Impact of time elapsed since full vaccination on SARS-CoV-2 RNA load in Delta-variant breakthrough COVID-19.
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ABSTRACT:
SUBMITTER: de Michelena P
PROVIDER: S-EPMC8743856 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Waning humoral immunity after mRNA vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a significant problem for public health. Breakthrough infection in hospitals over several months after vaccination has not been fully characterized, especially against the delta (B.1.617.2) variant. Here, we describe an outbreak in our hospital in September of 2021, mainly through serological evaluation of the breakthrough infection. This retrospective observational study was done at an emergency and acute care hospital with 204 beds and 486 staff members where most staff members (92.6%) had had their second BNT162b2 vaccination by May of 2021. The peri-infection anti-spike RBD protein IgG (anti-S IgG) titers (lowest values between 11 days before and 7 days after onset or diagnosis) of serum samples from the breakthrough-infected persons were quantified. We also logarithmically estimated the anti-S IgG titers during the exposure period in September of uninfected staff members from their samples collected in May and December 2021. Whole-genome sequencing was done on obtained samples. In this outbreak, twelve persons (ten inpatients and two staff members) were diagnosed with SARS-CoV-2 infection by Loop-Mediated Isothermal Amplification (LAMP) or RT-PCR, eight of whom had been vaccinated twice. Peri-infection anti-S IgG titers could be determined in seven of the eight breakthrough cases, with a geometric mean titer (GMT) of 1,034 AU/ml (95% confidence interval [CI], 398 to 2,686). Among 289 uninfected staff members with data from the two sampling points, the GMT of the estimated anti-S IgG titers during the exposure period in 51 staff members, who were working at the outbreak ward and potentially exposed but uninfected, and 238 other unexposed staff members were 1,458 AU/ml (95% CI, 1,196 to 1,777) and 1,628 AU/ml (95% CI, 1,500 to 1,766), respectively. All viruses from the eight samples for which whole-genome sequencing was available were identified as delta variants. Of the infected persons, one remained asymptomatic throughout the course of treatment, and eleven had an illness of mild to moderate severity, including ten who received monoclonal antibody cocktail (Casirivimab/imdevimab) therapy. Measurement and estimation of anti-spike antibody levels after SARS-CoV-2 vaccination would be helpful for evaluating the risk of breakthrough infection and for determining the necessity of booster vaccination.
| S-EPMC9312404 | biostudies-literature
Project description:The Delta variant of SARS-CoV-2 has caused many breakthrough infections in fully vaccinated individuals. While vaccine status did not generally impact the number of viral RNA genome copies in nasopharyngeal swabs of breakthrough patients, as measured by Ct values, it has been previously found to decrease the infectious viral load in symptomatic patients. We quantified the viral RNA, infectious virus, and anti-spike IgA in nasopharyngeal swabs collected from individuals asymptomatically infected with the Delta variant of SARS-CoV-2. Vaccination decreased the infectious viral load, but not the amount of viral RNA. Furthermore, vaccinees with asymptomatic infections had significantly higher levels of anti-spike IgA in their nasal secretions compared to unvaccinated individuals with asymptomatic infections. Thus, vaccination may decrease the transmission risk of Delta, and perhaps other variants, despite not affecting the amount of viral RNA measured in nasopharyngeal swabs.
| S-EPMC9503182 | biostudies-literature
Project description:The Delta variant of concern of severe acute respiratory syndrome coronavirus 2 is dominant worldwide. We report a case cluster caused by Delta sublineage B.1.617.2 harboring the mutation E484K in Italy during July 11-July 29, 2021. This mutation appears to affect immune response and vaccine efficacy; monitoring its appearance is urgent.
| S-EPMC8632179 | biostudies-literature
Project description:ImportanceVaccine breakthrough by an emergent SARS-CoV-2 variant poses a great risk to global public health.ObjectiveTo determine the SARS-CoV-2 variant responsible for 6 cases of vaccine breakthrough.DesignNasopharyngeal swabs from suspected vaccine breakthrough cases were tested for SARS-CoV-2 by qPCR for Wuhan-Hu1 and Alpha variant. Positive samples were then sequenced by Swift Normalase Amplicon Panels to determine the causal variant.SettingTransmission event occurred at events surrounding a wedding outside of Houston, TX. Two patients from India, likely transmitted the Delta variant to other guests.ParticipantsFollowing a positive SARS-CoV-2 qPCR test at a third-party site, six fully vaccinated patients were investigated. Three males and three females ranged from 53 to 69 years old. One patient suffered from diabetes while three others were classified as overweight. No significant other comorbidities were identified. None of the patients had a history of failed vaccination.Key pointsQuestion: Which SARS-CoV-2 variant is responsible for 6 cases of vaccine breakthrough, one interventional monoclonal antibody treatment, and one death?Findings: Viral sequencing revealed 6 vaccinated patients were infected with the Delta SARS-CoV-2 variant. With no histories of vaccine breakthrough, this suggests Delta variant may possess immune evasion in patients that received the Pfizer BNT162b2, Moderna mRNA-1273, and Covaxin BBV152.Meaning: Delta variant may pose the highest risk out of any currently circulating SARS-CoV-2 variants, with increased transmissibility over Alpha variant and possible vaccine breakthrough.
