Researchers from the Technical University of Munich in Germany and the University of Helsinki in Finland led a study that discovered a receptor called neuropilin-1 gives the novel coronavirus a leg-up in infecting our tissues. https://www.sciencealert.com/a-second-key-used-by-sars-cov-2-to-enter-cells-could-explain-why-it-s-so-infectious.
Why is it more infectious to men? Antibodies and Interferons with the X-Chromosome?