Smallpox vaccination may confer cross-protection to mpox. We evaluated vaccinia virus antibodies in 162 persons ≥50 years of age in Spain; 68.5% had detectable antibodies. Highest coverage (78%) was among persons 71-80 years of age. Low antibody levels in 31.5% of this population indicates that addressing their vaccination should be a priority.
Keywords: Spain; antibodies; immunosenescence; monkeypox; mpox; sexually transmitted infections; smallpox; vaccine; vaccinia; viruses; zoonoses.