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1.
Res Sq ; 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35313592

RESUMO

SARS-CoV-2 infection leads to a broad range of outcomes and immune responses, with the development of neutralizing antibodies generally correlated with protection against reinfection. Here, we have characterized both neutralizing activity and T cell responses in a cluster of subjects with mild disease linked to a single spreading event. Surprisingly, we observed sex-specific associations between spike- and particularly nucleoprotein-specific T cell responses and neutralization, with pro-inflammatory cytokines being linked to higher titers only in males. Using single cell immunoprofiling, which provided matched transcriptome and T-cell receptor (TCR) profiles in restimulated CD4 + and CD8 + cells from these subjects, we identified differences in type I IFN signaling that may underlie this difference in antibody generation. Finally, we also identified several TCRs associated with cytokine producing T cells. Altogether, our work maps the breadth of immunological outcomes of SARS-CoV2 infections and highlight the potential role of sex-specific feedback loops during the generation of neutralizing antibodies.

2.
Cureus ; 14(5): e24652, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35663721

RESUMO

This study was conducted to review relevant articles and demonstrate the prevalence of coronavirus disease 2019 (COVID-19) reinfection among healthcare workers (HCWs). A systemic search was conducted on PubMed and Medline from their inception to July 17, 2021. All statistical analyses were conducted using ReviewManager 5.4.1. Studies meeting the following inclusion criteria were selected: (a) articles having HCWs with COVID-19; (b) studies describing reinfection of COVID-19; and (c) articles having a defined number of patients and controls. Three studies were selected for meta-analysis. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the cohort studies. NOS scores of 1-5 were considered high risk for bias, scores of 6-7 were deemed moderate, and scores >7 were considered low risk for bias. A random-effect model was used when heterogeneity was seen to pool the studies, and the results were reported in inverse variance (IV) and corresponding 95% confidence interval (CI). Pooled prevalence of reinfection of COVID-19 in HCWs was 3% (OR: 0.03 [-0.04, 0.01]; p=0.44; I2 =4%). A non-significant prevalence was found among the healthcare professionals in terms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection in Europe. The preformed antibodies were protective against reinfection. However, the waning of antibodies with respect to time was evident, varying differently in different individuals, thereby resulting in reinfection.

3.
medRxiv ; 2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35665008

RESUMO

Background: Increased reinfection rates with SARS-CoV-2 have recently been reported, with some locations basing reinfection on a second positive PCR test at least 90 days after initial infection. Methods: We identified cases where patients had two positive tests for SARS-CoV-2 and evaluated which of these had been sequenced as part of our surveillance efforts, and evaluated sequencing and clinical data. Results: 750 patients (920 samples) had a positive test at least 90 days after the initial test. The median time between tests was 377 days, and 724 (79%) of the post 90-day positives were collected after the emergence of the Omicron variant in November 2021. Sequencing was attempted on 231 samples and successful in 127. Successful sequencing spiked during the Omicron surge and showed higher median days from initial infection compared to failed sequences (median 398 days compared to 276 days, p<0.0005). A total of 122 (98%) patients showed evidence of reinfection, 45 of which had sequence proven reinfection and 77 had inferred reinfections (later sequence showed a clade that was not circulating when the patient was initially infected). Children accounted for only 4% of reinfections. 43 (96%) of 45 infections with sequence proven reinfection were caused by the Omicron variant, 41 (91%) were symptomatic, 32 (71%), were vaccinated prior to the second infection, and 6 (13%) were Immunosuppressed. Only 2 (4%) were hospitalized, and both had underlying conditions. Conclusion: Sequence proven reinfections increased with the Omicron variant but generally caused mild infections.

