TD3AD_R273Q for COVID-19

 TD3AD_R273Q has been reported as potentially beneficial for COVID-19 in the following study.
COVID-19 involves the interplay of 350+ viral and host proteins and factors providing many therapeutic targets. Scientists have proposed 10,000+ potential treatments. c19early.org analyzes 200+ treatments. We have not reviewed TD3AD_R273Q in detail.
Gonzales et al., Development of an ultrahigh affinity, trimeric ACE2 biologic as a universal SARS-CoV-2 antagonist, Communications Biology, doi:10.1038/s42003-025-08819-w
Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, utilizes membrane-bound, angiotensin-converting enzyme II (ACE2) for internalization and infection. We describe the development of a biologic that takes advantage of the proximity of the N-terminus of bound ACE2 to the three-fold symmetry axis of the spike protein to create an ultrapotent, trivalent ACE2 entry antagonist. Distinct disulfide bonds were added to enhance serum stability and a single point mutation was introduced to eliminate enzymatic activity. Through surface plasmon resonance, pseudovirus neutralization assays, and single-particle cryo-electron microscopy, we show this antagonist binds to and inhibits SARS-CoV-2 variants. We further show the antagonist binds to and inhibits a 2003 SARS-CoV-1 strain. Collectively, structural insight has allowed us to design a universal trivalent antagonist against all variants of SARS-CoV-2 tested, suggesting it will be active against the emergence of future mutants.