Hydroxychloroquine or chloroquine, often in combination with a second-generation macrolide, are being widely used for treatment of COVID-19, despite no conclusive evidence of their benefit. Although generally safe when used for approved indications such as autoimmune disease or malaria, the safety and benefit of these treatment regimens are poorly evaluated in COVID-19.
We did a multinational registry analysis of the use of hydroxychloroquine or chloroquine with or without a macrolide for treatment of COVID-19. The registry comprised data from 671 hospitals in six continents. We included patients hospitalised between Dec 20, 2019, and April 14, 2020, with a positive laboratory finding for SARS-CoV-2. Patients who received one of the treatments of interest within 48 h of diagnosis were included in one of four treatment groups (chloroquine alone, chloroquine with a macrolide, hydroxychloroquine alone, or hydroxychloroquine with a macrolide), and patients who received none of these treatments formed the control group. Patients for whom one of the treatments of interest was initiated more than 48 h after diagnosis or while they were on mechanical ventilation, as well as patients who received remdesivir, were excluded. The main outcomes of interest were in-hospital mortality and the occurrence of de-novo ventricular arrhythmias (non-sustained or sustained ventricular tachycardia or ventricular fibrillation).
Few studies have examined what happened to child survival when DTP and OPV were introduced in low-income countries. These vaccines were introduced in 1981 in an urban community in Guinea-Bissau from 3 months of age in connection with 3-monthly weighing sessions. Children were therefore allocated by birthday to receive vaccines early or late between 3 and 5 months of age. In this natural experiment vaccinated children had 5-fold higher mortality than not-yet-DTP-vaccinated children. DTP-only vaccinations were associated with higher mortality than DTP + OPV vaccinations. Hence, DTP may be associated with a negative effect on child survival.