4.
Artigo em Inglês | MEDLINE | ID: mdl-35665315

RESUMO

Objective: To examine the clinical characteristics, risk of hospitalization and mortality of patients diagnosed with SARS-CoV-2 reinfection. Patients and Methods: We retrospectively reviewed all patients with SARS-CoV-2 reinfection all Mayo Clinic sites between May 23, 2020, and June 30, 2021 (the period before emergence of delta variant in United States). The reinfection was defined as positive SARS-CoV-2 test ≥ 90 days after initial infection or 45-89 days after with symptomatic second episode. Vaccination status was classified as fully vaccinated, first dose and unvaccinated. Comparative analysis of baseline characteristics and comorbidities was performed by hospitalization and vaccination status. The survival analysis of hospitalized patients was performed using cox-proportional hazard regression. Results: Among 554 reinfected patients, 59 (10.6%) were pediatric, and 495 (89.4%) were adults. The median age was 13.9 years (interquartile range [IQR], 8.5-16.5) for pediatric and 50.2 years (IQR, 28.4-65.6) for adult population. Among adult patients, majority were unvaccinated (83.4%, n=413) and duration to reinfection from initial infection was longest in fully vaccinated group (p < .001). 42 (75%) out of 56 patients were seropositive within seven days of reinfection. In hospitalized adult patients, Charlson Comorbidity Index (CCI) was an independent risk factor for mortality (adjusted hazard ratio [aHR], 0.35; 95% CI, 0.19 to 0.51). Conclusion: In this study, majority of adult patients with SARS-CoV-2 reinfection were unvaccinated. Furthermore, the duration to reinfection was longest in fully vaccinated individuals. Seropositivity was common among adult patients.

5.
Clin Infect Dis ; 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35687580

RESUMO

BACKGROUND: Single-dose vaccination was widely recommended in the pre-Omicron era for persons with previous SARS-CoV-2 infection. The effectiveness of a second vaccine dose in this group in the Omicron era is unknown. METHODS: We linked nationwide population registries in Spain to identify community-dwelling individuals aged 18-64, with a positive SARS-CoV-2 test before single-dose mRNA vaccination (mRNA-1273 or BNT162b2). Every day between January 3 and February 6, 2022 we matched 1:1 individuals receiving a second mRNA vaccine-dose and controls on sex, age, province, first dose type and time, month of primary infection and number of previous tests. We then estimated Kaplan-Meier risks of confirmed SARS-CoV-2 reinfection. We performed a similar analysis in a Delta-dominant period, between July 19 and November 30, 2021. RESULTS: In the Omicron period, estimated effectiveness (95% confidence interval) of a second dose was 62.2% (58.2, 66.4) 7 to 34 days after administration, similar across groups defined by age, sex, type of first vaccine and time since the first dose. Estimated effectiveness was 65.4% (61.1, 69.9) for mRNA-1273 and 52.0% (41.8, 63.1) for BNT162b2. Estimated effectiveness was 78.5% (67.4, 89.9), 66.1% (54.9, 77.5), and 60.2% (55.5, 64.8) when primary infection had occurred in the Delta, Alpha, and pre-Alpha periods, respectively. In the Delta period, the estimated effectiveness of a second dose was 8.8% (-55.3, 81.1). CONCLUSIONS: Our results suggest that, over a month after administration, a second dose of mRNA vaccine increases protection against SARS-CoV-2 reinfection with the Omicron variant among individuals with single-dose vaccination and previously infected with another variant.

