RecruitingClinical trialNeutralizing Power of Serum Antibodies - 2Severe forms of COVID-19 and Monkeypox affect immunocompromised and comorbid individuals. Vaccination and monoclonal antibody therapies induce neutralizing antibodies. This neutralizing power is recognized as a correlate of protection against a new infection. This study aims to describe the neutralizing power of serum and nasal antibodies over time, in relation to SARS-CoV-2 and MPXV vaccines or treatments received.