BNT162b2 booster after heterologous prime-boost vaccination induces potent neutralizing antibodies and T cell reactivity against SARS-CoV-2 Omicron BA.1 in young adults.

In light of the decreasing immune protection against symptomatic SARS-CoV-2 infection after initial vaccinations and the now dominant immune-evasive Omicron variants, 'booster' vaccinations are regularly performed to restore immune responses. Many individuals have received a primary heterologous prime-boost vaccination with long intervals between vaccinations, but the resulting long-term immunity and the effects of a subsequent 'booster', particularly against Omicron BA.1, have not been defined. We followed a cohort of 23 young adults, who received a primary heterologous ChAdOx1 nCoV-19 BNT162b2 prime-boost vaccination, over a 7-month period and analysed how they responded to a BNT162b2 'booster'. We show that already after the primary heterologous vaccination, neutralization titers against Omicron BA.1 are recognizable but that humoral and cellular immunity wanes over the course of half a year. Residual responsive memory T cells recognized spike epitopes of the early SARS-CoV-2 B.1 strain as well as the Delta and BA.1 variants of concern (VOCs). However, the remaining antibody titers hardly neutralized these VOCs. The 'booster' vaccination was well tolerated and elicited both high antibody titers and increased memory T cell responses against SARS-CoV-2 including BA.1. Strikingly, in this young heterologously vaccinated cohort the neutralizing activity after the 'booster' was almost as potent against BA.1 as against the early B.1 strain. Our results suggest that a 'booster' after heterologous vaccination results in effective immune maturation and potent protection against the Omicron BA.1 variant in young adults.

China's Research Evaluation Reform: What are the Consequences for Global Science?

In the 1990s, China created a research evaluation system based on publications indexed in the Science Citation Index (SCI) and on the Journal Impact Factor. Such system helped the country become the largest contributor to the scientific literature and increased the position of Chinese universities in international rankings. Although the system had been criticized by many because of its adverse effects, the policy reform for research evaluation crawled until the breakout of the COVID-19 pandemic, which accidently accelerates the process of policy reform. This paper highlights the background and principles of this reform, provides evidence of its effects, and discusses the implications for global science.

Elucidating the role of procalcitonin as a biomarker in hospitalized COVID-19 patients.

Our objectives were to evaluate the role of procalcitonin in identifying bacterial co-infections in hospitalized COVID-19 patients and quantify antibiotic prescribing during the 2020 pandemic surge. Hospitalized COVID-19 patients with both a procalcitonin test and blood or respiratory culture sent on admission were included in this retrospective study. Confirmed co-infection was determined by an infectious diseases specialist. In total, 819 patients were included; 335 (41%) had an elevated procalcitonin (>0.5 ng/mL) and of these, 42 (13%) had an initial bacterial co-infection. Positive predictive value of elevated procalcitonin for co-infection was 13% while the negative predictive value was 94%. Ninety-six percent of patients with an elevated procalcitonin received antibiotics (median 6 days of therapy), compared to 82% with low procalcitonin (median 4 days of therapy) (adjusted OR:3.3, P < 0.001). We observed elevated initial procalcitonin in many COVID patients without concurrent bacterial co-infections which potentially contributed to antibiotic over-prescribing.

Early and Significant Reduction in C-Reactive Protein Levels After Corticosteroid Therapy Is Associated With Reduced Mortality in Patients With COVID-19.

BACKGROUND: Corticosteroids may be beneficial in a subset of patients with coronavirus disease 2019 (COVID-19), but predictors of therapeutic response remain unknown. C-reactive protein (CRP) is a routinely measured biomarker, and reduction in its levels after initiation of therapy may predict inpatient mortality. METHODS: In this retrospective cohort study, the charts of patients who were admitted to Montefiore Medical Center between March 10, 2020, and May 2, 2020 for the management of COVID-19 were examined. Of all patients who met inclusion criteria, patients who received corticosteroid treatment were categorized as CRP responders (≥50% CRP level reduction) and CRP nonresponders (<50% CRP level reduction) based on change in CRP within 72 hours of corticosteroid treatment initiation. The outcomes of interest were two-fold: (1) CRP response after treatment with corticosteroid, and (2) differences in mortality among patients with CRP response compared those without. RESULTS: Of 2,707 patients admitted during the study period, 324 received corticosteroid treatment. Of patients who received corticosteroid treatment, CRP responders had reduced risk of death compared with risk among CRP nonresponders (25.2% vs 47.8%; unadjusted odds ratio [OR], 0.37; 95% CI, 0.21-0.65; P <.001). This effect remained strong and significant after adjustment for potential confounders (adjusted OR, 0.27; 95% CI, 0.14-0.54; P <.001). CONCLUSION: Reduction in CRP by 50% or more within 72 hours of initiating corticosteroid therapy potentially predicts inpatient mortality. This may serve as an early biomarker of response to corticosteroid therapy in patients with COVID-19.