6.
Infection ; 2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35696057

RESUMO

OBJECTIVES: To assess the severity of symptoms, duration of infection and viral loads of health-care workers (HCWs) who tested positive for Coronavirus disease 2019 (COVID-19) during Omicron's prevalence, in regard to vaccination and previous infection. METHODS: During 2 weeks of highest rate of COVID-19 cases in Bosnia and Herzegovina, the positive nasopharyngeal swabs were analysed in 141 HCWs by reverse transcription quantitative PCR, targeting four different genes: RdRp, E, N and nsp14. Uniformed questionnaire was used to collect relevant sociodemographic and epidemiological data from HCWs divided into four groups: unvaccinated/not previously infected (group 1); unvaccinated/previously infected (group 2); vaccinated/not previously infected (group 3); and vaccinated/previously infected (group 4). RESULTS: We observed that occurrence of fever and smell or taste loss were more frequent in group 1 (86.4% and 25%) and group 3 (76.9% and 19.2%), in comparison to group 2 (64.4% and 6.7%) and group 4 (69.2% and 3.8%), (p = 0.023 and p = 0.003). Although statistically not significant, group 2 (61.9%), group 3 (65.4%), and group 4 (70.8%) experienced negativization within 7 days of positive RT-qPCR test, whereas 51.2% of HCWs from group 1 tested negative later on. There is no significant difference between all four groups regarding Ct values of analysed genes. CONCLUSION: During Omicron's prevalence, the vaccination had less substantial effect on symptomatic disease among HCWs, while fever and loss of smell or taste were considerably less likely to occur upon reinfection. Since viral loads and negativization periods do not seem to significantly vary, irrespective of pre-existing immunity, systemic vaccination and mask-wearing should still be considered among HCWs.

7.
Int J Mol Sci ; 23(11)2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35682933

RESUMO

Being in the epicenter of the COVID-19 pandemic, our lab tested 193,054 specimens for SARS-CoV-2 RNA by diagnostic multiplex reverse transcription polymerase chain reaction (mRT-PCR) starting in March 2020, of which 17,196 specimens resulted positive. To investigate the dynamics of virus molecular evolution and epidemiology, whole genome amplification (WGA) and Next Generation Sequencing (NGS) were performed on 9516 isolates. 7586 isolates with a high quality were further analyzed for the mutation frequency and spectrum. Lastly, we evaluated the utility of the mRT-PCR detection pattern among 26 reinfected patients with repeat positive testing three months after testing negative from the initial infection. Our results show a continuation of the genetic divergence in viral genomes. Furthermore, our results indicate that independent mutations in the primer and probe regions of the nucleocapsid gene amplicon and envelope gene amplicon accumulate over time. Some of these mutations correlate with the changes of detection pattern of viral targets of mRT-PCR. Our data highlight the significance of a continuous genetic divergence on a gene amplification-based assay, the value of the mRT-PCR detection pattern for complementing the clinical diagnosis of reinfection, and the potential for WGA and NGS to identify mutation hotspots throughout the entire viral genome to optimize the design of the PCR-based gene amplification assay.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , COVID-19/genética , Teste para COVID-19 , Técnicas de Laboratório Clínico/métodos , Humanos , Reação em Cadeia da Polimerase Multiplex , Pandemias , RNA Viral/análise , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2/genética , Sensibilidade e Especificidade
8.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-496220

RESUMO

Omicron (B.1.1.529) is the most recent SARS-CoV-2 variant of concern (VOC), which emerged in late 2021 and rapidly achieved global predominance in early 2022. In this study, we compared the infection dynamics, tissue tropism and pathogenesis and pathogenicity of SARS-CoV-2 D614G (B.1), Delta (B.1.617.2) and Omicron BA.1.1 sublineage (B.1.1.529) variants in a highly susceptible feline model of infection. While D614G- and Delta-inoculated cats became lethargic, and showed increased body temperatures between days 1 and 3 post-infection (pi), Omicron-inoculated cats remained subclinical and, similar to control animals, gained weight throughout the 14-day experimental period. Intranasal inoculation of cats with D614G- and the Delta variants resulted in high infectious virus shedding in nasal secretions (up to 6.3 log10 TCID50.ml-1), whereas strikingly lower level of viruses shedding (<3.1 log10 TCID50.ml-1) was observed in Omicron-inoculated animals. In addition, tissue distribution of the Omicron variant was markedly reduced in comparison to the D614G and Delta variants, as evidenced by in situ viral RNA detection, in situ immunofluorescence, and quantification of viral loads in tissues on days 3, 5, and 14 pi. Nasal turbinate, trachea, and lung were the main - but not the only - sites of replication for all three viral variants. However, only scarce virus staining and lower viral titers suggest lower levels of viral replication in tissues from Omicron-infected animals. Notably, while D614G- and Delta-inoculated cats had severe pneumonia, histologic examination of the lungs from Omicron-infected cats revealed mild to modest inflammation. Together, these results demonstrate that the Omicron variant BA.1.1 is less pathogenic than D614G and Delta variants in a highly susceptible feline model. Author SummaryThe SARS-CoV-2 Omicron (B.1.1.529) variant of concern (VOC) emerged in South Africa late in 2021 and rapidly spread across the world causing a significant increase in the number of infections. Importantly, this variant was also associated with an increased risk of reinfections. However, the number of hospitalizations and deaths due to COVID-19 did not follow the same trends. These early observations, suggested effective protection conferred by immunizations and/or overall lower virulence of the highly mutated variant virus. In this study we present novel evidence demonstrating that the Omicron BA.1.1 variant of concern (VOC) presents a lower pathogenicity when compared to D614G- or Delta variants in cats. Clinical, virological and pathological evaluations revealed lower disease severity, viral replication and lung pathology in Omicron-infected cats when compared to D614G and Delta variant inoculated animals, confirming that Omicron BA.1.1 is less pathogenic in a highly susceptible feline model of infection.

