Frontiers in Immunology (Sep 2022)
Effects of SARS-CoV-2 Alpha, Beta, and Delta variants, age, vaccination, and prior infection on infectiousness of SARS-CoV-2 infections
- Suelen H. Qassim,
- Suelen H. Qassim,
- Suelen H. Qassim,
- Mohammad R. Hasan,
- Patrick Tang,
- Hiam Chemaitelly,
- Hiam Chemaitelly,
- Hiam Chemaitelly,
- Houssein H. Ayoub,
- Hadi M. Yassine,
- Hadi M. Yassine,
- Hebah A. Al-Khatib,
- Hebah A. Al-Khatib,
- Maria K. Smatti,
- Maria K. Smatti,
- Hanan F. Abdul-Rahim,
- Gheyath K. Nasrallah,
- Gheyath K. Nasrallah,
- Mohamed Ghaith Al-Kuwari,
- Abdullatif Al-Khal,
- Peter Coyle,
- Peter Coyle,
- Peter Coyle,
- Imtiaz Gillani,
- Anvar Hassan Kaleeckal,
- Riyazuddin Mohammad Shaik,
- Ali Nizar Latif,
- Einas Al-Kuwari,
- Andrew Jeremijenko,
- Adeel A. Butt,
- Adeel A. Butt,
- Adeel A. Butt,
- Roberto Bertollini,
- Hamad Eid Al-Romaihi,
- Mohamed H. Al-Thani,
- Laith J. Abu-Raddad,
- Laith J. Abu-Raddad,
- Laith J. Abu-Raddad,
- Laith J. Abu-Raddad
Affiliations
- Suelen H. Qassim
- Infectious Disease Epidemiology Group, Weill Cornell Medicine-Qatar, Cornell University, Doha, Qatar
- Suelen H. Qassim
- World Health Organization Collaborating Centre for Disease Epidemiology Analytics on HIV/AIDS, Sexually Transmitted Infections, and Viral Hepatitis, Weill Cornell Medicine–Qatar, Cornell University, Qatar Foundation – Education City, Doha, Qatar
- Suelen H. Qassim
- Department of Population Health Sciences, Weill Cornell Medicine, Cornell University, New York, NY, United States
- Mohammad R. Hasan
- Department of Pathology, Sidra Medicine, Doha, Qatar
- Patrick Tang
- Department of Pathology, Sidra Medicine, Doha, Qatar
- Hiam Chemaitelly
- Infectious Disease Epidemiology Group, Weill Cornell Medicine-Qatar, Cornell University, Doha, Qatar
- Hiam Chemaitelly
- World Health Organization Collaborating Centre for Disease Epidemiology Analytics on HIV/AIDS, Sexually Transmitted Infections, and Viral Hepatitis, Weill Cornell Medicine–Qatar, Cornell University, Qatar Foundation – Education City, Doha, Qatar
- Hiam Chemaitelly
- Department of Population Health Sciences, Weill Cornell Medicine, Cornell University, New York, NY, United States
- Houssein H. Ayoub
- Mathematics Program, Department of Mathematics, Statistics, and Physics, College of Arts and Sciences, Qatar University, Doha, Qatar
- Hadi M. Yassine
- Biomedical Research Center, QU Health, Qatar University, Doha, Qatar
- Hadi M. Yassine
- Department of Biomedical Science, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
- Hebah A. Al-Khatib
- Biomedical Research Center, QU Health, Qatar University, Doha, Qatar
- Hebah A. Al-Khatib
- Department of Biomedical Science, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
- Maria K. Smatti
- Biomedical Research Center, QU Health, Qatar University, Doha, Qatar
- Maria K. Smatti
- Department of Biomedical Science, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
- Hanan F. Abdul-Rahim
- Department of Public Health, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
- Gheyath K. Nasrallah
- Biomedical Research Center, QU Health, Qatar University, Doha, Qatar
- Gheyath K. Nasrallah
- Department of Biomedical Science, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
- Mohamed Ghaith Al-Kuwari
- Strategy Planning and Health Intelligence Primary Health Care Corporation, Doha, Qatar
- Abdullatif Al-Khal
- 0Hamad Medical Corporation, Doha, Qatar
- Peter Coyle
- Biomedical Research Center, QU Health, Qatar University, Doha, Qatar
