[Application of Hydrashift 2/4 daratumumab assay in eliminating interference of daratumumab on serum immunofixation electrophoresis]

Objective: To investigate the interference of daratumumab on immunofixation electrophoresis after treating plasma cell diseases and methods to eliminate the interference. Methods: Serum samples of eight patients with plasma cell diseases treated with daratumumab in Peking University People's Hospital from April 2020 to March 2021 were collected for standard immunofixation electrophoresis and Hydrashift 2/4 daratumumab assay. Results: After treatment, 81.3% (13/16) of the samples showed drug-induced monoclonal antibodies (IgG-κ) . The samples without drug-induced monoclonal bands were related to individual differences, administration intervals, and immunoglobulin levels. Among the samples with IgG-κ monoclonal bands, 76.9% (10/13) could be directly identified as endogenous or exogenous monoclonal bands by immunofixation electrophoresis, and the others (3/13) could be identified by Hydrashift 2/4 daratumumab assay. Conclusion: Hydrashift 2/4 daratumumab assay can remove the band of daratumumab on the immunofixation electrophoresis and help with efficacy evaluation.

Herd immunity induced by COVID-19 vaccination programs and suppression of epidemics caused by the SARS-CoV-2 Delta variant in China

Background

To allow a return to a pre-COVID-19 lifestyle, virtually every country has initiated a vaccination program to mitigate severe disease burden and control transmission. However, it remains to be seen whether herd immunity will be within reach of these programs.

Methods

We developed a data-driven model of SARS-CoV-2 transmission for China, a population with low prior immunity from natural infection. The model is calibrated considering COVID-19 natural history and the estimated transmissibility of the Delta variant. Three vaccination programs are tested, including the one currently enacted in China and model-based estimates of the herd immunity level are provided.

Results

We found that it is unlike to reach herd immunity for the Delta variant given the relatively low efficacy of the vaccines used in China throughout 2021, the exclusion of underage individuals from the targeted population, and the lack of prior natural immunity. We estimate that, assuming a vaccine efficacy of 90% against the infection, vaccine-induced herd immunity would require a coverage of 93% or higher of the Chinese population. However, even when vaccine-induced herd immunity is not reached, we estimated that vaccination programs can reduce SARS-CoV-2 infections by 53–58% in case of an epidemic starts to unfold in the fall of 2021.

Conclusions

Efforts should be taken to increase population’s confidence and willingness to be vaccinated and to guarantee highly efficacious vaccines for a wider age range.

Prediction of vaccine efficacy of the Delta variant

The emergence of SARS-CoV-2 variants have raised concerns over the protective efficacy of the current generation of vaccines, and it remains unclear to what extent, if any, different variants impact the efficacy and effectiveness of various SARS-CoV-2 vaccines. We systematically searched for studies of SARS-CoV-2 vaccine efficacy and effectiveness, as well as neutralization data for variants, and used a previously published statistical model to predict vaccine efficacy against variants. Overall, we estimate the efficacy of mRNA-1273 and ChAdOx1 nCoV-19 against infection caused by the Delta variant to be 25-50% lower than that of prototype strains. The predicted efficacy against symptomatic illness of the mRNA vaccines BNT162b2 and mRNA-1273 are 95.1% (UI: 88.4-98.1%) and 80.8% (60.7-92.3%), respectively, which are higher than that of adenovirus-vector vaccines Ad26.COV2.S (44.8%, UI: 29.8-60.1%) and ChAdOx1 nCoV-19 (41.1%, 19.8-62.8%). Taken together, these results suggest that the development of more effective vaccine strategies against the Delta variant may be needed. Finally, the use of neutralizing antibody titers to predict efficacy against variants provides an additional tool for public health decision making, as new variants continue to emerge.

[Prevalence of injury among children in 28 counties of 6 provinces in China in 2017]

Objective: To investigate the incidence of injuries among children aged 0-17 years from 28 counties in six provinces. Methods: According to the earlier study on data in different local areas and the current work plan, we selected the survey objects for a general survey on child injury prevalence in the last 12 months. The subjects included guardians of children who did not attend kindergartens, children from kindergartens, and primary school grades 1-3. Children from grades 4-6 primary school, junior high school, and senior high school were also included. Results: The overall rate of injured children was 4.83%, with the incidence of injuries as 5.75% in the last 12 months before the survey. Both the rate of injured children and incidence of injuries were higher in boys than that in girls. Children whose primary caregivers were relatives, grandparents, minors, or with an education level below the primary school had a relatively higher rate of both injured children and incidence of injuries. The first cause of child injury was fall. The time of child injury was mainly from June to October, mainly at home, with the main activity as playing. The significant injuries in children were contusion and abrasion, and the main parts injured were lower limbs, upper limbs, and head. Most of the injuries were cured, and the primary treatment was outpatient and emergency treatment. Conclusions: Boys and children whose parents can not take care of are the priority population for child injury prevention and control. Targeted prevention and control measures should be implemented according to the characteristics of injuries among children of different ages.

