Shionogi Antiviral Pill Cuts COVID-19 Infection Risk in Exposed Household Contacts

Shionogi's experimental COVID-19 pill reduced the risk of infection among people exposed to the disease at home, according to a study published on Thursday. The antiviral has, for the first time, been shown to prevent COVID-19 in people exposed to the SARS-CoV-2 virus.

The company reported that the pill lowered infection rates among household contacts of confirmed cases. The findings come from a clinical trial that tracked participants who had been exposed to the virus within their homes. Researchers compared outcomes between those who received the pill and those who did not.

Participants took the oral antiviral shortly after exposure to an infected household member. The pill targets viral replication, aiming to stop the virus before an infection becomes established. The study provides data on both efficacy and safety in a post-exposure setting. Full results appeared in a scientific journal, though specific numerical reductions were not detailed in initial reporting.

Antivirals have primarily been used to treat COVID-19 after symptoms appear. This trial shifts focus toward preventive applications for those at high risk of exposure. The company has not announced immediate regulatory submissions based on the preventive data.

Further review by health authorities would be required before any label expansion for post-exposure prophylaxis. Interest in oral antivirals had declined after initial waves of the pandemic as vaccination rates rose and immunity increased. The new preventive results may prompt renewed evaluation of their role in outbreak control.