Abstract
Background
The PROTECT study is a longitudinal cohort study initiated in July 2021 with weekly testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 4 states: Arizona, ...Florida, exas, and Utah. This study aims to examine vaccine-elicited antibody response against postvaccination SARS-CoV-2 infections.
Methods
Children aged 5–11 years had serum collected 14–59 days after their second dose of monovalent Pfizer-BioNTech coronavirus disease 2019 messenger RNA vaccine. Vaccine-elicited antibodies were measured using the area under the curve (AUC) and end-point titer using enzyme-linked immunosorbent assay (receptor-binding domain RBD and S2) and surrogate neutralization assays against ancestral (WA1) and Omicron (BA.2).
Results
79 vaccinated participants (33 41.7% female; median age, 8.8 years standard deviation, 1.9 years), 48 (60.8%) were from Tucson, Arizona; 64 (81.0%) were non-Hispanic white; 63 (80.8%) attended school in person; 68 (86.1%) did not have any chronic conditions; and 47 (59.5%) were infected after vaccination. Uninfected children had higher AUCs against WA1 (P = .009) and Omicron (P = .02). The geometric mean and surrogate neutralization titer above the limit of detection was 346.0 for WA1 and 39.7 for Omicron, an 8.7-fold decrease (P < .001). After adjustment of covariates in the WA1-specific model, we observed a 47% reduction in the odds of postvaccination infection for every standard deviation increase in RBD AUC (aOR, 0.53 95% confidence interval, .29–.97) and a 69% reduction in the odds of infection for every 3-fold increase in RBD end titer (0.31 .06–1.57).
Conclusions
Children with higher antibody levels experienced a lower incidence of postvaccination SARS-CoV-2 infection.
Children aged 5–11 years with higher antibody levels 14–59 days after a second dose of the Pfizer-BioNTech coronavirus disease 2019 messenger RNA had a lower incidence of postvaccination severe acute respiratory syndrome coronavirus 2 infection. Results were consistent when measured via antibody response or antibody neutralization.
Several reports demonstrated that SARS-CoV-2 variant-of-concern B.1.1.529 (Omicron) exhibits a high degree of escape from antibody neutralization. Therefore, it is critical to determine how well the ...second line of adaptive immunity, T cell memory, performs against Omicron. To that purpose, we analyzed a human cohort (n=327 subjects) of two- or three- dose messenger RNA (mRNA) vaccine recipients and COVID-19 post infection subjects. We report that T cell responses against Omicron were largely preserved. IFN-γ producing T cell responses remained equivalent to the response against the ancestral strain (WA1/2020), with some (~20%) loss in IL-2 single or IL-2+IFNγ+ poly-functional responses. Three-dose vaccinated participants had similar responses to Omicron relative to post COVID-19 participants and exhibited responses significantly higher than those receiving two mRNA vaccine doses. These results provide further evidence that a three-dose vaccine regimen benefits the induction of optimal functional T cell immune memory.
As population immunity to SARS-CoV-2 evolves and new variants emerge, the role and accuracy of antigen tests remain active questions. To describe recent test performance, the detection of SARS-CoV-2 ...by antigen testing was compared with that by reverse transcription-polymerase chain reaction (RT-PCR) and viral culture testing during November 2022-May 2023. Participants who were enrolled in a household transmission study completed daily symptom diaries and collected two nasal swabs (tested for SARS-CoV-2 via RT-PCR, culture, and antigen tests) each day for 10 days after enrollment. Among participants with SARS-CoV-2 infection, the percentages of positive antigen, RT-PCR, and culture results were calculated each day from the onset of symptoms or, in asymptomatic persons, from the date of the first positive test result. Antigen test sensitivity was calculated using RT-PCR and viral culture as references. The peak percentage of positive antigen (59.0%) and RT-PCR (83.0%) results occurred 3 days after onset, and the peak percentage of positive culture results (52%) occurred 2 days after onset. The sensitivity of antigen tests was 47% (95% CI = 44%-50%) and 80% (95% CI = 76%-85%) using RT-PCR and culture, respectively, as references. Clinicians should be aware of the lower sensitivity of antigen testing compared with RT-PCR, which might lead to false-negative results. This finding has implications for timely initiation of SARS-CoV-2 antiviral treatment, when early diagnosis is essential; clinicians should consider RT-PCR for persons for whom antiviral treatment is recommended. Persons in the community who are at high risk for severe COVID-19 illness and eligible for antiviral treatment should seek testing from health care providers with the goal of obtaining a more sensitive diagnostic test than antigen tests (i.e., an RT-PCR test).
