Rough Estimates: 100 Days to End the COVID-19 Threat in Ventura (Oxnard: how much, calculator)

[wac_432]

Though public officials won't come right out and say it, the plan seems to be to allow 60-80% of the population to become infected with COVID-19 in a "controlled" fashion and establish herd immunity before the fall influenza season. We can see this from the Governor's speech on reopening the economy where he referenced "Herd immunity" about 6 times, usually saying "when we reach herd immunity and a vaccine" or some similar phrase. Reasonable estimates put a vaccine at least a year away. In the mean time, San Buenaventura and Thousand Oaks can take steps to open their economies with social distancing and work toward getting over the virus without exceeding their hospital capacity.

Ventura has 2 hospitals: VCMC and CMH, with about 500 beds between them. They should be able to surge to at least clear those beds for COVID-19 cases, and hopefully double their capacity.

Based on the number of hospitalizations and deaths in LA county compared to the antibody tests showing 4.1% infection rate, the rough CFR (for the entire population) is 0.15%. Since children are very nearly immune to severe effects, and young people are also very low risk, this means that seniors and those with co-morbidities are at very elevated risk. Despite having influenza-similar numbers, COVID-19 is much more deadly for adults.

Currently, the lockdown has resulted in a nationwide reduced transmission rate of Rt=0.96. The unmitigated transmission rate of COVID-19 is anywhere between 2.6 and 6, though an average seems to be around 3. It is highly contagious and requires mitigation.

Given all this, the city of Ventura (population ~ 100,000) can expect:

If social distancing maintains an Rt of 1.6 (50-75% more social activity than the current "lockdown"), the peak hospitalization requirements will be about 560 beds, and will occur about 3 months from when restrictions are relaxed (94 days). 60% of the population will have acquired immunity around 140 days from the reduced restrictions, and further/complete opening could occur.

With more than twice as much social interaction as during the complete lockdown, (an Rt of 2.1) peak hospitalization will require about 980 beds and will occur after 74 days. 60% immunity will be achieved around 90 days after restrictions are reduced.

Completely unmitigated (100% open, no one wears masks, business as usual) and assuming an R0 of 3.1, peak hospitalization would require over 1500 beds (triple the city's current capacity), it would occur 54 days after restrictions were lifted, and 60% immunity would occur 60 days after restrictions were lifted.


These numbers are my personal estimates based on very preliminary data from limited antibody studies, public population and hospital capacity, and a basic epidemic simulator, however, I believe they are in the ballpark of what we can realistically expect. They would also apply to Thousand Oaks, as it has a similar population size and hospital capacity. I do not know about Simi Valley, Camarillo, or Oxnard/PH.

Announcement referencing antibody testing in LA county: https://content.govdelivery.com/acco...?reqfrom=share
Epidemic Calculator: https://gabgoh.github.io/COVID/index.html

[wac_432]

Also, based on the number of LA fatalities for their 4% infection rate, compared to the Ventura County fatality count, there appear to have been approximately 8600 cases of COVID-19 in the county, to date. That corresponds to about 1% of the population.

This would make sense, juxtaposed against LA's numbers, considering VC's lower population density should have resulted in slower spread prior to the shutdowns.

[SFBayBoomer]

Originally Posted by wac_432

Also, based on the number of LA fatalities for their 4% infection rate, compared to the Ventura County fatality count, there appear to have been approximately 8600 cases of COVID-19 in the county, to date. That corresponds to about 1% of the population.

This would make sense, juxtaposed against LA's numbers, considering VC's lower population density should have resulted in slower spread prior to the shutdowns.

Not enough testing has been done, not by a long shot, to determine how much of the population has been infected or to "make sense" of anything. We need to do a lot more testing.

I don't know anyone at all who has been tested, not for active infection, and certainly not for antibodies to the virus.

[wac_432]

Originally Posted by SFBayBoomer

Not enough testing has been done, not by a long shot, to determine how much of the population has been infected or to "make sense" of anything. We need to do a lot more testing.

I don't know anyone at all who has been tested, not for active infection, and certainly not for antibodies to the virus.

I 100% agree. Reliable and extensive antibody testing should be our number 1 priority.