A recent article in the Daily Mail carries this very long headline, “Why ARE COVID cases plummeting? New infections have fallen by 45 percent in the U.S. and 30 percent globally in the past three weeks but experts say the vaccine is NOT the main driver because only eight percent of Americans and 13 percent of people worldwide have received their first dose. ”
The story goes on to recount the opinions of various experts as to why cases are dropping. It finally comes to the conclusion that the drop is likely due to a higher number of people who’ve had the virus than official counts suggest and that as many as 90 million people in the U.S. may have already been infected.
But these experts may have missed an important factor that led to this decrease: the test that is used to diagnose the presence of COVID-19 in patients has been changed recently to make it less sensitive.
A Polymerase Chain Reaction or PCR test detects genetic material from the COVID-19 virus. It can find the presence of a virus if you are infected at the time of the test. The PCR test can also detect fragments of the virus even after you are no longer infected. The test swabs are placed into a machine called a thermocycler which uses temperature to denature or separate the DNA of the virus and then replicate it using an enzyme