9.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22276316

RESUMO

One of the key features of any infectious disease is whether infection generates long-lasting immunity or whether repeated reinfection is common. In the former, the long-term dynamics are driven by the birth of susceptible individuals while in the latter the dynamics are governed by the speed of waning immunity. Between these two extremes a range of scenarios is possible. During the early waves of SARS-CoV-2, the underlying paradigm was for long-lasting immunity, but more recent data and in particular the 2022 Omicron waves have shown that reinfection can be relatively common. Here we investigate reported SARS-CoV-2 cases in England, partitioning the data into four main waves, and consider the temporal distribution of first and second reports of infection. We show that a simple low-dimensional statistical model of random (but scaled) reinfection captures much of the observed dynamics, with the value of this scaling, k, providing information of underlying epidemiological patterns. We conclude that there is considerable heterogeneity in risk of reporting reinfection by wave, age-group and location. The high levels of reinfection in the Omicron wave (we estimate that 18% of all Omicron cases had been previously infected, although not necessarily previously reported infection) point to reinfection events dominating future COVID-19 dynamics.

10.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22276070

RESUMO

OBJECTIVETo determine if occupation is a risk factor for probable reinfection, hospitalization, and death from COVID-19 in Peruvian healthcare workers infected with SARS-CoV-2. MATERIAL AND METHODSRetrospective cohort study. Healthcare workers who presented SARS-CoV-2 infection between March 1, 2020 and August 9, 2021 were included. Occupational cohorts were reconstructed from the following sources of information: the National Epidemiological Surveillance System, molecular tests (NETLAB), results of serology and antigen tests (SICOVID-19), National Registry of Health Personnel (INFORHUS) and National Information System of Deaths (SINADEF). The incidence of probable reinfection, hospitalization, and death from COVID-19 was obtained in the cohorts of health auxiliaries and technicians, nursing staff, obstetricians, physicians, and other healthcare workers. We evaluated whether occupation was a risk factor for probable reinfection, hospitalization, and death from COVID-19 using a log-binomial generalized linear model, obtaining the adjusted relative risk (RR AJ). RESULTS90,672 healthcare workers were included. 8.1% required hospitalization, 1.7% died from COVID-19, and 2.0% had probable reinfection. A similar incidence of probable reinfection was found in the 5 cohorts (1.9%-2.2%). Physicians had a higher incidence of hospitalization (13.2%) and death (2.6%); however, they were also those who presented greater susceptibility linked to non-occupational variables such as age and comorbidities. The multivariate analysis found that physicians (RR=1.691; CI 95: 1.556-1.837) had a higher risk of hospitalization and that the occupation of health technician and assistant was the only one that constituted a risk factor for mortality from COVID-19 (RR =1.240; 95% CI: 1.052-1.463). CONCLUSIONSPeruvian health technicians and auxiliaries have a higher risk of death from COVID-19 linked to their occupation, while doctors have higher mortality due to non-occupational factors. Physicians had a higher risk of hospitalization independent of the presence of comorbidities and age; likewise, all occupations had a similar risk of probable reinfection.

