Severe Acute Respiratory Syndrome Coronavirus 2 Delta Vaccine Breakthrough Transmissibility in Alachua County, Florida

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant has caused a dramatic resurgence in infections in the United Sates, raising questions regarding potential transmissibility among vaccinated individuals. Between October 2020 and July 2021, we sequenced 4439 SARS-CoV-2 full ge...

Full description

Saved in:
Bibliographic Details
Published in:Clinical infectious diseases 2022-10, Vol.75 (9), p.1618-1627
Main Authors: Rife Magalis, Brittany, Rich, Shannan, Tagliamonte, Massimiliano S, Mavian, Carla, Cash, Melanie N, Riva, Alberto, Marini, Simone, Amador, David Moraga, Zhang, Yanping, Shapiro, Jerne, Horine, Amelia, Starostik, Petr, Pieretti, Maura, Vega, Samantha, Paula Lacombe, Ana, Salinas, Jessica, Stevenson, Mario, Myers, Paul, Glenn Morris, J, Lauzardo, Michael, Prosperi, Mattia, Salemi, Marco
Format: Article
Language:English
Subjects:
COVID-19 - epidemiology
COVID-19 - prevention & control
Florida - epidemiology
Humans
Major
Phylogeny
RNA, Viral - genetics
SARS-CoV-2 - genetics
Vaccination
Viral Vaccines
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant has caused a dramatic resurgence in infections in the United Sates, raising questions regarding potential transmissibility among vaccinated individuals. Between October 2020 and July 2021, we sequenced 4439 SARS-CoV-2 full genomes, 23% of all known infections in Alachua County, Florida, including 109 vaccine breakthrough cases. Univariate and multivariate regression analyses were conducted to evaluate associations between viral RNA burden and patient characteristics. Contact tracing and phylogenetic analysis were used to investigate direct transmissions involving vaccinated individuals. The majority of breakthrough sequences with lineage assignment were classified as Delta variants (74.6%) and occurred, on average, about 3 months (104 ± 57.5 days) after full vaccination, at the same time (June-July 2021) of Delta variant exponential spread within the county. Six Delta variant transmission pairs between fully vaccinated individuals were identified through contact tracing, 3 of which were confirmed by phylogenetic analysis. Delta breakthroughs exhibited broad viral RNA copy number values during acute infection (interquartile range, 1.2-8.64 Log copies/mL), on average 38% lower than matched unvaccinated patients (3.29-10.81 Log copies/mL, P 
ISSN:1058-4838
1537-6591
DOI:10.1093/cid/ciac197