This isn’t hysteria, and I don’t think hysteria is called for.
If smallpox had these numbers, well, that is a different story. But smallpox has had likely thousands of years to evolve higher infectivity, and seems to have reached a local maxima that isn’t there. Covid still has time to explore options.
Those appear to have greatly reduced the basic replication rate to around .9-1.3 or so shortly afterwards. As they are very severe countermeasures, it’s disingenuous to use the reduced replication rate ‘raw’ as no one is going to be doing them ‘naturally’.
The delta variant (B.1.617.2), now dominant in California and elsewhere, is approximately 2x more infectious than that original variant from the data I’ve found, which is limited [easiest thing I could fine here was https://www.npr.org/sections/goatsandsoda/2021/05/07/9947104...].
Outdoor infection IS less likely - this study of infected construction workers show only 1.4% of their outdoor only co-workers were infected by infected workers, where 43% of people they lived with and 26% of people they had indoor contact with while working got infected. There are many documented cases of outdoor infections, and even more where no known source could be found and all indoor or other sources were ruled out.
New variants driving up infectivity will of course drive this number up over
time if infections are allowed to spread (albeit hopefully vaccination can cut it off at the knees).
What does this mean? Without a vigorous public health response, Covid will continue to spread. It may continue to spread despite a very rigorous response from authorities because the body count is going to be low enough that many people just won’t care.
If we get an unfortunate deadlier variant, then maybe that will change. But one thing appears sure - we’re past the point (if there ever was one) where there is anything easy or pleasant that is going to happen.
Smallpox has been eradicated since the 1970s. There is no other data, and the data that exists doesn't support your assertion. A paper from 2001 is up to date.
Citing point estimates for SARS-CoV2 is not a rebuttal; there are many such estimates, and as I said, they're specific to time and place. The best you can do is compare distributions and look for general trends.
> The delta variant (B.1.617.2), now dominant in California and elsewhere, is approximately 2x more infectious than that original variant from the data I’ve found...That would put it (in a ‘natural’ setting) at R0 being roughly 12-13
You're just making things up. You can't take an old estimate, multiply it by some arbitrary factor, and draw a conclusion from it.
If you measure a (possibly representative) subset of a population (not all of NYC was measured) it's not uncommon to describe that as estimation, not measuring.
R0 unfortunately turns out to be a basically meaningless number for COVID. In theory it is a natural property of the virus. Other measures of R like Rt are then the 'adjusted' rates that take into account environmental factors.
In reality none of these numbers have any scientific validity, as they are usually computed using methodologies that aren't valid. In particular R0 is often simply a free variable in a model, i.e. a fudge factor in which the values are brute forced until the model output comes into line with reported government statistics. What does this fudge factor represent, if anything? Nobody actually knows, so it gets labelled R and then announced as a "fact" by epidemiologists. But then someone else takes a slightly different data set and runs the same calculation, but with a totally different R0 value coming out the other end.
This isn’t hysteria, and I don’t think hysteria is called for.
If smallpox had these numbers, well, that is a different story. But smallpox has had likely thousands of years to evolve higher infectivity, and seems to have reached a local maxima that isn’t there. Covid still has time to explore options.
Measured R0 in New York for COVID was 6.4 [https://www.medrxiv.org/content/10.1101/2020.05.17.20104653v...] for the original strain before lockdown and masking.
Those appear to have greatly reduced the basic replication rate to around .9-1.3 or so shortly afterwards. As they are very severe countermeasures, it’s disingenuous to use the reduced replication rate ‘raw’ as no one is going to be doing them ‘naturally’.
The delta variant (B.1.617.2), now dominant in California and elsewhere, is approximately 2x more infectious than that original variant from the data I’ve found, which is limited [easiest thing I could fine here was https://www.npr.org/sections/goatsandsoda/2021/05/07/9947104...].
That would put it (in a ‘natural’ setting) at R0 being roughly 12-13. Measles is estimated to have a R0 of 12-18. [https://pubmed.ncbi.nlm.nih.gov/28757186/]
Outdoor infection IS less likely - this study of infected construction workers show only 1.4% of their outdoor only co-workers were infected by infected workers, where 43% of people they lived with and 26% of people they had indoor contact with while working got infected. There are many documented cases of outdoor infections, and even more where no known source could be found and all indoor or other sources were ruled out.
New variants driving up infectivity will of course drive this number up over time if infections are allowed to spread (albeit hopefully vaccination can cut it off at the knees).
What does this mean? Without a vigorous public health response, Covid will continue to spread. It may continue to spread despite a very rigorous response from authorities because the body count is going to be low enough that many people just won’t care.
If we get an unfortunate deadlier variant, then maybe that will change. But one thing appears sure - we’re past the point (if there ever was one) where there is anything easy or pleasant that is going to happen.