It was already invented [0], but the patents were bought by a small company in New Zealand (some kind of big pharma shell company?) who isn't seriously developing it and now appears to be defunct.
replies(2):
""" In March 2024 Kimer Med announced it has signed a contract valued at up to USD$750,000 (NZD$1.3 million) with Battelle Memorial Institute (Battelle), the world’s largest independent, nonprofit research and development organization. The contract is focused on the discovery and development of new antiviral drug candidates for the treatment of alphaviruses. """
https://en.wikipedia.org/wiki/History_of_virology#Discovery
Hippocrates could recommend elderberry for a bunch of ailments, but he didn't have the concept of a "universal antiviral".