A study of all fully vaccinated people in Belgium has assessed the risk factors associated with developing COVID-19 after vaccination. The research, which is being presented at this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Lisbon, Portugal, (23-26 April) and published in the journal Viruses, found that breakthrough infections were more common in those who had received viral vector vaccines than mRNA vaccines. Those who had previously had COVID had a lower risk of breakthrough infections.