Virological characteristics of the SARS-CoV-2 Omicron BA.2 spike

Soon after the emergence and global spread of the SARS-CoV-2 Omicron lineage BA.1, another Omicron lineage, BA.2, began outcompeting BA.1. The results of statistical analysis showed that the effective reproduction number of BA.2 is 1.4-fold higher than that of BA.1. Neutralization experiments revealed that immunity induced by COVID vaccines widely administered to human populations is not effective against BA.2, similar to BA.1, and that the antigenicity of BA.2 is notably different from that of BA.1. Cell culture experiments showed that the BA.2 spike confers higher replication efficacy in human nasal epithelial cells and is more efficient in mediating syncytia formation than the BA.1 spike. Furthermore,…

• JA
  Japan Agency for Medical Research and Development

  Awards: 20fk0108517, 21fk0410033, 20fk0108401, 21fk0108617, 20fk0108146, 20fk0108268, 21fk0410039, 21fk0410034, 20fk0108270, 20fk010847, 20fk0108413, 20fk0108451
• TB
  Tokyo Biochemical Research Foundation
• IF
  Institute for Frontier Life and Medical Sciences, Kyoto University
• MO
  Ministry of Education, Culture, Sports, Science and Technology
• KU
  Kumamoto University
• OU
  Osaka University
• MF
  Mitsubishi Foundation
• UO
  University of Tokyo
• TF
  Tsuchiya Foundation
• JS
  Japan Society for the Promotion of Science

  Awards: 18H02662, 22K16375, 20K15767, 22K07103, 21H02737, 21H02736, 19K06382
• JS
  Japan Science and Technology Agency

  Awards: JPMJSC21U5, JPMJSC20U1
• RI
  Research Institute for Microbial Diseases, Osaka University
• CR
  Core Research for Evolutional Science and Technology

  Award: JPMJCR20H4