Report of the WHO biosafety and biosecurity inspection team of the Variola Virus maximum containment laboratories to the Centers for Disease Control and Prevention (CDC): Atlanta, Georgia, United States of America, 27 April-1 May 2026

Ensuring the safe and secure handling of variola virus remains a critical global public health priority, given its historical impact and the risks associated with its storage and research. This report describes the findings of a World Health Organization biosafety and biosecurity inspection conducted at the variola virus repository at the Centers for Disease Control and Prevention in April–May 2026, as part of the biennial inspection mandate established by World Health Assembly resolution WHA60.1.

The document outlines the inspection scope, methodology and assessment framework applied across key domains of biological risk management, including facility infrastructure, risk assessment systems, personnel competence, emergency preparedness and security measures. It examines operational practices through document review, facility inspection and engagement with staff, while also assessing progress since the previous inspection. Findings are categorized according to a structured scale, distinguishing observations and priority levels to support risk-based evaluation and continuous improvement. The report highlights sustained compliance with international biosafety and biosecurity standards, with no issues requiring immediate corrective action, while identifying areas for further strengthening and requesting a follow-up action plan. It is intended to inform policy-makers, technical experts and stakeholders involved in the oversight of high-containment laboratories.