Human Challenge Studies with Coronaviruses Old and New

Area of Science:

• Virology
• Immunology
• Epidemiology

Background:

• Human coronaviruses (HCoVs) cause diseases ranging from the common cold to severe illnesses like SARS, MERS, and COVID-19.
• Historically, HCoVs were under-studied due to mild symptoms, limiting understanding of reservoirs, transmission, and immunity.
• The emergence of SARS-CoV-2 has highlighted the need for deeper insights into HCoV pathogenesis and host responses.

Purpose of the Study:

• To review historical human infection challenge studies with HCoVs.
• To identify knowledge gaps in HCoV infection, protection, and pathogenesis.
• To highlight the significance of ongoing SARS-CoV-2 challenge studies for pandemic preparedness.

Main Methods:

• Analysis of existing literature on human coronavirus challenge studies.
• Review of methodologies used in controlled human infection models.
• Examination of immunological and clinical data from challenge studies.

Main Results:

• Human challenge studies have historically focused on common cold HCoVs.
• Studies on highly pathogenic HCoVs like SARS-CoV and MERS-CoV were previously limited.
• New SARS-CoV-2 challenge studies are underway to investigate susceptibility and immunity in controlled settings.

Conclusions:

• Human infection challenge studies are crucial for understanding HCoV immunity and pathogenesis.
• Contemporary studies, particularly with SARS-CoV-2, are vital for developing vaccines and antivirals.
• These research models are essential for preparedness against current and future HCoV outbreaks and pandemics.