Updated vaccine protects against SARS-CoV-2 variants including Omicron (B.1.1.529) and prevents transmission in hamsters

• Published in: Nature communications Vol. 13; no. 1; pp. 6644 - 11
• Main Authors: Sharma, Sapna, Vercruysse, Thomas, Sanchez-Felipe, Lorena, Kerstens, Winnie, Rasulova, Madina, Bervoets, Lindsey, De Keyzer, Carolien, Abdelnabi, Rana, Foo, Caroline S., Lemmens, Viktor, Van Looveren, Dominique, Maes, Piet, Baele, Guy, Weynand, Birgit, Lemey, Philippe, Neyts, Johan, Thibaut, Hendrik Jan, Dallmeier, Kai
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 04-11-2022; Nature Publishing Group; Nature Portfolio
• Subjects: 13/106; 13/109; 631/250/255/2514; 631/250/590/1867; 631/326/596/4130; 64; Animals; Antibodies; Antibodies, Neutralizing; Antibodies, Viral; Antigens; Coronaviruses; COVID-19 - prevention & control; COVID-19 Vaccines; Cricetinae; Disease transmission; Fever; Hamsters; Humanities and Social Sciences; Humans; Immunization; Immunogenicity; multidisciplinary; Pandemics; SARS-CoV-2 - genetics; Science; Science (multidisciplinary); Severe acute respiratory syndrome coronavirus 2; Spike Glycoprotein, Coronavirus - genetics; Vaccines; Vector-borne diseases; Viral diseases; Viral Vaccines - genetics; Viruses; Yellow Fever Vaccine
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-34439-7

Current COVID-19 vaccines are based on prototypic spike sequences from ancestral 2019 SARS-CoV-2 strains. However, the ongoing pandemic is fueled by variants of concern (VOC) escaping vaccine-mediated protection. Here we demonstrate how immunization in hamsters using prototypic spike expressed from yellow fever 17D (YF17D) as vector blocks ancestral virus (B lineage) and VOC Alpha (B.1.1.7) yet fails to fully protect from Beta (B.1.351). However, the same YF17D vectored vaccine candidate with an evolved antigen induced considerably improved neutralizing antibody responses against VOCs Beta, Gamma (P.1) and the recently predominant Omicron (B.1.1.529), while maintaining immunogenicity against ancestral virus and VOC Delta (B.1.617.2). Thus vaccinated animals resisted challenge by all VOCs, including vigorous high titre exposure to the most difficult to cover Beta, Delta and Omicron variants, eliminating detectable virus and markedly improving lung pathology. Finally, vaccinated hamsters did not transmit Delta variant to non-vaccinated cage mates. Overall, our data illustrate how current first-generation COVID-19 vaccines may need to be updated to maintain efficacy against emerging VOCs and their spread at community level.
Currently licensed COVID-19 vaccines are based on antigen sequences of early SARS-CoV-2 isolates, despite the prevalence of variants of concerns escaping vaccine-mediated protection. Using their updated yellow fever 17D vectored candidate, here, authors assess neutralising antibody responses against variants of concern, and demonstrate protection and reduced transmission in a hamster model.