[The epidemiological characteristics and influencing factors of animal injuries among children from 28 counties in 6 provinces, China]

Objective: To understand the epidemiological characteristic and influencing factors of animal injuries among children from 28 counties/districts in 6 provinces of China to provide evidence for formulating related prevention measures and strategies. Methods: Data was obtained from 'Children injury prevention project, 2016-2020'. Variables on the characteristics, including incidence, locations, related activities, time, and outcomes among children, were described. The negative binomial regression model analyzed animal injury frequency influencing factors. Results: There were 107 029 boys and 97 599 girls, with a gender ratio of 1.10, among the 204 628 children aged 0-17 in 28 counties/districts in 6 provinces of China. Per-person and per-time incidence rates of animal injuries were 0.70% and 0.72%, both higher in boys than in girls. Animal injuries among children mainly occurred in home (73.20%), road/street (7.51%), and open space of community/village (6.77%), during playing (63.15%), with the peak time between 12:01-18:00 (45.03%). Upper limbs (47.89%), lower limbs (35.31%), and head (8.44%) were the most injured body parts. Outpatient or emergency treatment (85.19%) had been carried out. The negative binomial regression showed that sex, grade, guardian educational level, urban or rural, and daily communication between guardians and children as influencing factors in the frequency of animal injuries among children. Conclusions: Special attention should be given to boys, at home, in projects on animal injury prevention and control. There were many influencing factors of animal injury frequency. Knowledge of injury prevention should be popularized to children and guardians. Related comprehensive intervention should be developed in families, schools, and social settings.

[Prevalence and prevention of traffic injury among children in 28 counties of 6 provinces in China, 2017]

Objective: To investigate the incidence of traffic injuries among children aged 0-17 years in 28 counties of 6 provinces and to provide prevention suggestions. Methods: Using the general survey method, a questionnaire survey was conducted on the road traffic injuries of children in 28 counties of 6 provinces in 2017. Results: A total of 204 628 students were surveyed, 908 of whom had experiences of road traffic injuries. Road traffic injuries were 0.44% among children in 28 counties of 6 provinces in China and 0.94% among children who did not attend kindergartens. July is a high incidence period of road traffic injuries among children (12.92%). When children suffer from road traffic injuries, the first three activities were playing (21.61%), riding an electric bicycle (20.40%), walking (20.07%). Most injuries appeared as contusion/abrasion, accounting for 42.26% of the total cases. The injured parts were mainly lower limbs, upper limbs, and heads, accounting for 38.85%, 23.29%, and 20.20%. Most children with road traffic injuries recovered after related treatments, accounting for 85.43% of all cases. The median length of hospital stay of children with road traffic injuries was seven days, and the median expense in hospitals was 3 000 Yuan (RMB). Conclusions: The incidence of road traffic injuries among males appeared higher than females, and the children who did not attend the kindergartens were the highest. During playing, riding an electric bicycle and walking were the top three activities prone to road traffic injuries.

[An exploratory framework of vaccine hesitancy monitoring and early warning system in China]

Vaccine hesitancy has spread worldwide recent years and resulting in increasing incidence of some well-controlled vaccine-preventable diseases, which is extremely unfavorable to the consolidation of the national immunization programme and the elimination of corresponding diseases. Based on the Complacency, Convenience and Confidence ("3Cs") model of vaccine hesitancy, combined with the practice experience of management of quality control through the whole vaccine life cycle in China, we introduce a framework of vaccine hesitancy monitoring and early warning in China to provide a reference for carrying out corresponding work. The indicator system of the framework derives from monitoring of vaccine life cycle quality management, population vaccine confidence, and service availability.

Case Fatality Risk of the First Pandemic Wave of Coronavirus Disease 2019 (COVID-19) in China

Objective

To assess the case fatality risk (CFR) of COVID-19 in mainland China, stratified by region and clinical category, and estimate key time-to-event intervals.

