Background COVID-19 is rapidly spreading causing extensive burdens across the world. Effective vaccines to prevent COVID-19 are urgently needed. Methods and findings Our objective was to assess the effectiveness and safety of COVID-19 vaccines through analyses of all currently available randomized clinical trials. We searched the databases CENTRAL, MEDLINE, Embase, and other sources from inception to June 17, 2021 for randomized clinical trials assessing vaccines for COVID-19. At least two independent reviewers screened studies, extracted data, and assessed risks of bias. We conducted meta-analyses, network meta-analyses, and Trial Sequential Analyses (TSA). Our primary outcomes included all-cause mortality, vaccine efficacy, and serious adverse events. We assessed the certainty of evidence with GRADE. We identified 46 trials; 35 trials randomizing 219 864 participants could be included in our analyses. Our meta-analyses showed that mRNA vaccines (efficacy, 95% [95% confidence interval (CI), 92% to 97%]; 71 514 participants; 3 trials; moderate certainty); inactivated vaccines (efficacy, 61% [95% CI, 52% to 68%]; 48 029 participants; 3 trials; moderate certainty); protein subunit vaccines (efficacy, 77% [95% CI, −5% to 95%]; 17 737 participants; 2 trials; low certainty); and viral vector vaccines (efficacy 68% [95% CI, 61% to 74%]; 71 401 participants; 5 trials; low certainty) prevented COVID-19. Viral vector vaccines decreased mortality (risk ratio, 0.25 [95% CI 0.09 to 0.67]; 67 563 participants; 3 trials, low certainty), but comparable data on inactivated, mRNA, and protein subunit vaccines were imprecise. None of the vaccines showed evidence of a difference on serious adverse events, but observational evidence suggested rare serious adverse events. All the vaccines increased the risk of non-serious adverse events. Conclusions The evidence suggests that all the included vaccines are effective in preventing COVID-19. The mRNA vaccines seem most effective in preventing COVID-19, but viral vector vaccines seem most effective in reducing mortality. Further trials and longer follow-up are necessary to provide better insight into the safety profile of these vaccines.

Objective Gustatory sweating (GS) is characterized by profuse sweating during or immediately after ingestion of food and is known as a complication of diabetes mellitus (DM). This study aimed to determine the prevalence of GS and to characterize the sweating in a cohort of patients with type 1 and type 2 diabetes mellitus (T1DM and T2DM) as compared with a control group. Methods In a cross‐sectional study, 665 outpatients with T1DM and 505 outpatients with T2DM filled in an 8‐point questionnaire about GS. Answers were paired with medical data from the electronic patient records to explore associations with DM complications. The control group consisted of 1158 persons without DM answering the same questionnaire in an online version. Results In people with T1DM and T2DM, the prevalence of GS was 10% (95% CI 7%–12%) and 13% (95% CI 10%–16%), respectively. In the control group, the prevalence of GS was 5% (95% CI 3%–6%). Most commonly, people sweat on the face and/or head and upper body with a duration of 10–30 min albeit in the control group <10 min. In patients with T1DM, increased HbA1c was associated with GS (OR 1.3 [95% CI 1.05–1.6], p = .016), and in T2DM, younger age (OR 0.95 [95% CI 0.92–0.99), p = .006), presence of severe peripheral neuropathy (OR 2.33 [95% CI 1.04–5.2], p = .039) and absence of proliferative retinopathy were associated with GS (OR 0.22 [95% CI 0.07–0.71], p = .011). Conclusion We found the prevalence of gustatory sweating of 11% in a hospital‐based cohort of patients with T1DM and T2DM. This was twice as high as in non‐diabetic control persons. Associations between GS and known diabetes complications could only be demonstrated in T2DM. Compared with a control group without DM, odds for GS are higher in people with DM and age >45.