Thread by @amaxsmith

Virginia Health Sec Dan Carey says data is incredibly complicated, no model is perfect, but working on it.
"This is not a crystal ball" change every day

He's briefing media on Virginia's models it is looking at

We are seeing presentations from RAND & UVA on different #COVID19 models - UVA, Penn's CHIME, Univ of Wash IHME models are the focus, which keep getting updated/changing

RAND's Carter Price: asymmetric risk on resource constraints – one too many ICU beds might cost a few thousand dollars – one too few costs lives – assumptions should be biased for that

Price explaining the differences among models in how they can reflect potential impacts of social distancing, other changes - and how that would impact infections, peaks on timing etc

UVA Model uses a different mix of data tied to flu spread, and more local-level data, which can help be more region-specific in the state. Like any other model for future, dependent on how forecast things like social distancing will work

Univ of Wash IHME model is statistical based on confirmed COVID-19 deaths extrapolated to ICU beds, ventilators w/data from many areas
Price: since this is statistical, can serve as a comparator to the other models to check on assumptions, but w/o much testing, could miss some

Concerns about models are peak may be projected too early/late
Models should improve as more widespread testing happens so there is better data available & better US data
Price likes UVA/IHME models for forecasting, CHIME as hospital planning support tool; best to consider all

UVA scientists say they've had about 85 people looking at this through Biocomplexity Institute
They're trying to project infections in Virginia through end of summer, and consider how any social distancing/other measures could help

Goal not to precisely project future cases

UVA's Bryan Lewis says current social distancing efforts are working, and Virginia "as a whole" has enough medical resources for at least next few months, but lifting social distancing too soon would quickly lead to second wave of infections

UVA's model assumes initial 15% detection rate due to lack of early testing
They have considerations of future based on social distancing slowing growth (increasing cases, but not exponentially), social distancing pausing growth (new case numbers stay flat)
Pausing best match now

Estimating social distancing impact in Virginia, UVA looks at location data showing significant;y reduced activities.
Believe Va changes have cut rate of transmission - from about 2.2 before Mar 15 to about 1.1 per case after March 15th - cuts from 30% growth rate to 3% growth

UVA model projects short-term to May 1 is keeping confirmed new cases steady for next few weeks thanks to social distancing measures, but that the future depends on policies/social distancing measures

Projections under current information would put Virginia peak around Aug/September if social distancing orders were lifted Jun 10 and things remained paused, or around June/July if slow growth. With no controls, peak would be late May or with lifting Apr 30 peak would be summer

For planning purposes, Northern Virginia projected to go far beyond bed capacity first in mid-July and well into August/September and beyond range if social distancing lifted Jun 10 and it's paused growth pattern

If social distancing were lifted sooner than Jun 10, with no other mitigation, UVA projects hospitals would be overwhelmed in just a few weeks.
They are still adding more pieces to their models

Sec Carey: Social distancing is working, but we're in it for the long haul
Optimistic about hospital capacity, still working with hospital systems on space, equipment and staffing
Need to be cautious about a second surge, and careful about how we ease social distancing

On whether COVID-19 has seasonal aspect - hard to know at this point, but current consensus UVA model is based on it being potentially slightly seasonal but that won't have enough of an impact to get rid of the virus, might just help buy some more time

UVA model predicts a peak somewhere between July and September if everything lifted Jun 10 and things start to get back to normal with no other mitigations in place

That's even assuming that after lifting restrictions Jun 10, people only return about halfway to normal - still work from home if they can etc
UVA's Madhav Marathe emphasizes people will change action, so hope is never reach the peaks if people are careful

Sec Carey says definitely need additional strategies with more testing, temperature checks, contact tracing, and ways to do it in Virginia/US to control this longer-term
Can't just open everything or open halfway

Sec Carey also says would need to develop triggers over next few months that would reinstate face covering recommendations, or other changes, if after things start to reopen there's another resurgence