Methods

We collected individual information and aggregated data on COVID-19 cases from publicly available official sources from December 29, 2019 to April 17, 2020. We accounted for right-censoring to estimate the CFR and explored the risk factors for mortality. We fitted Weibull, gamma, and lognormal distributions to time-to-event data using maximum-likelihood estimation.

Results

We analyzed 82,719 laboratory-confirmed cases reported in mainland China, including 4,632 deaths, and 77,029 discharges. The estimated CFR was 5.65% (95%CI: 5.50%-5.81%) nationally, with highest estimate in Wuhan (7.71%), and lowest in provinces outside Hubei (0.86%). The fatality risk among critical patients was 3.6 times that of all patients, and 0.8-10.3 fold higher than that of mild-to-severe patients. Older age (OR 1.14 per year; 95%CI: 1.11-1.16), and being male (OR 1.83; 95%CI: 1.10-3.04) were risk factors for mortality. The time from symptom onset to first healthcare consultation, time from symptom onset to laboratory confirmation, and time from symptom onset to hospitalization were consistently longer for deceased patients than for those who recovered.

Conclusions

Our CFR estimates based on laboratory-confirmed cases ascertained in mainland China suggest that COVID-19 is more severe than the 2009 H1N1 influenza pandemic in hospitalized patients, particularly in Wuhan. Our study provides a comprehensive picture of the severity of the first wave of the pandemic in China. Our estimates can help inform models and the global response to COVID-19.

Topographically guided hierarchical mineralization

Material platforms based on interaction between organic and inorganic phases offer enormous potential to develop materials that can recreate the structural and functional properties of biological systems. However, the capability of organic-mediated mineralizing strategies to guide mineralization with spatial control remains a major limitation. Here, we report on the integration of a protein-based mineralizing matrix with surface topographies to grow spatially guided mineralized structures. We reveal how well-defined geometrical spaces defined within the organic matrix by the surface topographies can trigger subtle changes in single nanocrystal co-alignment, which are then translated to drastic changes in mineralization at the microscale and macroscale. Furthermore, through systematic modifications of the surface topographies, we demonstrate the possibility of selectively guiding the growth of hierarchically mineralized structures. We foresee that the capacity to direct the anisotropic growth of such structures would have important implications in the design of biomineralizing synthetic materials to repair or regenerate hard tissues.

To what extent do we need to rely on non-pharmaceutical interventions while COVID-19 vaccines roll out in 2021?

COVID-19 vaccination is being conducted in over 190 countries/regions to control SARS-CoV-2 transmission and return to a pre-pandemic lifestyle. However, understanding when non-pharmaceutical interventions (NPIs) can be lifted as immunity builds up remain a key question for policy makers. To address it, we built a data-driven model of SARS-CoV-2 transmission for China. We estimated that to prevent the escalation of local outbreaks to widespread epidemics, stringent NPIs need to remain in place at least one year after the start of vaccination. Should NPIs alone be capable to keep the reproduction number (R _t ) around 1.3, the synergetic effect of NPIs and vaccination could reduce up to 99% of COVID-19 burden and bring R _t below the epidemic threshold in about 9 months. Maintaining strict NPIs throughout 2021 is of paramount importance to reduce COVID-19 burden while vaccines are distributed to the population, especially in large populations with little natural immunity.

Comprehensive mapping of neutralizing antibodies against SARS-CoV-2 variants induced by natural infection or vaccination

Background

Immunity after SARS-CoV-2 infection or vaccination has been threatened by recently emerged SARS-CoV-2 variants. A systematic summary of the landscape of neutralizing antibodies against emerging variants is needed.

Methods

We systematically searched PubMed, Embase, Web of Science, and 3 pre-print servers for studies that evaluated neutralizing antibodies titers induced by previous infection or vaccination against SARS-CoV-2 variants and comprehensively collected individual data. We calculated lineage-specific GMTs across different study participants and types of neutralization assays.

Findings

We identified 56 studies, including 2,483 individuals and 8,590 neutralization tests, meeting the eligibility criteria. Compared with lineage B, we estimate a 1.5-fold (95% CI: 1.0-2.2) reduction in neutralization against the B.1.1.7, 8.7-fold (95% CI: 6.5-11.7) reduction against B.1.351 and 5.0-fold (95% CI: 4.0-6.2) reduction against P.1. The estimated neutralization reductions for B.1.351 compared to lineage B were 240.2-fold (95% CI: 124.0-465.6) reduction for non-replicating vector platform, 4.6-fold (95% CI: 4.0-5.2) reduction for RNA platform, and 1.6-fold (95% CI: 1.2-2.1) reduction for protein subunit platform. The neutralizing antibodies induced by administration of inactivated vaccines and mRNA vaccines against lineage P.1 were also remarkably reduced by an average of 5.9-fold (95% CI: 3.7-9.3) and 1.5-fold (95% CI: 1.2-1.9).

