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bioRxiv · 10.1101/2021.10.02.462862

In Vitro Activity of Cysteamine Against SARS-CoV-2 Variants Alpha, Beta, Gamma and Delta

Thoene, J. G.·Gavin, R. F.·Towne, A.·Wattay, L.·Ferrari, M. G.·Pal, R.
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Abstract

Global COVID-19 pandemic is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Continuous emergence of new variants and their rapid spread are jeopardizing vaccine countermeasures to a significant extent. While currently available vaccines are effective at preventing illness associated with SARS-CoV-2 infection, these have been shown to be less effective at preventing breakthrough infection and transmission from a vaccinated individual to others. Here we demonstrate broad antiviral activity of cysteamine HCl in vitro against major emergent infectious variants of SARS-CoV-2 in a highly permissible Vero cell line. Cysteamine HCl inhibited infection of wild type, alpha, beta, gamma, delta, lambda, and omicron variants effectively. Cysteamine is a very well-tolerated US FDA-approved drug used chronically as a topical ophthalmic solution to treat ocular cystinosis in patients who receive it hourly or QID lifelong at concentrations 6 to 10 times higher than that required to completely inhibit SARS CoV-2 in tissue culture. Application of cysteamine as a topical nasal treatment can potentially1) mitigate existing infection 2) prevent infection in exposed individuals, and 3) limit the contagion in vulnerable populations.

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Thoene, J. G., Gavin, R. F., Towne, A., Wattay, L., Ferrari, M. G., Pal, R.. 2021-10-04. In Vitro Activity of Cysteamine Against SARS-CoV-2 Variants Alpha, Beta, Gamma and Delta. https://doi.org/10.1101/2021.10.02.462862

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