Epidemiology of COVID-19 after Emergence of SARS-CoV-2 Gamma Variant, Brazilian Amazon, 2020–2021

Journal article

Rapid development and successful use of vaccines against SARS-CoV-2 might hold the key to curb the ongoing pandemic of COVID-19. Emergence of vaccine-evasive SARS-CoV-2 variants of concern (VOCs) has posed a new challenge to vaccine design and development. One urgent need is to determine what types of variant-specific and bivalent vaccines should be developed. Here, we compared homotypic and heterotypic protection against SARS-CoV-2 infection of hamsters with monovalent and bivalent whole-virion inactivated vaccines derived from representative VOCs. In addition to the ancestral SARS-CoV-2 Wuhan strain, Delta (B.1.617.2; δ) and Theta (P.3; θ) variants were used in vaccine preparation. Additional VOCs including Omicron (B.1.1.529) and Alpha (B.1.1.7) variants were employed in the challenge experiment. Consistent with previous findings, Omicron variant exhibited the highest degree of immune evasion, rendering all different forms of inactivated vaccines substantially less efficacious. Notably, monovalent and bivalent Delta variant-specific inactivated vaccines provided optimal protection against challenge with Delta variant. Yet, some cross-variant protection against Omicron and Alpha variants was seen with all monovalent and bivalent inactivated vaccines tested. Taken together, our findings support the notion that an optimal next-generation inactivated vaccine against SARS-CoV-2 should contain the predominant VOC in circulation. Further investigations are underway to test whether a bivalent vaccine for Delta and Omicron variants can serve this purpose.published_or_final_versio

Authors: Nicolete, VC; Rodrigues, PT; Fernandes, ARJ; Corder, RM; Tonini, J

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Centers for Disease Control and Prevention
• Journal: Emerging Infectious Diseases
• Volume: 28
• Issue: 3
• Pages: 709-712
• Publication date: 2021-12-28
• DOI: 10.3201/eid2803.211993
• EISSN: 1080-6059
• ISSN: 1080-6040
• Language: English
• Keywords: Disease; Coronavirus disease 2019 (COVID-19); Virology; Pathology; Severe acute respiratory syndrome; Outbreak; Betacoronavirus; Medicine; Biology; Amazon rainforest; 2019-20 coronavirus outbreak; Epidemiology; Coronavirus; Infectious disease (medical specialty); Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)