Ah yeah, I forgot even one iota of COVID is enough to infect an entire metropolitan area. Guess these dogs are goners.
You are right in a sense that a single Delta infected person with it’s R0 of 4 can infect a million other in only 9 host cycles. That is it only takes 9 jumps from host to host for a single Delta infected person to grow to a million infected in a unvaccinated population set of vectors. With an infectious window of 3 to 5 days for each generation that’s 45 days for a single case to grow to a million. India saw numbers at least that high they had places with an R0 of 6+. Here in the USA the additional factors would be a vaccine penetration rate of 30 to 40% and a case recovery rate of 25% or so have been exposed to the alpha, beta and gamma strains. Delta has the ability to jump past natural immunity to a certain degree there’s thousands of documented cases of people having recovered from the alpha beta or gamma strain and sickened by Delta confirmed with RNA sequencing of the secondary infectious strain. So the natural immunity factor for Delta is lower than 25% way lower it looks to be able to infect half of people who had the alpha and beta strain in numbers so far quantified. The Mrna vax antibodies are only 64% effective against Delta so the V penetration factor is also under 40% since 64% of that 40% are protected the rest are not. Factor in all those numbers and it would only take 12 generations with the USA vector set of.vulnerabilities to go from one case to a million of Delta it’s basic immunological mathematics well.defined and well studied.