Cell Discovery and Journal of Medical Virology: Pengfei Wang's team at Fudan University evaluates in detail the effectiveness of new crown vaccination and breakthrough infected serum against the latest mutant strain of Omicron

The Omicron variant of the new coronavirus, which is now circulating widely around the world, was first detected in Botswana and South Africa in November 2021, and it was quickly replaced The Delta variant became the dominant variant worldwide
.
As the Omicron variant continues to mutate, many new Omicron sublines have been reported to evade vaccine immunity and virus-inducing neutralizing antibodies, which Wang Pengfei's team has previously reported Immune escape from BA.
1, BA.
1.
1, BA.
2, and BA.
3 (Wang X.
et al.
, Emerg Microbes Infect.
2022; Ai J.
et al.
, Cell Host & Microbe.
2022）
。 However, new strains continue to emerge, such as BA.
2.
12.
1, BA.
4 and BA.
5, and more recently BA.
2.
75
.
The complex and high-frequency mutations of the novel coronavirus pose a serious challenge to the effectiveness of current COVID-19 vaccines and antibody therapies, but there is a lack of a comprehensive assessment of the neutralization capacity of vaccine booster vaccination or breakthrough infected serum for all emerging Omicron sublines
。

October 13, 2022, Cell Discovery Wang Pengfei/Zhang Wenhong/Hu Zixin of Fudan University and Xu Chenqi's team from the Center of Excellence in Molecular Cells of the Chinese Academy of Sciences were published online Research paper on Neutralization of Omicron BA.
4/BA.
5 and BA.
2.
75 by booster vaccination or BA.
2 breakthrough infection sera.

The study was constructed based on a GISAID database from January 1, 2022 The main mutant strains that have been circulating to the present day include B.
1.
617.
2, BA.
1, BA.
2, BA.
3 ， BA.
2.
3.
1，BA.
2.
10.
1，BA.
2.
12.
1，BA.
2.
13， BA.
2.
75 and BA.
4/BA.
5, covering more than
91% of all current mutant strains.

The study evaluated booster shots of domestic inactivated vaccine (BBIBP-CorV) or recombinant protein vaccine (ZF2001) and the new coronavirus Omicron BA.
2 Neutralizing sensitivity
of serum to the latest mutant strain of Omicron in breakthrough infected patients.
Although BA.
2.
75 accumulates the largest number of mutations in its spike protein, BA.
4/5 showed the strongest serum escape properties
in both homologous and heterogonal reinforcement groups.
Among the three-dose vaccinated, the heterologous booster group had a higher neutralizing titer for both WT and Delta variants than the homologous booster group
.
Compared with the homologous and heterologous vaccine booster groups, BA.
2 breakthrough infection significantly increased neutralizing antibody titers and was resistant to Omicron BA.
2 and its derived variants and BA.
4/5 Both maintain high neutralizing activity
.

Wang Xun of Fudan University, Ai Jingwen of Huashan Hospital, Li Xiangnan and Zhao Xiaoyu of Fudan University, Wu Jing and Zhang Haocheng of Huashan Hospital and He Xing of the Center of Molecular Cell Excellence of the Chinese Academy of Sciences are the co-first authors of the paper, and Wang Pengfei and Zhang Wenhong are both hired by the School of Life Sciences of Fudan University and the Shanghai Institute of Major Infectious Diseases and Biosafety, and Xu Chenqi of the Center of Molecular Cell Excellence of the Chinese Academy of Sciences and the Key Laboratory of Modern Anthropology of Fudan University of Education and Hu Zixin of the Institute of Artificial Intelligence Innovation and Industry of Fudan University as co-corresponding authors
of the paper.

Previously, on July 22, 2022, Wang Pengfei's team was still in the Journal of Medical Virology A research paper entitled Neutralization of distinct Omicron sublineages by longitudinal vaccination sera was published, longitudinally monitoring different pairs of domestic vaccine immunization sero Effectiveness of
the Omicron variant.
These seras were from individuals who received the BBIBP-CorV or ZF2001 vaccine as a booster dose before and on day 14 after booster dose 28 days, 90 days, 180 days
.
The researchers observed a significant increase in neutralization titer for different Omicron mutant strains after booster vaccination, and the neutralization titer reached its highest point on day 14 or 28 after vaccination, and then showed a continuous downward trend, and the decay rate of different variants was generally similar
.
The neutralization potency of the Omicron variant is significantly lower than that of the wild-type and Delta variants, with BA.
4/5 showing the strongest neutralization escape
.
More importantly, the researchers found that for wild-type, delta variant, and Omicron subspecies, the neutralization titer on day 180 after booster vaccination was significantly higher than that before booster vaccination, further illustrating the importance of
booster vaccination.
Xun Wang, Xiaoyu Zhao, Yuchen Cui, Rui Qiao and Minghui Li of Fudan University are the co-first authors of the paper, and Pengfei Wang, both the School of Life Sciences of Fudan University and the Shanghai Institute of Major Infectious Diseases and Biosafety, are the corresponding authors
of PI.