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J Clin Virol ; 162: 105444, 2023 05.
Article in English | MEDLINE | ID: covidwho-2304003


BACKGROUND: SARS-CoV-2 variant surveillance informs vaccine composition and decisions to de-authorize antibody therapies. Though detailed genetic characterization requires whole-genome sequencing, targeted mutation analysis may complement pandemic surveillance efforts. METHODS: This study investigated the qualitative performance of a multiplex oligonucleotide ligation assay targeting 19 spike mutations using 192 whole genome sequenced upper respiratory samples representing SARS-CoV-2 variants of concern. RESULTS: Initial valid results were obtained from 95.8% [95% confidence interval (CI): 92.0 - 98.2; 184/192] of samples. All eight invalid samples were valid on repeat testing. When comparing SARS-CoV-2 oligonucleotide ligase assay SARS-CoV-2 variant calls with whole genome sequencing, overall positive percent agreement was 100% (95% CI: 98.1 - 100.0; 192/192), as was the positive and negative percent agreement for each of the tested variants; Gamma, Delta, Omicron BA.1, BA.2, and BA.4/BA.5. CONCLUSIONS: This multiplexed oligonucleotide ligation assays demonstrated accurate SARS-CoV-2 variant typing compared to whole genome sequencing. Such an approach has the potential to provide improved turnaround compared to sequencing and more detailed mutation coverage than RT-qPCR.

COVID-19 , Humans , COVID-19/diagnosis , SARS-CoV-2/genetics , Biological Assay , Mutation , Oligonucleotides
Cell ; 185(6): 1025-1040.e14, 2022 03 17.
Article in English | MEDLINE | ID: covidwho-1649487


During the SARS-CoV-2 pandemic, novel and traditional vaccine strategies have been deployed globally. We investigated whether antibodies stimulated by mRNA vaccination (BNT162b2), including third-dose boosting, differ from those generated by infection or adenoviral (ChAdOx1-S and Gam-COVID-Vac) or inactivated viral (BBIBP-CorV) vaccines. We analyzed human lymph nodes after infection or mRNA vaccination for correlates of serological differences. Antibody breadth against viral variants is lower after infection compared with all vaccines evaluated but improves over several months. Viral variant infection elicits variant-specific antibodies, but prior mRNA vaccination imprints serological responses toward Wuhan-Hu-1 rather than variant antigens. In contrast to disrupted germinal centers (GCs) in lymph nodes during infection, mRNA vaccination stimulates robust GCs containing vaccine mRNA and spike antigen up to 8 weeks postvaccination in some cases. SARS-CoV-2 antibody specificity, breadth, and maturation are affected by imprinting from exposure history and distinct histological and antigenic contexts in infection compared with vaccination.

Antibodies, Viral , BNT162 Vaccine , COVID-19 , Germinal Center , Antigens, Viral , COVID-19/prevention & control , Humans , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus , Vaccination
Cell Host Microbe ; 29(12): 1738-1743.e4, 2021 12 08.
Article in English | MEDLINE | ID: covidwho-1574127


Different SARS-CoV-2 vaccines are approved in various countries, but few direct comparisons of the antibody responses they stimulate have been reported. We collected plasma specimens in July 2021 from 196 Mongolian participants fully vaccinated with one of four COVID-19 vaccines: Pfizer/BioNTech, AstraZeneca, Sputnik V, and Sinopharm. Functional antibody testing with a panel of nine SARS-CoV-2 viral variant receptor binding domain (RBD) proteins revealed marked differences in vaccine responses, with low antibody levels and RBD-ACE2 blocking activity stimulated by the Sinopharm and Sputnik V vaccines in comparison to the AstraZeneca or Pfizer/BioNTech vaccines. The Alpha variant caused 97% of infections in Mongolia in June and early July 2021. Individuals who recover from SARS-CoV-2 infection after vaccination achieve high antibody titers in most cases. These data suggest that public health interventions such as vaccine boosting, potentially with more potent vaccine types, may be needed to control COVID-19 in Mongolia and worldwide.

Antibodies, Viral/blood , BNT162 Vaccine/administration & dosage , COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , ChAdOx1 nCoV-19/administration & dosage , Mass Vaccination , SARS-CoV-2/drug effects , Adult , Aged , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Antibodies, Viral/biosynthesis , COVID-19/epidemiology , COVID-19/immunology , COVID-19/virology , Female , Gene Expression , Humans , Immune Sera/chemistry , Immunogenicity, Vaccine , Male , Middle Aged , Mongolia/epidemiology , Retrospective Studies , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity