Table 2. Country-specific estimates of historical smallpox vaccine effectiveness (VE) against mpox, Denmark, the Netherlands, France and Spain, March–July 2022.

Country	Birth cohort^a	Number of cases with vaccination information	Proportion of the population vaccinated	Number of cases vaccinated	Proportion of vaccinated cases (%)	VE (95% CI)
Denmark	Born up to and including 1966	5	95%	5	100	NA (NA–100)
France	Born up to and including 1965	74	90%	54	73	70% (50–82)
The Netherlands	Born up to and including 1970	97	89%	80	82	42% (2–66)
Spain	Born up to and including 1969	131	90%	78	60	84% (77–88)

CI: confidence interval; NA: not ascertainable; VE: vaccine effectiveness.

^a Birth cohorts from before the smallpox vaccination programme was phased out in each country.