eco's bones
Registered User
I think this is the essence of why so many early models were completely ridiculous.
Its described in this report:
https://www.medrxiv.org/content/10.1101/2020.04.27.20081893v1.full.pdf
Many persons are just not susceptible to a virus. You beat it at the door step so to speak. As people get infected and subsequently immune, it simultaneously reduce the virus ability to reproduce itself. With a voluntary vaccination program, if you vaccinate 10% you can count on that the virus R0 value is reduced 10%. You will have vaccinated both people susceptible to the virus as well as people that are not susceptible to the virus, so the effect is just 10%.
With disease-induced immunity, you get a positive benefit from the natural selection. The persons most likely to get the virus will become immune first on average of course.
So to calculate on the true impact of disease-induced immunity you must multiply it with a coefficient. They don't know what that is yet, but the best comparables they can find indicates a coefficient of 2 to 4.
At the bottom line this has a huuuge impact. If 10% of a population have disease-induced immunity -- a coefficient of 4 gives you a direct reduction of the R factor of 40%. With limited restrictions you should surely be able to bring down the R value to a range where 40% effective immunity brings the R0 value below 1, meaning that cases cannot grow.
If the Liverpool study is correct, it basically means that all places can have cases that goes up towards 10% of the population, but after that it will start to drop pretty rapidly with just limited social distancing efforts. It will be a huge positive factor when NYC opens up again...
There are still questions about immunity or even limited immunity in respect to this virus. The virus also seems to have morphed off in different directions as recently seen in the new cases appearing among children, teenagers and younger adults. IMO what we're seeing now in NYS (even if not so much in other states) are structures being put in place to take on a second wave of this virus or other future pandemics. Ramping up testing and tracing, coordinating and sorting out issues between public and private hospitals, a primer on how to set public health and safety policy in a time of pandemic which also should mean learning from mistakes made and not repeating them the next time, also understanding the importance to not be caught short again on medical equipment and supplies again and hopefully we will start producing and manufacturing much of those things ourselves in the future instead of being dependent on other nations.
There is a prevalent mindset in the United States particularly among the political elites that health care is not a human right and that it should be subject in pretty much every aspect to for profit enterprises. This has hampered our responding to this pandemic in an organized way. Too many millions of people uninsured or underinsured worried that a trip to the doctor or a hospital is tantamount to financial ruin. Medical bills are the leading cause of bankruptcy in the United States. As well leaving the response up to 50 state governors to do as they will can only lead to an uncoordinated response. IMO this didn't have to be as bad or even as nearly as bad as it turned out to be for us. There are lessons to be learned and neither our health care system or our political response to the pandemic proved to be up to the job. It's why we have the most cases and it's why we have the most deaths. We need to have the structures in place and a coordinated political response the next time something like this happens.