- Peter Coyle
- 0Hamad Medical Corporation, Doha, Qatar
- Peter Coyle
- 1Wellcome-Wolfson Institute for Experimental Medicine, Queens University, Belfast, United Kingdom
- Imtiaz Gillani
- 0Hamad Medical Corporation, Doha, Qatar
- Anvar Hassan Kaleeckal
- 0Hamad Medical Corporation, Doha, Qatar
- Riyazuddin Mohammad Shaik
- 0Hamad Medical Corporation, Doha, Qatar
- Ali Nizar Latif
- 0Hamad Medical Corporation, Doha, Qatar
- Einas Al-Kuwari
- 0Hamad Medical Corporation, Doha, Qatar
- Andrew Jeremijenko
- 0Hamad Medical Corporation, Doha, Qatar
- Adeel A. Butt
- Department of Population Health Sciences, Weill Cornell Medicine, Cornell University, New York, NY, United States
- Adeel A. Butt
- 0Hamad Medical Corporation, Doha, Qatar
- Adeel A. Butt
- 2Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, United States
- Roberto Bertollini
- 3Ministry of Public Health, Doha, Qatar
- Hamad Eid Al-Romaihi
- 3Ministry of Public Health, Doha, Qatar
- Mohamed H. Al-Thani
- 3Ministry of Public Health, Doha, Qatar
- Laith J. Abu-Raddad
- Infectious Disease Epidemiology Group, Weill Cornell Medicine-Qatar, Cornell University, Doha, Qatar
- Laith J. Abu-Raddad
- World Health Organization Collaborating Centre for Disease Epidemiology Analytics on HIV/AIDS, Sexually Transmitted Infections, and Viral Hepatitis, Weill Cornell Medicine–Qatar, Cornell University, Qatar Foundation – Education City, Doha, Qatar
- Laith J. Abu-Raddad
- Department of Population Health Sciences, Weill Cornell Medicine, Cornell University, New York, NY, United States
- Laith J. Abu-Raddad
- Department of Public Health, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
- DOI
- https://doi.org/10.3389/fimmu.2022.984784
- Journal volume & issue
-
Vol. 13
Abstract
In 2021, Qatar experienced considerable incidence of SARS-CoV-2 infection that was dominated sequentially by the Alpha, Beta, and Delta variants. Using the cycle threshold (Ct) value of an RT-qPCR-positive test to proxy the inverse of infectiousness, we investigated infectiousness of SARS-CoV-2 infections by variant, age, sex, vaccination status, prior infection status, and reason for testing in a random sample of 18,355 RT-qPCR-genotyped infections. Regression analyses were conducted to estimate associations with the Ct value of RT-qPCR-positive tests. Compared to Beta infections, Alpha and Delta infections demonstrated 2.56 higher Ct cycles (95% CI: 2.35-2.78), and 4.92 fewer cycles (95% CI: 4.67- 5.16), respectively. The Ct value declined gradually with age and was especially high for children <10 years of age, signifying lower infectiousness in small children. Children <10 years of age had 2.18 higher Ct cycles (95% CI: 1.88-2.48) than those 10-19 years of age. Compared to unvaccinated individuals, the Ct value was higher among individuals who had received one or two vaccine doses, but the Ct value decreased gradually with time since the second-dose vaccination. Ct value was 2.07 cycles higher (95% CI: 1.42-2.72) for those with a prior infection than those without prior infection. The Ct value was lowest among individuals tested because of symptoms and was highest among individuals tested as a travel requirement. Delta was substantially more infectious than Beta. Prior immunity, whether due to vaccination or prior infection, is associated with lower infectiousness of breakthrough infections, but infectiousness increases gradually with time since the second-dose vaccination.
Keywords
