COVID has not disappeared, and millions of Americans still face serious risk after a household member, caregiver, coworker, or close contact tests positive.

10-20% of people who get COVID-19 experience symptoms lasting more than 3 months, and ~5% get Long COVID fatigue that lasts longer than a year. 

Families need more tools to combat this virus, especially when older adults, immunocompromised people, people with chronic disease, or caregivers are involved.

Since 2022 people living in Japan have had access to Xocova, a once-daily SARS-CoV-2 antiviral that studies show is equivalent in efficacy to Paxlovid.  In March 2026, Japan also approved Xocova for prevention of COVID after exposure, making it the first oral antiviral available for COVID post-exposure prophylaxis.

In the Phase 3 SCORPIO-PEP trial, ensitrelvir reduced the risk of developing symptomatic COVID among initially uninfected household contacts after exposure. Shionogi reported a 67% risk reduction by Day 10. Paxlovid has also been tested for post-exposure prophylaxis, but failed to show a statistically significant benefit in a Phase 2/3 trial. 

Xocova may also fill important practical gaps left by Paxlovid:

• Paxlovid contains ritonavir, a strong CYP3A inhibitor, and the FDA label warns that this can increase exposure to many other medications, potentially causing serious or life-threatening drug interactions. This is one reason Paxlovid can be difficult to prescribe, especially for older or medically complex patients. Xocova does not require ritonavir boosting.
• Xocova is once daily and has a long half-life. Rebound after a 5 day course of Xocova is rare, while rebound after Paxlovid is common, affecting 15% or more of people. 
• Recent research suggests it is hard for the SARS-CoV-2 virus to evolve resistance to both Xocova and Paxlovid. 

We are not asking the FDA to lower its standards. We are asking the FDA to recognize the continuing public-health need, evaluate the evidence promptly and transparently, and approve ensitrelvir either for post-exposure prophylaxis or for SARS-CoV-2 infection. 

We call on the FDA to:

• Recognize the urgent need for an antiviral option to help prevent household and close-contact spread.
• Recognize the many benefits of having two effective SARS-CoV-2 antivirals on the market. 
• Approve Xocova/ensitrelvir  by the June 16, 2026 action date.
• Be fully transparent about precisely how their decision were made.