Safety and immunogenicity of a broad-spectrum mosaic vaccine as a booster dose against SARS-CoV-2 Omicron and other circulating variants
Authors: Kaabi Nawal Al , Yang Yun Kai , Liang Yu , Xu Ke , Zhang Xue Feng , Kang Yun , Jin Yu Qin , Hou Jun Wei , Zhang Jing , Yang Tian , Hussein Salah , ElDein Mohamed Saif , Lei Ze Hua , Zhang Hao , Shao Shuai , Liu Zhao Ming , Liu Ning , Zheng Xiang , Su Ji Guo , Yang Sen Sen , Cong Xiangfeng , Tan Yao , Lei Wenwen , Gao Xue Jun , Jiang Zhiwei , Wang Hui , Li Meng , Mekki Hanadi Mekki , Zaher Walid , Mahmoud Sally , Zhang Xue , Qu Chang , Liu Dan Ying , Zhang Jing , Yang Mengjie , Eltantawy Islam , Xiao Peng , Shen Fu Jie , Wu Jin Juan , Han Zi Bo , Du Li Fang , Tang Fang , Chen Shi , Ma Zhi Jing , Zheng Fan , Hou Ya Nan , Li Xin Yu , Li Xin , Wang Zhao Nian , Yin Jin Liang , Mao Xiao Yan , Zhang Jin , Qu Liang , Zhang Yun Tao , Yang Xiao Ming , Wu Guizhen , Li Qi Ming 
Published: September 2022

BACKGROUND

The rising breakthrough infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, especially Omicron and its sub-lineages, have raised an urgent need to develop broad-spectrum vaccines against <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://www.bing.com/ck/a?!&&p=7a72ff758ab318d6JmltdHM9MTY2MTQxMTI5NSZpZ3VpZD03Y2QxMWU0MS1jNGNlLTRjNzAtYjA3Yi0xMTVjZmM1N2RlODQmaW5zaWQ9NTE2Ng&ptn=3&hsh=3&fclid=b014239e-2444-11ed-959d-82aad9d02527&u=a1aHR0cHM6Ly93d3cuY2RjLmdvdi9jb3JvbmF2aXJ1cy8yMDE5LW5jb3YvaW5kZXguaHRtbA&ntb=1">coronavirus disease 2019 (COVID-19). We have developed a mosaic-type recombinant vaccine candidate, named NVSI-06-09, having immune potentials against a broad range of SARS-CoV-2 variants.

METHODS

An ongoing randomized, double-blind, controlled phase 2 trial was conducted to evaluate the safety and immunogenicity of NVSI-06-09 as a booster dose in subjects aged 18 years and older from the United Arab Emirates (UAE), who had completed two or three doses of BBIBP-CorV vaccinations at least 6 months prior to the enrollment. The participants were randomly assigned with 1:1 to receive a booster dose of NVSI-06-09 or BBIBP-CorV. The primary outcomes were immunogenicity and safety against SARS-CoV-2 Omicron variant, and the exploratory outcome was cross-immunogenicity against other circulating strains.

RESULTS

A total of 516 participants received booster vaccination. Interim results showed a similar safety profile between NVSI-06-09 and BBIBP-CorV booster groups, with low incidence of adverse reactions of grade 1 or 2. For immunogenicity, by day 14 after the booster vaccination, the fold rises in neutralizing antibody geometric mean titers (GMTs) from baseline level elicited by NVSI-06-09 were remarkably higher than those by BBIBP-CorV against the prototype strain (19.67 vs 4.47-fold), Omicron BA.1.1 (42.35 vs 3.78-fold), BA.2 (25.09 vs 2.91-fold), BA.4 (22.42 vs 2.69-fold), and BA.5 variants (27.06 vs 4.73-fold). Similarly, the neutralizing GMTs boosted by NVSI-06-09 against Beta and Delta variants were also 6.60-fold and 7.17-fold higher than those boosted by BBIBP-CorV.

CONCLUSIONS

A booster dose of NVSI-06-09 was well-tolerated and elicited broad-spectrum neutralizing responses against SARS-CoV-2 prototype strain and immune-evasive variants, including Omicron and its sub-lineages. The immunogenicity of NVSI-06-09 as a booster vaccine was superior to that of BBIBP-CorV. (Funded by LIBP and BIBP of Sinopharm; ClinicalTrials.gov number, NCT05293548).