Inclusion Criteria:  Age ≥ 18 years old and <80 years old Planned length of hospital stay in infectious disease department ≥ 48 hours Indication for vaccination against pneumococcus according to the 2013 HAS recommendations Vaccination planned as part of the usual care Patient hospitalized for sepsis meeting the sepsis criteria according to the latest consensus of 2016 or SIRS ≥ 2 with documented infection Patient having signed the free and informed consent form Subject affiliated to social security  Exclusion Criteria:  Pregnant or breastfeeding women, Vulnerable people Pneumococcal vaccination according to the prime-boost scheme already carried out less than 5 years old Pneumovax vaccination <1 year Known hypersensitivity to the active substances or to any of the excipients or to diphtheria toxoid. IgG level> 1 µg / mL among more than 75% of serotypes at inclusion Withdrawal of consent