evidence: The reason Covid-19 tests continue to work when other tools don’t, such as the vaccines and monoclonal antibodies that have become ineffective over time, is that the vaccines and antibodies target the spike proteins that stick up from the round envelope of the virus. These spikes are under constant pressure from the environment to change, and they do. Most rapid tests, on the other hand, target the nucleocapsid proteins, or N-protein, of the coronavirus. N-proteins don’t change as much as spike proteins do. [...] Covid-19 cases were confirmed by PCR tests, which were helpful in determining a person’s viral load.