Hospitalisation among vaccine breakthrough COVID-19 infections

Review of patients admitted to hospital with SARS-CoV-2 between 23rd Mar and 1 Jul 2021 (single US health economy, n=969) found 18% had at least 1 dose of COVID vaccine. Among those fully vaccinated, 46% were asymptomatic (incidental testing), and 26% had severe COVID-19.

SPS commentary:

Authors state the significant rate of severe disease in those who were vaccinated could be reflective of numerous factors, including the emergence of SARS-CoV-2 variants that might confer decreased vaccine effectiveness and an ineffective immune response mounted against vaccines among those with comorbidities—eg, older age, overweight, and use of immunosuppressive agents.

Authors also report a higher number of patients with severe or critical illness in those who received the Pfizer vaccine than in those who received Moderna vaccine, a finding that would benefit from further investigation.

The Lancet Infectious Diseases