Relative infectiousness of SARS-CoV-2 vaccine breakthrough infections, reinfections, and primary infections.
Nat Commun
; 13(1): 532, 2022 01 27.
Article
in English
| MEDLINE | ID: covidwho-1655582
ABSTRACT
SARS-CoV-2 breakthrough infections in vaccinated individuals and in those who had a prior infection have been observed globally, but the transmission potential of these infections is unknown. The RT-qPCR cycle threshold (Ct) value is inversely correlated with viral load and culturable virus. Here, we investigate differences in RT-qPCR Ct values across Qatar's national cohorts of primary infections, reinfections, BNT162b2 (Pfizer-BioNTech) breakthrough infections, and mRNA-1273 (Moderna) breakthrough infections. Our matched-cohort analyses of the randomly diagnosed infections show higher mean Ct value in all cohorts of breakthrough infections compared to the cohort of primary infections in unvaccinated individuals. The Ct value is 1.3 (95% CI 0.9-1.8) cycles higher for BNT162b2 breakthrough infections, 3.2 (95% CI 1.9-4.5) cycles higher for mRNA-1273 breakthrough infections, and 4.0 (95% CI 3.5-4.5) cycles higher for reinfections in unvaccinated individuals. Since Ct value correlates inversely with SARS-CoV-2 infectiousness, these differences imply that vaccine breakthrough infections and reinfections are less infectious than primary infections in unvaccinated individuals. Public health benefits of vaccination may have been underestimated, as COVID-19 vaccines not only protect against acquisition of infection, but also appear to protect against transmission of infection.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
COVID-19
/
BNT162 Vaccine
/
2019-nCoV Vaccine mRNA-1273
Type of study:
Cohort study
/
Experimental Studies
/
Observational study
/
Prognostic study
/
Randomized controlled trials
Topics:
Vaccines
Limits:
Adolescent
/
Adult
/
Aged
/
Child
/
Female
/
Humans
/
Male
/
Middle aged
/
Young adult
Country/Region as subject:
Asia
Language:
English
Journal:
Nat Commun
Journal subject:
Biology
/
Science
Year:
2022
Document Type:
Article
Affiliation country:
S41467-022-28199-7
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