Interpretation

Our findings indicate that the antibody response established by natural infection or vaccination might be able to effectively neutralize B.1.1.7, but neutralizing titers against B.1.351 and P.1 suffered large reductions. Standardized protocols for neutralization assays, as well as updating immune-based prevention and treatment, are needed.

Funding

Chinese National Science Fund for Distinguished Young Scholars.

Serological evidence of human infection with SARS-CoV-2: a systematic review and meta-analysis

BACKGROUND

A rapidly increasing number of serological surveys for antibodies to SARS-CoV-2 have been reported worldwide. We aimed to synthesise, combine, and assess this large corpus of data.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, Web of Science, and five preprint servers for articles published in English between Dec 1, 2019, and Dec 22, 2020. Studies evaluating SARS-CoV-2 seroprevalence in humans after the first identified case in the area were included. Studies that only reported serological responses among patients with COVID-19, those using known infection status samples, or any animal experiments were all excluded. All data used for analysis were extracted from included papers. Study quality was assessed using a standardised scale. We estimated age-specific, sex-specific, and race-specific seroprevalence by WHO regions and subpopulations with different levels of exposures, and the ratio of serology-identified infections to virologically confirmed cases. This study is registered with PROSPERO, CRD42020198253.

FINDINGS

16 506 studies were identified in the initial search, 2523 were assessed for eligibility after removal of duplicates and inappropriate titles and abstracts, and 404 serological studies (representing tests in 5 168 360 individuals) were included in the meta-analysis. In the 82 studies of higher quality, close contacts (18·0%, 95% CI 15·7-20·3) and high-risk health-care workers (17·1%, 9·9-24·4) had higher seroprevalence than did low-risk health-care workers (4·2%, 1·5-6·9) and the general population (8·0%, 6·8-9·2). The heterogeneity between included studies was high, with an overall I2 of 99·9% (p<0·0001). Seroprevalence varied greatly across WHO regions, with the lowest seroprevalence of general populations in the Western Pacific region (1·7%, 95% CI 0·0-5·0). The pooled infection-to-case ratio was similar between the region of the Americas (6·9, 95% CI 2·7-17·3) and the European region (8·4, 6·5-10·7), but higher in India (56·5, 28·5-112·0), the only country in the South-East Asia region with data.

INTERPRETATION

Antibody-mediated herd immunity is far from being reached in most settings. Estimates of the ratio of serologically detected infections per virologically confirmed cases across WHO regions can help provide insights into the true proportion of the population infected from routine confirmation data.

FUNDING

National Science Fund for Distinguished Young Scholars, Key Emergency Project of Shanghai Science and Technology Committee, Program of Shanghai Academic/Technology Research Leader, National Science and Technology Major project of China, the US National Institutes of Health.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

The significance of Hashimoto's thyroiditis for postoperative complications of thyroid surgery: a systematic review and meta-analysis

INTRODUCTION

Hashimoto's thyroiditis (HT) is one of the most common immune-mediated diseases. It makes thyroid surgery more complicated and difficult because there may be adhesions between the thyroid gland and surrounding structures. However, it is still controversial whether HT patients carry a high risk for postoperative complications of thyroid surgery. The purpose of this study was to investigate the significance of HT for the postoperative complications of thyroid surgery.

METHODS

A search for studies assessing the postoperative complication risks of HT patients compared with that of patients with benign nodules (BNs) was performed in PubMed, EMBASE and Web of Science. Nine studies (20,118 cases, 1,582 cases of HT and 18,536 cases of BN) were identified, and the data from the relevant outcomes were extracted and analysed.

RESULTS

There were no significant differences between the HT group and BN group in recurrent laryngeal nerve palsy (RLNP) and permanent hypoparathyroidism (PHP). The rate of transient hypocalcaemia (THC) was significantly higher in the HT group (16.85%) than in the BN group (13.20%).

CONCLUSIONS

The meta-analysis showed that HT only increased the risk of the postoperative complication THC compared to BN. Understanding the significance of HT in postoperative hypoparathyroidism after thyroid surgery would help clinicians perform sufficient preoperative (and postoperative) assessments and to optimise surgical planning.

