“…Monkeypox virus infection stimulates humoral and cellular immune responses that restrict viral replication and induce long-term immunity in recovering patients. 4 , 64 , 65 , 66 , 67 , 68 Humoral immune response after natural infection with monkeypox or vaccinia virus vaccination consists of orthopoxvirus-specific IgM and IgG antibodies against multiple antigen targets with long-term persistence of residual IgG-memory B cells 4 , 65 , 67 that protects from reinfection or from developing severe disease. 4 After vaccinia virus vaccination, specific memory B cells can last for decades, although only 50% of individuals have protective concentrations of neutralising antibodies after 20 years.…”