Comparison of AstraZeneca and sinopharm vaccines as boosters in protection against COVID-19 infection

Biologicals, Год журнала: 2023, Номер 82, С. 101668 - 101668

Опубликована: Март 13, 2023

Язык: Английский

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Infectious SARS-CoV-2 in Exhaled Aerosols and Efficacy of Masks During Early Mild Infection

medRxiv (Cold Spring Harbor Laboratory), Год журнала: 2021, Номер unknown

Опубликована: Авг. 13, 2021

Abstract Background SARS-CoV-2 epidemiology implicates airborne transmission; aerosol infectiousness and impacts of masks variants on shedding are not well understood. Methods We recruited COVID-19 cases to give blood, saliva, mid-turbinate fomite (phone) swabs, 30-minute breath samples while vocalizing into a Gesundheit-II, with without at up two visits days apart. quantified sequenced viral RNA, cultured virus, assayed sera for anti-spike anti-receptor binding domain antibodies. Results enrolled 49 seronegative (mean post onset 3.8 ±2.1), May 2020 through April 2021. detected RNA in 45% fine (≤5 µm), 31% coarse (>5 µm) aerosols, 65% overall all from four alpha-variant cases. Masks reduced by 48% (95% confidence interval [CI], 3 72%) 77% CI, 51 89%) aerosols; cloth surgical were significantly different. The alpha variant was associated 43-fold 6.6 280-fold) increase compared earlier viruses, that remained significant 18-fold 3.4 92-fold) adjusting other potential confounders. Two samples, collected participants wore masks, culture-positive. Conclusion is evolving toward more efficient generation loose-fitting provide but only modest source control. Therefore, until vaccination rates very high, continued layered controls tight-fitting respirators will be necessary. Key Points Cases exhale infectious aerosols evolution favors generation. Loose-fitting moderately reduce aerosol. Ventilation, filtration, UV air sanitation, needed protect vulnerable people public-facing jobs indoor spaces.

Язык: Английский

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Comparison among plaque assay, tissue culture infectious dose (TCID ) and real-time RT-PCR for SARS-CoV-2 variants quantification

Iranian Journal of Microbiology, Год журнала: 2022, Номер unknown

Опубликована: Июнь 20, 2022

Background and Objectives: SARS-CoV-2 variants of concern (VOC) interest (VOI) pose a significant threat to pub- lic health because the rapid change in genome can alter viral phenotypes such as virulence, transmissi- bility ability evade host response. Hence, quantification techniques are essential for timely diagnosis follow-up. Besides, they vital understanding pathogenesis, antiviral evaluation, vaccine de- velopment. Materials Methods: Five isolates SARS-CoV-2: D614G strain (B.1), three VOC (Alpha, Gamma Delta), one VOI (Mu) were used compare quantification, plaque assay, median tissue culture infectiousdose (TCID50) real-time RT-PCR. Results: Plaque assay showed titers between 0.15 ± 0.01×107 1.95 0.09×107 PFU/mL while titer by TCID50 was 0.71 0.01×106 4.94 0.80×106 /mL five isolates. The obtained calculated from assays differed 0.61 log10, 0.59 log10 0.96 Alfa, Gamma, Delta, Mu (p≤0.0007), respectively. No differences observed strain. Real-time PCR exhibited ranging 0.39 0.001×108 3.38 0.04×108 RNA copies/µL all variants. relation copies/mL 1:29800 strain, 1:11700 Alpha, 1:8930 1:12500 1:2950 Mu. Conclusion: comparable but not others Our data demonstrated correlation among E gene copies/µL, units measure commonly quantify load diagnostic research fields. results suggest that proportion infectious virions vitro changes pending on variant, being Mu, variant reaching higher with fewer copies.

Язык: Английский

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A pseudovirus-based platform to measure neutralizing antibodies in Mexico using SARS-CoV-2 as proof-of-concept

Scientific Reports, Год журнала: 2022, Номер 12(1)

Опубликована: Окт. 26, 2022

The gold-standard method to evaluate a functional antiviral immune response is titer neutralizing antibodies (NAbs) against viral pathogen. This historically performed using an in vitro assay of virus-mediated infection, which requires BSL-3 facilities. As these are insufficient Latin American countries, including Mexico, scant information obtained locally about pathogens NAb, assay. An alternative solution with live virus use BSL-2-safe non-replicative pseudovirus. Pseudoviral particles can be engineered display selected pathogen's entry protein on their surface, and deliver reporter gene into target cells upon transduction. Here we comprehensively describe the first development BSL-2 safe NAbs-measuring based production pseudotyped lentiviral particles. proof-of-concept, Nanoluc luciferase-mediated luminescence measurements from transduced SARS-CoV-2 Spike-pseudotyped We applied optimized facility measure NAbs 65 serum samples, evidenced 100% sensitivity, 86.6% specificity 96% accuracy. Overall, this report pseudovirus-based developed Mexico NAbs, cornerstone methodology necessary limited resources settings.

Язык: Английский

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Emerging SARS-CoV-2 Genotypes Show Different Replication Patterns in Human Pulmonary and Intestinal Epithelial Cells

Viruses, Год журнала: 2021, Номер 14(1), С. 23 - 23

Опубликована: Дек. 23, 2021

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) quickly spread worldwide following its emergence in Wuhan, China, and hit pandemic levels. Its tremendous incidence favoured the of viral variants. The current genome diversity SARS-CoV-2 has a clear impact on epidemiology clinical practice, especially regarding transmission rates effectiveness vaccines. In this study, we evaluated replication different isolates representing virus genotypes which have been isolated throughout pandemic. We used three distinct cell lines, including Vero E6 cells originating from monkeys; Caco-2 cells, an intestinal epithelium line humans; Calu-3 pulmonary also humans. RT-qPCR to replicate by quantifying released culture supernatant infected cells. found that similarly but show very replicative capacities This was highlighted for lineages B.1.1.7, B.1.351 P.1, are considered be variants concern. These results underscore importance evaluation characterisation each isolate order establish patterns before performing tests, consideration ideal genotype-cell type pair assay.

Язык: Английский

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