Informing the pandemic response: the role of the WHO's COVID-19 Weekly Epidemiological Update

Abstract

On 31 December 2019, the Municipal Health Commission of Wuhan, China, reported a cluster of atypical pneumonia cases. On 5 January 2020, the WHO publicly released a Disease Outbreak News (DON) report, providing information about the pneumonia cases, implemented response interventions, and WHO's risk assessment and advice on public health and social measures. Following 9 additional DON reports and 209 daily situation reports, on 17 August 2020, WHO published the first edition of the COVID-19 Weekly Epidemiological Update (WEU). On 1 September 2023, the 158th edition of the WEU was published on WHO's website, marking its final issue. Since then, the WEU has been replaced by comprehensive global epidemiological updates on COVID-19 released every 4 weeks. During the span of its publication, the webpage that hosts the WEU and the COVID-19 Operational Updates was accessed annually over 1.4 million times on average, with visits originating from more than 100 countries. This article provides an in-depth analysis of the WEU process, from data collection to publication, focusing on the scope, technical details, main features, underlying methods, impact and limitations. We also discuss WHO's experience in disseminating epidemiological information on the COVID-19 pandemic at the global level and provide recommendations for enhancing collaboration and information sharing to support future health emergency responses.

Keywords: COVID-19; Epidemiology; Public Health; Respiratory infections; SARS.

Figure 1

Examples of visual aids illustrating COVID-19 epidemiological trends. (A) Number of COVID-19 cases reported by WHO region and deaths by 28-day intervals, as of 1 September 2023. (B) Number of confirmed cases by country per 100 000 population, 31 July 2023–27 August 2023. Created by the WHO.

Figure 2

Examples of visual aids illustrating global COVID-19 cases, deaths, hospitalisations and ICU admissions reported weekly to WHO, as of 1 September 2023. The numbers of cases represented by the grey bars in the figure are only from countries reporting hospitalisations or ICU admissions, respectively. Created by the WHO. ICU, intensive care unit.

Figure 3

Timeline of global COVID-19 cases and dominant SARS-CoV-2 variants, 1 January 2020–1 September 2023. Created by the WHO, using data from WHO and GISAID. GISAID, Global Initiative on Sharing All Influenza Data; VOCs, variants of concern; VOIs, variants of interest; WEU, Weekly Epidemiological Update; * includes descendent lineages.

Figure 4

Examples of visual aids illustrating information on COVID-19 vaccine effectiveness (VE). (A) VE of primary series and booster vaccination against the Delta VOC. (B) VE of primary series and first booster vaccination against the Omicron VOC. Created by the WHO. VOC, variants of concern.

Figure 5

Overview of the WEU process, as of 1 September 2023. Created by the WHO. API, Application Programming Interface; GISAID, Global Initiative on Sharing All Influenza Data; ICU, intensive care unit; MoH, Ministries of Health; WEU, Weekly Epidemiological Update.