11.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22275865

RESUMO

Both infection and vaccination, alone or in combination, generate antibody and T cell responses against SARS-CoV-2. However, the maintenance of such responses - and hence protection from disease - requires careful characterisation. In a large prospective study of UK healthcare workers (Protective immunity from T cells in Healthcare workers (PITCH), within the larger SARS-CoV-2 immunity & reinfection evaluation (SIREN) study) we previously observed that prior infection impacted strongly on subsequent cellular and humoral immunity induced after long and short dosing intervals of BNT162b2 (Pfizer/BioNTech) vaccination. Here, we report longer follow up of 684 HCWs in this cohort over 6-9 months following two doses of BNT162b2 or AZD1222 (Oxford/AstraZeneca) vaccination and following a subsequent BNT162b2 booster vaccination. We make three observations: Firstly, the dynamics of humoral and cellular responses differ; binding and neutralising antibodies declined whereas T and memory B cell responses were maintained after the second vaccine dose. Secondly, vaccine boosting restored IgG levels, broadened neutralising activity against variants of concern including omicron BA.1, and further boosted T cell responses. Thirdly, prior infection maintained its impact driving larger as well as broader T cell responses compared to never-infected people - a feature maintained even after the third dose. In conclusion, broadly cross-reactive T cell responses are well maintained over time - especially in those with "hybrid" vaccine and infection-induced immunity - and may contribute to continued protection against severe disease.

12.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22274501

RESUMO

The healthcare workers are considered as a high-risk group for infection with SARS-CoV-2, so they were included in the first stage of the National Plan for Vaccination against COVID-19 in Colombia. An ongoing prospective cohort study to evaluate immune response to vaccination included 490 workers from health institutions in Bogota, Colombia, vaccinated between March and June 2021 with BNT162b2 (Pfizer-BioNtech). Multiple samples were collected during a follow-up period of 6 months after immunization. We report cases of asymptomatic and symptomatic SARS-CoV-2 infections detected in this cohort. For each participant demographic data, vaccination dates, results for SARS-CoV-2 RT-PCR, and detection of antibody (IgG) tests during the follow-up period were collected. SARS-CoV-2 infection was detected in 38 (7.7 %) volunteers. Of these, 81.6% had a positive RT-PCR for SARS-CoV-2, and 18.4% were confirmed by detection of IgG anti-SARS-CoV-2 nucleoprotein; 76.3% of infections occurred after 7 days of second dose. A total of 57.9% of the cases were asymptomatic. No hospitalizations or deaths were registered. When infection occurred, 81.6% of infected participants had presence of IgG anti-S antibodies. In 12 samples in which genomic characterization was achieved, 83.4% corresponded to the variant Mu, 8.3% Gamma, and 8.3% Delta. All findings agree with other reports in different studies that show the benefit of COVID-19 vaccines, protecting specially against severe disease but not against infection or re-infection.

