Thread by @calonghurst

1/ COVID (@UCSanDiego) Chronicles - July 26, 2021

I had hoped to be done with these when I wrote the last one ~100 days ago, but the rate of positive #COVID19 tests @UCSDHealth is back to almost 4%, near the winter surge peak. So here we go again...🧵

https://twitter.com/calonghurst/status/1381515173328916480

2/ Fortunately, the number of patients hospitalized with #COVID19 @UCSDHealth is still relatively low at 22, but the uptick is worrisome, particularly with @SanDiegoCounty hospitalizations >200 again for the first time since March

https://twitter.com/calonghurst/status/1417980648279592962

3/ Of course the most important reason we are not seeing more inpatients with #COVID19 is that some of these new cases are so-called breakthrough infections that are far less likely to be severe or require hospitalization

4/ In fact, we may be overusing the term "breakthrough" since an asymptomatic or relatively mild case represents the vaccine "doing what it is designed to do — keep people out of the hospital and out of the morgue."
npr.org/sections/healt…

5/ Why this #COVID19 resurgence? 3 reasons:

🦠Delta variant is more transmissible
📉Vaccine effectiveness *may* be waning (unconfirmed)
💉Vaccine rates are below levels needed for herd immunity (which is higher for Delta)

Let's look at each...

6/ The delta variant is estimated to be roughly 2-3x as contagious as the original strain. On average, people with delta had ~1,000x more copies of the virus and took just 4 days to reach detectable levels compared to 6 in the original strain
npr.org/sections/goats…

7/ The ↑ transmissibility of delta decreases the efficacy of traditional contact tracing

🚨PSA: All Californians with smartphones should make sure #CANotify is enabled to receive anonymous and rapid notifications of potential exposures 🦠📲

https://twitter.com/calonghurst/status/1418631081574625285

8/ What about waning immunity from the vaccines? Israeli numbers still show strong protection against severe disease, but suggest diminished effectiveness against infection, which allows continued transmission of the virus across the population
nytimes.com/2021/07/23/sci…

9/ It is not clear whether ↓ vaccine effectiveness against infection in Israel is due to Delta or a natural waning of protection over time, but it is VERY clear that they still provide protection against serious disease #VaccinesWork #VaccinesSaveLives

10/ According to @Bob_Wachter, our colleagues @UCSFHospitals have NOT seen diminished effectiveness of the vaccine. We will have preliminary analysis of @UCSDHealth data to share soon

https://twitter.com/Bob_Wachter/status/1419515413344309248

11/ With <50% of the US population fully vaccinated, we have fallen short of levels needed for herd immunity, even in San Diego where ~69% of eligible individuals are fully vaccinated
cnn.com/2021/07/25/hea…

12/ @UCSDHealth employee vaccination rates are now ~90% and @Bob_Wachter reports that @UCSFHospitals is at 93% in advance of the @UofCalifornia vaccine mandate. I would not be surprised to see vaccination requirements soon for all hospital employees.

https://twitter.com/Bob_Wachter/status/1419515408055365640

13/ The "pandemic of the unvaccinated" threatens public health, and I expect to see a rapid rise in vaccine mandates, especially after @US_FDA grants full approval
nbcnews.com/politics/white…

14/ Restaurants and bars in LA and the SF Bay Area are already beginning to require vaccine verification, and I hope to see more of this soon as it rewards those who are fully vaccinated and incentivizes those who are not yet

https://twitter.com/calonghurst/status/1419058441327308806

15/ So what can you do? Get vaccinated, ask your family and friends to get vaccinated, and if you run a business, require your employees and ask your customers to be vaccinated! #VaccinesWork #VaccinesSaveLives