Prevention of COVID-19 in workers: preparation, precaution, and protection.

In May 2023 the World Health Organization (WHO) Director General announced the "end" of the COVID-19 Public Health Emergency of International Concern. Although the scale of the pandemic was unprecedented in living memory, it had not been unforeseen. Previous outbreaks of viral respiratory disease have shown important lessons regarding the need to protect healthcare workers (HCW), and research has also been undertaken into the relative effectiveness of control measures and their resource implications. Relevant guidance for worker protection, including HCW protection, which existed at the onset of the COVID-19 pandemic was disregarded both at international and national governmental levels. In many countries there were significant systemic flaws in strategy, culture, and resource availability, and hence in overall preparedness. When the pandemic struck, many experts and organizations advocated a precautionary approach with regard to worker protection, consistent with good occupational hygiene science, practice, and standards. In many Asian countries, protective measures were relatively stringent. However, many workers were left unprotected especially as the WHO, the United States, the United Kingdom, and other governments did not pursue adequate COVID-19 protective measures at work. As the pandemic progressed, improvements in protection were patchy. A notable lack of protection arose from the underestimation of the contribution of aerosol exposure to infection risks, particularly among HCWs providing routine care of potentially infectious patients. A disciplined strategy of source control, pathway control (such as ventilation), and receptor control notably Respiratory Protective Equipment is needed, as well as worldwide vaccination, to contend with this pandemic. Control measures appropriate to the risk of infections transmitted through the air will remain necessary in the longer term, as well as adaptations in the workplace to take account of long-term COVID-19 morbidity and new work practices.