13.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22275858

RESUMO

IntroductionIndividuals with a prior severe acute respiratory corona virus 2 (SARS-CoV-2) infection have a moderate to high degree of protection against reinfection, though seemingly less so when the Omicron variant of SARS-CoV-2 started to circulate. The aim of this study was to evaluate the vaccine effectiveness (VE) against SARS-CoV-2 reinfection, that is, in individuals with prior SARS-CoV-2 infection, during periods with different dominant SARS-CoV-2 variants. MethodsA nationwide cohort study design including all individuals with a confirmed SARS-CoV-2 infection, who were alive and residing in Denmark between 1 January 2020 and 31 January 2022 were used. Using Danish nationwide registries, we obtained information on SARS-CoV-2 infections, Coronavirus Disease 2019 (COVID-19) vaccination, age, sex, comorbidity, staying at hospital and region of affiliation. The study population included were individuals with prior SARS-CoV-2 infection. Crude and adjusted estimates of VE against SARS-CoV-2 reinfection with 95% confidence intervals (CIs) were calculated using Poisson and Cox regression models, respectively. The VE estimates were calculated separately for three periods with different dominant SARS-CoV-2 variants (Alpha (B.1.1.7), Delta (B.1.617.2), or Omicron (B.1.1.529)) and by time since vaccination using unvaccinated as the reference. FindingsThe study population comprised of 209,814 individuals infected before or during the Alpha period, 292,978 before or during the Delta period and 245,530 before or during the Omicron period. Of these, 40,281 individuals had completed their primary vaccination series during the Alpha period (19.2%), 190,026 during the Delta period (64.9%) and 158,563 during the Omicron period (64.6%). VE against reinfection following any COVID-19 vaccine type administered in Denmark, peaked at 85% (95% CI: 37% to 97%) at 104 days or more after vaccination during the Alpha period, 88% (95% CI: 81% to 92%) 14-43 days after vaccination during the Delta period and 60% (95% CI: 58% to 62%) 14-43 days after vaccination during the Omicron period. Waning immunity was observed, and was most pronounced during the Omicron period. InterpretationThis study shows that, in previously infected individuals, completing a primary vaccination series was associated with a significant protection against SARS-CoV-2 reinfection compared with no vaccination for all three variant periods. Even though vaccination seems to protect to a lesser degree against reinfection with the Omicron variant, these findings are of public health relevance as they show that previously infected individuals still benefit from COVID-19 vaccination in all three variant periods.

14.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22276321

RESUMO

IntroductionSince the start of the pandemic SARS-CoV-2 infection has most commonly been confirmed using reverse transcriptase polymerase chain reaction (RT-PCR), with results translated into a binary positive/negative outcomes. Previous studies have found that there is additional useful information in the level of the Cycle threshold (Ct value) of positive cases. Here we characterise variation in Ct values as a proxy for viral loads in more than 3 million test-positive COVID-19 cases in England with the aim of better quantifying the utility of such data. MethodsWe used individual N gene Ct values from symptomatic PCR positive (with Ct value less than 30) Pillar 2 cases in England who self-reported the date of symptom onset, and for whom age, reinfection status, variant status, and the number of vaccines received was available. Those with a positive test result more than 6 days after their reported symptom onset were excluded to mitigate the potential impact of recall bias. We used a generalised additive model, to estimate Ct values empirical mean Ct values for each strata of interest independently as well as to predict Ct values using a model that adjusted for a range of demographic and epidemiological covariates jointly. We present empirical Ct values and compare them to predicted mean Ct values. ResultsWe found that mean Ct values varied by vaccine status, and reinfection status with the number of vaccine doses having little apparent effect. Modelling Ct values as a smooth function of time since onset and other variables struggled to reproduce the individual variation in the data but did match the population-level variation over time relatively well with this being apparently dominated by large differences between variants. Other variation over time was also captured to some degree though their remained several periods where the model could not capture the empirical means with a potential explanation being epidemic phase bias. ConclusionsAnalysing a large dataset of routine Ct values from symptomatic COVID-19 cases in England we found variation based on time since symptom onset, vaccine status, age, and variant. Ct values were highest 1-3 days after symptom onset and differed most due to variant status. We found no clear correlation between previously estimated differences in intrinsic transmissibility and Ct values indicating that this is potentially mediated at least partly by factors other than viral load as estimated using Ct values. We found evidence that a model adjusting for a range of covariates could explain some of the population-level variation over time but systematically underestimated Ct values when incidence was increasing, and overestimated them when incidence was decreasing. This indicates the utility of Ct values from this data source as a tool for surveillance, potentially avoiding some of the biases of aggregated positive counts.

