SARS CoV 2 dominating all earlier strains of human coronavirus

According to the data collected, 229E, NL63, OC43, HKU1 combined up a positivity rate of 0.75% in Canada nationwide, being very close to 0% except in Ontario where they are combining 1.81% positivity. In Ontario, SARS CoV 2 alone has positivity 3.2%. So it seems SARS CoV 2 is far more contagious than earlier strains of human coronavirus.

Canada respiratory virus report up to August 28

Ontario positivity rate

Yet another article that shows that we are protected pretty well from this virus with an immune response to past coronavirus colds. medicalxpress.com...

It actually has more content than the older articles have, like explaining how old people tend to have worse effects of the SARS-CoV-2 virus and the common cold.

a reply to: mikegaiser

It’s probably true but they’re definitely not sure. 2 of the 4 major coronaviruses weren’t discovered until after SARS and our shifting to coronavirus disease research. Plus, it is highly likely that there have been several pandemic level spreads of a SARS like or other coronavirus that we just missed because we weren’t looking or didn’t have the ability.

SARS-CoV-2 does have a unique spike, we’re still not sure where it came from aside from a bat. There is a portion of it that requires cleaving by a protein called furin in between the S1/S2 site that really makes it get into the ACE2 receptor. It increases binding strength, speed of entry, and helps it access the cell. It’s not required but it is the force multiplier that really helps separate it from others. The other SARS like coronaviruses don’t have this and the animal sources we analyze don’t have it either.

We are missing that link that made it jump so much in its ability to enter its target. But it was most likely a recombination event. What happens is there are two template sources for the genetic printer RdRp (RNA dependent RNA polymerase) to draw from. RdRp is a viral RNA copy machine protein, our cells can’t copy RNA so the virus generates RdRp right when it enters the cell. It is notoriously inaccurate and has no capacity for error correction like a DNA polymerase. So it bounces between the two template RNA strands from 2 different sources or viruses, and combines different portions into a single novel strand. Usually it would be trash compared to the original and outcompeted. But every once in awhile there is one unique brand new sequence that gives it an edge.