Instruct: Identify the main category of the given Medrxiv paper based on the title.
Query: COVID-19 mortality in Italy varies by patient age, sex and pandemic wave
Microbiological risk ranking of foodborne pathogens and food products in scarce-data settings.
Remdesivir to treat COVID-19: can dosing be optimized?
Co-circulation of SARS-CoV-2 variants B.1.1.7 and P.1
Antibody Response to CoronaVac Vaccine in Indonesian COVID-19 Survivor
Animals in higher education settings: Do animal-assisted interventions improve mental and cognitive health outcomes of students?  A systematic review and meta-analysis
Mental sequelae of the Covid-19 pandemic: Well-being one year into the crisis in children with and without complex medical histories and their parents
Dysautonomia in hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorders is associated with exercise intolerance and cardiac atrophy
Impact of the COVID-19 pandemic on the mental health and wellbeing of parents with young children: a qualitative interview study
Previously infected vaccinees broadly neutralize SARS-CoV-2 variants
DNA methylation and general psychopathology in childhood: An epigenome-wide meta-analysis from the PACE consortium
The Relevance of Lactate Levels in Acute Seizure
Creation of a ustekinumab external control arm for Crohn's disease using electronic health records data: a pilot study
Covid-19 respiratory protection: the filtration efficiency assessment of decontaminated FFP2 masks responding to associated shortages
Estimation of the Lifetime Quality-Adjusted Life Years (QALYs) Lost Due to Syphilis acquired in the United States in 2018
Longitudinal analyses of depression and anxiety highlight greater prevalence during COVID-19 lockdowns in the Dutch general population and a continuing increase in suicidal ideation in young adults
Comparison of SARS-CoV-2 detection in Saliva by real-time RT-PCR and RT-PCR/MALDI-TOF Methods
Considerations for Developing and Implementing an Online Community-Based Exercise Intervention for Adults Living with HIV: a qualitative study
Real-world study of the effectiveness of BBIBP-CorV (Sinopharm) COVID-19 vaccine in the Kingdom of Morocco
Effectiveness and Safety of MSC Cell Therapies for Hospitalized Patients with COVID-19: A Systematic Review and Meta-analysis
Multimorbidity and its associated risk factors among the older adults in India
Changing of therapeutic trends between the 1st and 2nd wave did not reduce COVID-19 related mortality of renal transplant recipients: a national registry study.
Evaluation of lymphocyte subtypes in COVID-19 patients
A new SARS-CoV-2 variant poorly detected by RT-PCR on nasopharyngeal samples, with high lethality
Deep learning based electrocardiographic screening for chronic kidney disease
Spatial-temporal relationship between population mobility and COVID-19 outbreaks in South Carolina: A time series forecasting analysis