15.
BMJ Open ; 12(6): e058074, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35649594

RESUMO

OBJECTIVE: To identify factors associated with COVID-19 positivity among staff and their family members of icddr,b, a health research institute located in Bangladesh. SETTING: Dhaka, Bangladesh. PARTICIPANTS: A total of 4295 symptomatic people were tested for SARS-CoV-2 by reverse-transcription PCR between 19 March 2020 and 15 April 2021. Multivariable logistic regression was done to identify the factors associated with COVID-19 positivity by contrasting test positives with test negatives. RESULT: Forty-three per cent of the participants were tested positive for SARS-CoV-2. The median age was high in positive cases (37 years vs 34 years). Among the positive cases, 97% were recovered, 2.1% had reinfections, 24 died and 41 were active cases as of 15 April 2021. Multivariable regression analysis showed that age more than 60 years (adjusted OR (aOR)=2.1, 95% CI 1.3 to 3.3; p<0.05), blood group AB (aOR=1.5, 95% CI 1.1 to 2; p<0.05), fever (aOR=3.1, 95% CI 2.6 to 3.7; p<0.05), cough (aOR=1.3, 95% CI 1.1 to 1.6; p<0.05) and anosmia (aOR=2.7, 95% CI 1.3 to 5.7; p<0.05) were significantly associated with higher odds of being COVID-19 positive when compared with participants who were tested negative. CONCLUSIONS: The study findings suggest that older age, fever, cough and anosmia were associated with COVID-19 among the study participants.


Assuntos
COVID-19 , Adulto , Anosmia , Bangladesh/epidemiologia , COVID-19/epidemiologia , Estudos de Casos e Controles , Tosse , Família , Pesquisa sobre Serviços de Saúde , Humanos , Pessoa de Meia-Idade , SARS-CoV-2
16.
Cell Rep Med ; : 100651, 2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35654046

RESUMO

Coronavirus disease 2019 (COVID-19) convalescents living in regions with low vaccination rates rely on post-infection immunity for protection against re-infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluate humoral and T cell immunity against five variants of concern (VOCs) in mild-COVID-19 convalescents at 12 months after infection with ancestral virus. In this cohort, ancestral, receptor-binding domain (RBD)-specific antibody and circulating memory B cell levels are conserved in most individuals, and yet serum neutralization against live B.1.1.529 (Omicron) is completely abrogated and significantly reduced for other VOCs. Likewise, ancestral SARS-CoV-2-specific memory T cell frequencies are maintained in >50% of convalescents, but the cytokine response in these cells to mutated spike epitopes corresponding to B.1.1.529 and B.1.351 (Beta) VOCs were impaired. These results indicate that increased antigen variability in VOCs impairs humoral and spike-specific T cell immunity post-infection, strongly suggesting that COVID-19 convalescents are vulnerable and at risk of re-infection with VOCs, thus stressing the importance of vaccination programs.

17.
Front Immunol ; 13: 884879, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35669767

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exhibits variable immunity responses among hosts based on symptom severity. Whether immunity in recovered individuals is effective for avoiding reinfection is poorly understood. Determination of immune memory status against SARS-CoV-2 helps identify reinfection risk and vaccine efficacy. Hence, after recovery from COVID-19, evaluation of protective effectiveness and durable immunity of prior disease could be significant. Recent reports described the dynamics of SARS-CoV-2 -specific humoral and cellular responses for more than six months in convalescent SARS-CoV-2 individuals. Given the current evidence, NK cell subpopulations, especially the memory-like NK cell subset, indicate a significant role in determining COVID-19 severity. Still, the information on the long-term NK cell immunity conferred by SARS-CoV-2 infection is scant. The evidence from vaccine clinical trials and observational studies indicates that hybrid natural/vaccine immunity to SARS-CoV-2 seems to be notably potent protection. We suggested the combination of plasma therapy from recovered donors and vaccination could be effective. This focused review aims to update the current information regarding immune correlates of COVID-19 recovery to understand better the probability of reinfection in COVID-19 infected cases that may serve as guides for ongoing vaccine strategy improvement.


