TY - JOUR
T1 - Reduction in the infection fatality rate of Omicron variant compared with previous variants in South Africa
AU - Liu, Yuan
AU - Yu, Yangyang
AU - Zhao, Yanji
AU - He, Daihai
N1 - Funding Information:
The work described in this paper was partially supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (HKU C7123-20G).
Publisher Copyright:
© 2022 The Author(s)
PY - 2022/7
Y1 - 2022/7
N2 - Objective: The SARS-CoV-2 Omicron (B.1.1.529) variant has caused global concern. Previous studies have shown that the variant has enhanced immune evasion ability and transmissibility and reduced severity. Methods: In this study, we developed a mathematical model with time-varying transmission rate, vaccination, and immune evasion. We fit the model to reported case and death data up to February 6, 2022 to estimate the transmissibility and infection fatality ratio of the Omicron variant in South Africa. Results: We found that the high relative transmissibility of the Omicron variant was mainly due to its immune evasion ability, whereas its infection fatality rate substantially decreased by approximately 78.7% (95% confidence interval: 66.9%, 85.0%) with respect to previous variants. Conclusion: On the basis of data from South Africa and mathematical modeling, we found that the Omicron variant is highly transmissible but with significantly lower infection fatality rates than those of previous variants of SARS-CoV-2.
AB - Objective: The SARS-CoV-2 Omicron (B.1.1.529) variant has caused global concern. Previous studies have shown that the variant has enhanced immune evasion ability and transmissibility and reduced severity. Methods: In this study, we developed a mathematical model with time-varying transmission rate, vaccination, and immune evasion. We fit the model to reported case and death data up to February 6, 2022 to estimate the transmissibility and infection fatality ratio of the Omicron variant in South Africa. Results: We found that the high relative transmissibility of the Omicron variant was mainly due to its immune evasion ability, whereas its infection fatality rate substantially decreased by approximately 78.7% (95% confidence interval: 66.9%, 85.0%) with respect to previous variants. Conclusion: On the basis of data from South Africa and mathematical modeling, we found that the Omicron variant is highly transmissible but with significantly lower infection fatality rates than those of previous variants of SARS-CoV-2.
KW - COVID-19
KW - Immune evasion
KW - Infection fatality rate
KW - Omicron
UR - http://www.scopus.com/inward/record.url?scp=85129818282&partnerID=8YFLogxK
U2 - 10.1016/j.ijid.2022.04.029
DO - 10.1016/j.ijid.2022.04.029
M3 - Journal article
C2 - 35462038
AN - SCOPUS:85129818282
SN - 1201-9712
VL - 120
SP - 146
EP - 149
JO - International Journal of Infectious Diseases
JF - International Journal of Infectious Diseases
ER -
