. Our study shows that updated vaccines targeting Beta or Omicron BA.1 provide broadly crossprotective neutralizing antibody responses against diverse SARS-CoV-2 variants without sacrificing immunity to the ancestral strain. ClinicalTrials.gov registration: NCT05289037 .

Tags: 2023 Alumni Publications