What is already known on this topic? In June 2022, COVID-19 vaccines were authorized for use in children aged 6 months–5 years. Intent to vaccinate and vaccination rates in children have been low. ...What is added by this report? During July 2021–May 2022, in a longitudinal cohort of 393 children aged <5 years in four states, parental intent to vaccinate children against COVID-19 and perception of COVID-19 vaccine safety and effectiveness declined over a 3-month period, but intent to vaccinate and perceptions of vaccine safety returned to baseline after 6 months. What are the implications for public health practice? Identifying and addressing barriers to COVID-19 vaccination in children aged <5 years and educating parents about COVID-19 vaccine effectiveness and safety in young children are critical to increasing pediatric COVID-19 vaccination coverage.
Since the publication of "A Compendium of Strategies to Prevent Healthcare-Associated Infections in Acute Care Hospitals" in 2008, prevention of healthcare-associated infections (HAIs) has become a ...national priority. Despite improvements, preventable HAIs continue to occur. The 2014 updates to the Compendium were created to provide acute care hospitals with up-to-date, practical, expert guidance to assist in prioritizing and implementing their HAI prevention efforts. They are the product of a highly collaborative effort led by the Society for Healthcare Epidemiology of America (SHEA), the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise, including the Centers for Disease Control and Prevention (CDC), the Institute for Healthcare Improvement (IHI), the Pediatric Infectious Diseases Society (PIDS), the Society for Critical Care Medicine (SCCM), the Society for Hospital Medicine (SHM), and the Surgical Infection Society (SIS).
BACKGROUND
In 2011 and 2013, the National Blood Collection and Utilization Survey (NBCUS) revealed declines in blood collection and transfusion in the United States. The objective of this study was ...to describe blood services in 2015.
STUDY DESIGN AND METHODS
The 2015 NBCUS was distributed to all US blood collection centers, all hospitals performing at least 1000 surgeries annually, and a 40% random sample of hospitals performing 100 to 999 surgeries annually. Weighting and imputation were used to generate national estimates for units of blood and components collected, deferred, distributed, transfused, and outdated.
RESULTS
Response rates for the 2015 NBCUS were 78.4% for blood collection centers and 73.9% for transfusing hospitals. In 2015, 12,591,000 units of red blood cells (RBCs) (95% confidence interval CI, 11,985,000‐13,197,000 units of RBCs) were collected, and 11,349,000 (95% CI, 10,592,000‐11,747,000) were transfused, representing declines since 2013 of 11.6% and 13.9%, respectively. Total platelet units distributed (2,436,000; 95% CI, 2,230,000‐2,642,000) and transfused (1,983,000; 95% CI, 1,816,000 = 2,151,000) declined by 0.5% and 13.1%, respectively, since 2013. Plasma distributions (3,714,000; 95% CI, 3,306,000‐4,121,000) and transfusions (2,727,000; 95% CI, 2,594,000‐2,859,000) in 2015 declined since 2013. The median price paid per unit in 2015—$211 for leukocyte‐reduced RBCs, $524 for apheresis platelets, and $54 for fresh frozen plasma—was less for all components than in 2013.
CONCLUSIONS
The 2015 NBCUS findings suggest that continued declines in demand for blood products resulted in fewer units collected and distributed Maintaining a blood inventory sufficient to meet routine and emergent demands will require further monitoring and understanding of these trends.
There are limited data on whether hybrid immunity differs by count and order of immunity-conferring events (SARS-CoV-2 infection or COVID-19 vaccination). From a cohort of health care personnel, ...first responders, and other frontline workers in six US states, we examined heterogeneity of the effect of hybrid immunity on SARS-CoV-2 antibody levels.
Exposures included event-count (sum of infections and vaccine doses) and event-order, categorized into seven permutations of vaccination and/or infection. Outcome was level of serum binding antibodies against receptor binding domain (RBD) of the ancestral SARS-CoV-2 spike protein (total RBD-binding Ig), measured by enzyme-linked immunosorbent assay. Mean antibody levels were examined up to 365 days after each of the 1st-7th events.
Analysis included 5,793 participants measured from August 7, 2020 to April 15, 2023. Hybrid immunity from infection before one or two vaccine doses elicited modestly superior antibody responses after the 2nd and 3rd events (compared to infections or vaccine-doses alone). This superiority was not evident after the 4th and 5th events (additional doses). Among adults infected before vaccination, adjusted geometric mean ratios (95% CI) of anti-RBD early response (versus vaccinated-only) were 1.23 (1.14-1.33), 1.09 (1.03-1.14), 0.87 (0.81-0.94), and 0.99 (0.85-1.15) after the 2nd-5th events, respectively. Post-vaccination infections elicited superior responses: adjusted geometric mean ratios (95% CI) of anti-RBD early response (versus vaccinated-only) were: 0.93 (0.75-1.17), 1.11 (1.06-1.16), 1.17 (1.11-1.24), and 1.20 (1.07-1.34) after the 2nd-5th events, respectively.
Findings reflecting heterogeneity in antibody levels by permutations of infection and vaccination history could inform COVID-19 vaccination policy.
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