Assuntos
COVID-19 , Vacinas contra COVID-19 , Humanos , Imunidade , Reinfecção , SARS-CoV-2
18.
Ann Thorac Med ; 17(2): 81-86, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35651891

RESUMO

INTRODUCTION: There are limited direct data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) long-term immune responses and reinfection. This study aimed to evaluate the rate, risk factors, and severity of COVID-19 reinfection. METHODS: This retrospective cohort study included five hospitals across Saudi Arabia. All subjects who were presented or admitted with positive SARS-CoV-2 real-time polymerase chain reaction (RT-PCR) tests were evaluated between March 2020 and August 2021. Reinfection was defined as a patient who was infected followed by clinical recovery, and later became infected again 90 days post first infection. The infection was confirmed with a positive SARS-CoV-2 (RT-PCR). Four hundred and seventeen recovered cases but with no reinfection were included as a control. RESULTS: A total of 35,288 RT-PCR-confirmed COVID-19 patients were observed between March 2020 and August 2021. Based on the case definition, (0.37%) 132 patients had COVID-19 reinfection. The mean age in the reinfected cases was 40.95 ± 19.48 (range 1-87 years); Females were 50.76%. Body mass index was 27.65 ± 6.65 kg/m2; diabetes and hypertension were the most common comorbidities. The first infection showed mild symptoms in 91 (68.94%) patients; and when compared to the control group, comorbidities, severity of infection, and laboratory investigations were not statistically different. Hospitalization at the first infection was higher, but not statistically different when compared to the control group (P = 0.093). CONCLUSION: COVID-19 reinfection is rare and does not carry a higher risk of severe disease. Further studies are required, especially with the continuously newly emerging variants, with the unpredictable risk of reinfection.

19.
J Med Virol ; 2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35655391

RESUMO

The coronavirus disease-19 (COVID-19) pandemic became the greatest public health challenge globally. In our study, it was aimed to determine the antibody levels in the third month after the COVID-19 infection and the symptoms that continued until the third month from the onset of the infection. One hundred people who applied to Tarsus State Hospital with the suspicion of COVID-19 and were positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by real-time reverse transcriptase-polymerase chain reaction were included. We collected serum samples from individuals, who were 3 months postinfection, and tested them in anti-SARS-CoV-2 Quanti-Vac ELISA IgG kit coated with recombinant S1 antigen for testing SARS-CoV-2 antibodies. Antibody levels were found to be higher in those aged ≥55 years, nonsmokers, those with comorbidities, and those who were hospitalized. The four most common symptoms that individuals initially encounter; are weakness, muscle and joint pain, loss of taste and smell, and cough. In 3 months after COVID-19 infection, the most common four symptoms are; muscle and joint pain, insomnia, fatigue, and other problems were determined. In conclusion; more research is needed to determine threshold levels of serum antibodies that could prevent reinfection of SARS-CoV-2.

20.
Results Phys ; 38: 105653, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35664991

RESUMO

Reinfection and reactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have recently raised public health pressing concerns in the fight against the current pandemic globally. In this study, we propose a new dynamic model to study the transmission of the coronavirus disease 2019 (COVID-19) pandemic. The model incorporates possible relapse, reinfection and environmental contribution to assess the combined effects on the overall transmission dynamics of SARS-CoV-2. The model's local asymptotic stability is analyzed qualitatively. We derive the formula for the basic reproduction number ( R 0 ) and final size epidemic relation, which are vital epidemiological quantities that are used to reveal disease transmission status and guide control strategies. Furthermore, the model is validated using the COVID-19 reported situations in Saudi Arabia. Moreover, sensitivity analysis is examined by implementing a partial rank correlation coefficient technique to obtain the ultimate rank model parameters to control or mitigate the pandemic effectively. Finally, we employ a standard Euler technique for numerical simulations of the model to elucidate the influence of some crucial parameters on the overall transmission dynamics. Our results highlight that contact rate, hospitalization rate, and reactivation rate are the fundamental parameters that need particular emphasis for the prevention, mitigation and control.

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