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AuthorQassim, Suelen H.
AuthorHasan, Mohammad R.
AuthorTang, Patrick
AuthorChemaitelly, Hiam
AuthorAyoub, Houssein H.
AuthorYassine, Hadi M.
AuthorAl-Khatib, Hebah A.
AuthorSmatti, Maria K.
AuthorAbdul-Rahim, Hanan F.
AuthorNasrallah, Gheyath K.
AuthorAl-Kuwari, Mohamed Ghaith
AuthorAl-Khal, Abdullatif
AuthorCoyle, Peter
AuthorGillani, Imtiaz
AuthorKaleeckal, Anvar Hassan
AuthorShaik, Riyazuddin Mohammad
AuthorLatif, Ali Nizar
AuthorAl-Kuwari, Einas
AuthorJeremijenko, Andrew
AuthorButt, Adeel A.
AuthorBertollini, Roberto
AuthorAl-Romaihi, Hamad Eid
AuthorAl-Thani, Mohamed H.
AuthorAbu-Raddad, Laith J.
Available date2022-10-30T12:37:19Z
Publication Date2022-09-13
Publication NameFrontiers in Immunology
Identifierhttp://dx.doi.org/10.3389/fimmu.2022.984784
CitationQassim SH, Hasan MR, Tang P, Chemaitelly H, Ayoub HH, Yassine HM, Al-Khatib HA, Smatti MK, Abdul-Rahim HF, Nasrallah GK, Al-Kuwari MG, Al-Khal A, Coyle P, Gillani I, Kaleeckal AH, Shaik RM, Latif AN, Al-Kuwari E, Jeremijenko A, Butt AA, Bertollini R, Al-Romaihi HE, Al-Thani MH and Abu-Raddad LJ (2022) Effects of SARS-CoV-2 Alpha, Beta, and Delta variants, age, vaccination, and prior infection on infectiousness of SARS-CoV-2 infections. Front. Immunol. 13:984784. doi: 10.3389/fimmu.2022.984784
URIhttps://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85138859572&origin=inward
URIhttp://hdl.handle.net/10576/35599
AbstractIn 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.
Languageen
PublisherFrontiers Media
Subjectbreakthrough infection
COVID-19
epidemiology
immunity
PCR
reinfection
SARS-CoV-2 variant
vaccine
TitleEffects of SARS-CoV-2 Alpha, Beta, and Delta variants, age, vaccination, and prior infection on infectiousness of SARS-CoV-2 infections
TypeArticle
Volume Number13
ESSN1664-3224
dc.accessType Open Access


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