Can a COVID-19 vaccination program guarantee the return to a pre-pandemic lifestyle?

COVID-19 vaccination programs have been initiated in several countries to control SARS-CoV-2 transmission and return to a pre-pandemic lifestyle. However, understanding when non-pharmaceutical interventions (NPIs) can be lifted as vaccination builds up and how to update priority groups for vaccination in real-time remain key questions for policy makers. To address these questions, we built a data-driven model of SARS-CoV-2 transmission for China. We estimated that, to prevent local outbreaks to escalate to major widespread epidemics, stringent NPIs need to remain in place at least one year after the start of vaccination. Should NPIs be capable to keep the reproduction number (Rt) around 1.3, a vaccination program could reduce up to 99% of COVID-19 burden and bring Rt below the epidemic threshold in about 9 months. Maintaining strict NPIs throughout 2021 is of paramount importance to reduce COVID-19 burden while vaccines are distributed to the population, especially in large populations with little natural immunity.

Association of Frailty Status with Risk of Fall among Middle-Aged and Older Adults in China: A Nationally Representative Cohort Study

OBJECTIVES

To investigate the association between frailty status and risk of fall among middle-aged and older Chinese people.

DESIGN

A nationally representative prospective cohort study.

SETTING AND PARTICIPANTS

The study included 13,877 community-dwelling participants aged 45 years and above from the China Health and Retirement Longitudinal Study.

METHODS

Frailty status was identified by the frailty index of health deficit accumulation. 34 variables at baseline were selected to calculate the frailty index. We excluded participants with incomplete information in construction of the frailty index at baseline. Falls were measured based on the respondents' self-report. We used a logistic regression model to estimate the associations between the frailty status and risk of fall, and subgroup analyses and sensitivity analyses were further conducted.

RESULTS

Of 13,877 participants, 2310 (16.6%) had falls during the observation period. 9027 (65.0%) participants were classified as robust, 4019 (29.0%) participants were classified as pre-frail, and 831 (6.0%) participants were classified as frail. Our results indicated per 0.01 increment in the frailty index was significantly associated with an increased risk of fall among middle-aged and older participants (OR: 1.52, 95%CI: 1.45-1.60). Such association was stronger when frailty was presented as a categorical variable, with an OR of 1.75 (95%CI: 1.59-1.93) for pre-frail and 3.04 (95%CI: 2.60-3.56) for frail. The area under the curve of the logistic model was 0.612 (95%CI: 0.600-0.625). Each 0.01 increment of the frailty index was association with a higher risk of fall among middle-aged (45-59years) participants (OR: 1.44, 95%CI: 1.29-1.60) than among older (≥60 years) participants (OR: 1.28, 95%CI: 1.16-1.41) at baseline (p=0.015 for interaction).

CONCLUSION

Frailty was significantly associated with an increased risk of fall among community-dwelling middle-aged and older people in China. It is necessary to screen and recognize frailty status to prevent falls among middle-aged and older adults.

Coronaviruses: Molecular Biology (Coronaviridae)

Coronaviruses (CoVs) are enveloped, positive-strand RNA viruses with characteristic spike glycoproteins that project outward like the rays of the sun (corona – Latin for ‘crown’), when visualized by electron microscopy. CoV are classified, together with the toroviruses, in the family Coronaviridae and the order Nidovirales. All nidoviruses have a common genome organization and generate a nested set (nido – Latin for ‘nest’) of 3′ co-terminal mRNAs. CoVs have been isolated from a variety of species, including birds, livestock, domestic animals, and humans. CoV infections can cause respiratory, gastrointestinal, and neurologic disease, depending on the strain of the virus and the site of infection. Importantly, CoVs have been shown to cross species barriers and have emerged from animal reservoirs to infect humans and cause severe disease. The CoV responsible for an outbreak of severe acute respiratory disease (SARS-CoV) in 2002–03 likely originated as a bat coronavirus which, during replication in an intermediate host (such as the palm civet), evolved to be able to infect humans efficiently. SARS-CoV infected over 8000 people with approximately 10% mortality rate before it was controlled by public health measures of isolation of infected individuals and contacts. Middle East Respiratory Syndrome CoV (MERS-CoV), first reported in 2012, is likely transmitted from camels to humans with potentially fatal consequences. To date, there are no approved vaccines or direct acting antiviral drugs to combat coronavirus infections in humans. The emergence or re-emergence of CoVs from animal reservoirs is a potential concern for public health.