The Canadian Sentinel Practitioner Surveillance Network (SPSN) data reveal mid-season vaccine effectiveness (VE) against the SARS-CoV-2 Omicron XBB.1.5 variant of 47% against medically attended outpatient COVID-19 and 67% among previously infected people.

The same test-negative case-control study reports that the flu vaccine is 63% effective against medically attended outpatient infection with the influenza A H1N1 strain and 40% against H3N2.

The researchers enrolled patients with new or worsening cough that is characteristic of acute respiratory illness (ARI) who sought care within 7 days of symptom onset from community-based sentinel practitioners in Alberta, British Columbia (BC), Ontario, or Quebec.