I do not know of any viruses that by themselves attack red blood cells, because red blood cells do not contain their own nuclei by the time they enter circulation. The lack of nuclei in red blood cells is also why there's no such thing as red blood cell cancer. Considering viruses depend on the host cell's nucleic acid replication machinery to multiply, it is implausible that Sars-Cov-2 would target a red blood cell for any reason.

Furthermore, I think most people do not appreciate just how much smaller an oxygen molecule is compared to an entire protein. The idea that a protein could seal off all 4 heme groups from oxygen has me extremely skeptical. Additionally, there's hundreds of millions of hemoglobins per red blood cell. There's simply no way something as big as a virus could block an adequate number of heme groups from being available for oxygen. It's like saying a gate could stop ants from getting into your yard. This is nothing like carbon monoxide, which is a very similar size to oxygen and binds to iron orders of magnitude more tightly than oxygen.

On a different note, let's keep in mind that Sars-Cov-2 has an extremely high level of homology with Sars-Cov, or simply the SARS virus that spread throughout the world in the 2000s, both in the genome and the spike protein found on the virus which is key for the virus to enter a cell. The spike protein on the virus binds to the ACE-II protein, which is mainly expressed on lung cells and the small intestine.

I appreciate the experience and expertise that doctors on the board share on here, but frankly, there's a lot of bad science going viral on social media because educated lay people or even medical doctors simply do not understand biochemistry and lack the ability to sniff out explanations that do not pass the smell test. This paper: https://chemrxiv.org/articles/COVID-19_Disease_ORF8_and_Surface_Glycoprotein_Inhibit_Heme_Metabolism_by_Binding_to_Porphyrin/11938173 that got shared here last night and even SWG said was being shared with all his colleagues is not worthy of serious consideration.