Research articles

Nahkuri et al. evaluate potential prognostic factors for COVID-19 mortality in a large US database of electronic health records. They find that fluid, pH and electrolyte imbalances – diagnosed at least one month prior to COVID-19 diagnosis – are associated with mortality.

Coutinho et al. use genomic and epidemiological data from Manaus, Brazil, to estimate the transmissibility and potential for reinfection with the SARS-CoV-2 variant-of-concern P.1 (gamma). Using mathematical modelling, the authors estimate that P.1 is 2.6 times more transmissible than previous SARS-CoV-2 variants circulating in Manaus and underlies a large proportion of reinfections in Manaus.

Wurzel et al. describe the kinetics of the immune response in relation to clinical and virological features in a 5-month old infant with congenital heart disease and severe COVID-19. The immune response was characterised by an elevated inflammatory response in the acute phase of infection, followed by Th2 skewing and prolonged T cell activation.

Kongsuphol et al. develop a paper-based, vertical flow assay to detect SARS-CoV-2 neutralizing antibodies. The point-of-care assay has comparable performance to lab-based tests and provides results in 10 min.

Campos et al. study the genetic aetiology of antidepressant side effects. Using data from the Australian Genetics of Depression study, the authors show that polygenic risk scores for traits such as BMI, insomnia and headaches have a shared genetic basis with side effects to commonly used antidepressant drugs.

Jeong et al. report a series of COVID-19 patients with hearing- and balance-related symptoms. The authors show that human and mouse inner ear tissues, as well as human inner ear cells and organoids derived from induced pluripotent stem cells, express SARS-CoV-2 entry factors, and that these in vitro models of the human inner ear are susceptible to SARS-CoV-2 infection

Zhang et al. develop a natural language processing approach, based on the BERT model, to extract linguistic information from chest X-ray radiography reports. The authors establish a 25-label classification system for abnormal findings described in the reports and validate their model using data from multiple sites.

Konigsberg et al. profile DNA methylation in blood samples from SARS-CoV-2 cases and controls. The authors use machine learning to classify infected vs. non-infected individuals and predict clinical outcomes related to disease severity.

Sachak-Patwa et al. estimate the risk of SARS-CoV-2 outbreaks in low prevalence settings following the removal of travel restrictions and other non-pharmaceutical interventions, with the Isle of Man and Israel as case studies. Using a branching process mathematical model, the authors show that even after a large proportion of the population is vaccinated, there remains a risk of local outbreaks from imported cases.

Dalle Carbonare et al. perform a serology study in participants with a prior infection of SARS-CoV-2 and those who are SARS-CoV-2-naïve, who received two doses of the Pfizer-BioNTech BNT162b2 vaccine. After a single dose they observe a quicker recall of pseudovirus neutralization titres in previously-infected participants and a potent IgA response in both groups that was not associated with serum neutralization titres.

Plontke et al. report data on the preservation of vestibular function in a series of patients undergoing surgical removal of intracochlear tumors. Using objective clinical tests, the authors show that in most patients the vestibular system can function normally despite major surgical trauma to the cochlea.

Ying et al. conduct a multi-instrument Mendelian randomization study looking at the link between aging and COVID-19 risk. They observe an association between genetic variation implicated in longevity and decreased risk of COVID-19 infection and hospitalization, with Notch signaling and immune system development loci found to be important in aging-related COVID-19 risk.

Wong and Ngan et al. characterize the expression and structural variation of SARS-CoV-2 subgenomic RNAs (sgRNAs) in diagnostic specimens from symptomatic and asymptomatic COVID-19 patients. In a series of genomic and transcriptomic analyses, the authors observe reduced sgRNA expression and a distinct set of structural deletions in asymptomatic infections compared with symptomatic infections.

Levi and Ubaldi et al. evaluate SARS-CoV-2 seroprevalence in a cohort of 4735 healthcare workers in northern Italy. In seropositive individuals, they show that antibodies are maintained over a period of 8 to 10 months and associate changes in antibody levels over this period with symptoms and specific subgroups of participants.

Nemira et al. study the genomic epidemiology and phylodynamics of SARS-CoV-2 in Belarus. They identify potential introduction routes of the virus from other countries, determine that during the first wave of the pandemic the number of infections was likely several times higher than reported case numbers, and estimate the impact of early non-pharmaceutical interventions on SARS-CoV-2 transmission.

de Figueiredo et al. perform a global exploratory study to estimate COVID-19 vaccination acceptance and its determinants based on a survey across 32 countries. With some exceptions, they find that factors associated with increased vaccine acceptance are male sex, age over 65, being highly educated, and a belief that their government is handling the pandemic well.

Leong et al. use a dual-energy mammography technique termed three-compartment breast imaging to study breast composition and detect malignant lesions. Combining compositional information with morphology-based computer-aided diagnosis improves breast cancer detection.

Hanlon et al. study the prevalence of frailty and multimorbidity in a cohort of 20,566 UK Biobank participants with type 2 diabetes aged between 40 and 72 years. They observe that, even in this relatively young population, people living with frailty and/or multimorbidity are at increased risk of adverse outcomes including mortality, major adverse cardiovascular events, and hypoglycaemia.

Wang et al. characterize the tissue distribution of SARS-CoV-2 viral infection and replication as well as the expression of host cell entry factors in postmortem samples from six patients with COVID-19. They report the co-existence of SARS-CoV-2 infection and host entry factors in multiple pulmonary and non-pulmonary tissues.

Shi et al. propose a weighted kernel density estimation model to estimate COVID-19 risk across communities in Hong Kong. The authors use this data to evaluate potential COVID-19 vaccine allocation strategies in different epidemic scenarios.