A nasal omicron vaccine booster elicits potent neutralizing antibody response against emerging SARS-CoV-2 variants. Issue 1 (31st December 2022)

• Record Type: Journal Article
• Authors: Lam, Joy-Yan; Ng, Yau-Yee; Yuen, Chun-Kit; Wong, Wan-Man; Yuen, Kwok-Yung; Kok, Kin-Hang
• Is Part Of: Emerging microbes & infections. Volume 11:Issue 1(2022)
• Page Start: 964
• Page End: 967
• Publication Date: 2022-12-31
• Subjects: COVID-19 -- SARS-CoV-2 -- nasal protein vaccine booster -- delta variant -- omicron variant; Medical microbiology -- Periodicals; Communicable diseases -- Periodicals; Infection -- Periodicals; 616.9041
• DOI: 10.1080/22221751.2022.2053365
• Languages: English
• ISSNs: 2222-1751

Abstract

ABSTRACT: SARS-CoV-2 has caused the COVID-19 pandemic since early 2020. As of January 2022, the worldwide spreading of SARS-CoV-2 leads to approximately 0.35 billion of human infections and five millions of deaths. Current vaccination is one of the effective ways to control SARS-CoV-2 transmission and reduce the disease severity. However, the antibody level against the immunogen significantly drops several months after the standard two-dose vaccination, and hence a third or fourth dose booster (the same immunogen) has been suggested to boost the antibody response. Here, we described an ultra-effective nasal vaccine booster that potently induced the extraordinary high-level of neutralizing antibody in pre-vaccinated mice. The vaccine booster is composed of a recombinant receptor binding domain of SARS-CoV-2 spike (either wild-type or omicron) fused with a domain of SARS-CoV-2 nucleoprotein. In the absence of adjuvants, a single intranasal administration of the booster in pre-vaccinated mice significantly induced systemic and mucosal antibody responses as evidenced by the elevation of the cross-variant neutralizing antibody and induction of IgA in bronchoalveolar lavage respectively. Most importantly, the single dose nasal vaccine booster (omicron version) potently enhanced the neutralizing activity against authentic SARS-CoV-2 omicron virus infection. Taken together, the induction of respiratory mucosal immunity and the enhancement of cross-variant neutralizing activity by the nasal vaccine booster warrants further clinical trials in humans.