| S-EPMC8282118 | biostudies-literature
Project description:BackgroundThis study aims to identify the causative strain of SARS-CoV-2 in a cluster of vaccine breakthroughs. Vaccine breakthrough by a highly transmissible SARS-CoV-2 strain is a risk to global public health.MethodsNasopharyngeal swabs from suspected vaccine breakthrough cases were tested for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) by qPCR (quantitative polymerase chain reaction) for Wuhan-Hu1 and alpha variant. Positive samples were then sequenced by Swift Normalase Amplicon Panels to determine the causal variant. GATK (genome analysis toolkit) variants were filtered with allele fraction ≥80 and min read depth 30x.ResultsViral sequencing revealed an infection cluster of 6 vaccinated patients infected with the delta (B.1.617.2) SARS-CoV-2 variant. With no history of vaccine breakthrough, this suggests the delta variant may possess immune evasion in patients that received the Pfizer BNT162b2, Moderna mRNA-1273, and Covaxin BBV152.ConclusionsDelta variant may pose the highest risk out of any currently circulating SARS-CoV-2 variants, with previously described increased transmissibility over alpha variant and now, possible vaccine breakthrough.FundingParts of this work was supported by the National Institute of Allergy and Infectious Diseases (1U19AI144297) and Baylor College of Medicine internal funding.
| S-EPMC8483940 | biostudies-literature
Project description:ObjectivesThe SARS-CoV-2 Delta variant (B.1.617.2) is associated with increased infectivity. Data on breakthrough SARS-CoV-2 Delta variant infections in vaccinated individuals and transmission risk are limited. The aim of this study was to provide estimates of transmission risk in Delta variant breakthrough infections.Study designA matched case-control study was performed..MethodsTo analyse onward transmission of fully vaccinated individuals infected with B.1.617.2, we compared 85 patients (vaccination group [VG]) with an age- and sex-matched unvaccinated control group (CG; n = 85).ResultsTransmission of B.1.617.2 was significantly reduced (halved) in the VG. The number of infected contacts to total number of contacts per infected person was 0.26 ± 0.40 in the VG vs 0.56 ± 0.45 in the CG (P = .001). Similarly, fully vaccinated contacts were less likely to be infected by fully vaccinated infected persons (IPs) than by unvaccinated IPs (20.0% vs 37.5%), although this association was not significant.ConclusionsFully vaccinated contacts had 50% less transmissions than unvaccinated individuals. These findings must be verified in larger sample populations, and it is especially important to investigate the role of vaccination status of close contacts.
| S-EPMC8747938 | biostudies-literature
Project description: Not available
| S-EPMC8641954 | biostudies-literature
Project description:Background: Post infection immunity and post vaccination immunity both confer protection against COVID-19. However, there have been many whole genome sequencing proven reinfections and breakthrough infections. Both are most often mild and caused by Variants of Concern (VOC). Methods: The patient in our study underwent serial COVID-19 RT-PCR, blood tests for serology, acute phase reactants, and chest imaging as part of clinical care. We interviewed the patient for clinical history and retrieved reports and case papers. We retrieved stored RT-PCR positive samples for whole genome sequencing (WGS) of SARS-CoV-2 from the patient's breakthrough infections and the presumed index case. Findings: The patient had three RT-PCR confirmed SARS-CoV-2 infections. Two breakthrough infections occurred in quick succession with the first over 3 weeks after complete vaccination with COVISHIELD and despite post-vaccination seroconversion. The first breakthrough infection was due to the Alpha variant and the second due to the Delta variant. The Delta variant infection resulted in hypoxia, hospitalization, and illness lasting seven weeks. Serial serology, acute phase reactants, and chest imaging supported WGS in establishing distinct episodes of infection. WGS established a fully vaccinated family member as the index case. Interpretation: The patient had an Alpha variant breakthrough infection despite past infection, complete vaccination, and seroconversion. Despite boosting after this infection, the patient subsequently had a severe Delta variant breakthrough infection. This was also a WGS proven reinfection and, therefore, a case of breakthrough reinfection. The patient acquired the infection from a fully vaccinated family member.
| S-EPMC8418387 | biostudies-literature
Project description: Not available
| S-EPMC8372487 | biostudies-literature
Project description:IntroductionCOVID-19 vaccines are expected to provide effective protection. However, emerging strains can cause breakthrough infection in vaccinated individuals. The immune response of vaccinated individuals who have experienced breakthrough infection is still poorly understood.MethodsHere, we studied the humoral and cellular immune responses of fully vaccinated individuals who subsequently experienced breakthrough infection due to the Delta variant of SARS-CoV-2 and correlated them with the severity of the disease.ResultsIn this study, an effective humoral response alone was not sufficient to induce effective immune protection against severe breakthrough infection, which also required effective cell-mediated immunity to SARS-CoV-2. Patients who did not require oxygen had significantly higher specific (p=0.021) and nonspecific (p=0.004) cellular responses to SARS-CoV-2 at the onset of infection than those who progressed to a severe form.DiscussionKnowing both humoral and cellular immune response could allow to adapt preventive strategy, by better selecting patients who would benefit from additional vaccine boosters.Trial registration numbershttps://clinicaltrials.gov, identifier NCT04355351; https://clinicaltrials.gov, identifier NCT04429594.
| S-EPMC10101330 | biostudies-literature