Venous blood was collected from both the children and mothers in EDTA-coated plain and heparinized vacutainer tubes, and transported at 2–8°C to the National Institute for Medical Research (NIMR) Korogwe Research Laboratory for further processing and laboratory analyses. Plasma was separated within 2 hours of collection in a refrigerated centrifuge. All samples were stored at −80°C and later shipped on dry ice to Rigshospitalet, Denmark for the detection of anti-SARS-CoV-2 antibodies by ELISA. High-sensitivity C-reactive protein (hs-CRP) was measured in the Department of Clinical Biochemistry, Copenhagen University Hospital, using the Cobas 8000 c702 system (Roche Diagnostics).
At the study site, point-of-care diagnostics were performed on the venous blood including the estimation of haemoglobin (Hb) (Sysmex KX-21N), fasting blood glucose (HemoCue 301), and malaria rapid diagnostic test (mRDT) (ParaHIT or CareStart Malaria Pf). For participants with a positive mRDT, the parasitaemia was confirmed by two independent expert microscopists. HIV infection was tested with the Determine HIV-1/2 test kit (Alere Ltd) and seropositive cases were confirmed using the Unigold test kit (Trinity Biotech Plc). All tests were done according to the manufacturer's instructions.
At the study site, point-of-care diagnostics were performed on the venous blood including the estimation of haemoglobin (Hb) (Sysmex KX-21N), fasting blood glucose (HemoCue 301), and malaria rapid diagnostic test (mRDT) (ParaHIT or CareStart Malaria Pf). For participants with a positive mRDT, the parasitaemia was confirmed by two independent expert microscopists. HIV infection was tested with the Determine HIV-1/2 test kit (Alere Ltd) and seropositive cases were confirmed using the Unigold test kit (Trinity Biotech Plc). All tests were done according to the manufacturer's instructions.