Enanta Pharmaceuticals, Pardes Biosciences, Japan’s Shionogi & Co Ltd and Novartis AG said they have designed antivirals that specifically target the coronavirus while aiming to avoid potential shortcomings such as the need for multiple pills per day or known safety issues.

Infectious disease experts stressed that preventing COVID-19 through wide use of vaccines remains the best way to control the pandemic. But they said the disease is here to stay and more convenient treatments are needed here.

“We need to have oral alternatives for suppression of this virus. We have people who aren’t vaccinated getting sick, people whose vaccine protection is waning, and people who can’t get vaccinated,” said Dr. Robert Schooley, an infectious diseases professor at UC San Diego School of Medicine.

Pfizer and Merck, as well as partners Atea Pharmaceuticals and Roche AG have all said they could seek emergency approval for their COVID-19 antiviral pills this year.