Instruct: Identify the main category of the given medRxiv paper based on its title.
Query: Methadone overdoses increased 48% during the COVID-19 epidemic
Exposure to per- and polyfluoroalkyl substances associates with altered lipid profile of breast milk
Pre-pandemic mental health and disruptions to healthcare, economic, and housing outcomes during COVID-19: evidence from 12 UK longitudinal studies
Generation time of the Alpha and Delta SARS-CoV-2 variants
Smartphone Camera Based Assessment of Adiposity: A Multi-Site Validation Study
Genetic scores explain variation in birthweight that is not captured by easily measured clinical and anthropometric variables
Within-host evolution of SARS-CoV-2 in an immunosuppressed COVID-19 patient: a source of immune escape variants
Indirect Effects of COVID-19 on Maternal, Neonatal, Child, Sexual and Reproductive Health Services in Kampala, Uganda
Clinical Variables Correlate with Serum Neutralizing Antibody Titers after COVID-19 mRNA Vaccination in an Adult, US-based Population
Pharmacokinetic /Pharmacodynamic Considerations of Alternate Dosing Strategies of Tocilizumab in COVID-19
Prevalence of Specific Multimorbidity Combinations and Association with Medical Expenditures and Perceived Health among U.S. Adults, 2016-2019
Single Prime hAd5 Spike (S) + Nucleocapsid (N) Dual Antigen Vaccination of Healthy Volunteers Induces a Ten-Fold Increase in Mean S- and N- T-Cell Responses Equivalent to T-Cell Responses from Patients Previously Infected with SARS-CoV-2
Emergence and spread of a SARS-CoV-2 variant through Europe in the summer of 2020
The Effects of Messaging on Expectations and Understanding of Long COVID: An Online Randomised Trial
Near-exact explicit asymptotic solution of the SIR model well above the epidemic threshold
Breaching the curation bottleneck with human-machine reading symbiosis
Effectiveness of COVID-19 vaccines against hospitalization and death in Canada: A multiprovincial test-negative design study
A highly sensitive and specific SARS-CoV-2 spike- and nucleoprotein-based fluorescent multiplex immunoassay (FMIA) to measure IgG, IgA and IgM class antibodies
Cost saving in primary versus tertiary level of reproductive health services in Sana'a, Yemen
Comparison of the Immunogenicity of five COVID-19 vaccines in Sri Lanka
Machine Learning based COVID-19 Diagnosis from Blood Tests with Robustness to Domain Shifts
Metformin Is Associated with Favorable Outcomes in Patients with COVID-19 and Type 2 Diabetes Mellitus
Direct and indirect mortality impacts of the COVID-19 pandemic in the US, March 2020-April 2021
Determinants of sleep quality in adults during the COVID-19 pandemic: COVID-Inconfidentes, a population-based study
An assessment of the vaccination of school-aged children in England
SARS-CoV-2 seroprevalence in children, parents and school personnel from June 2020 to April 2021: cohort study of 55 schools in Switzerland