Thread by @AbraarKaran

-The reversal in #covid19 trends in Michigan & the Northeast seen below

~15% or so of the country is vaccinated
~30m confirmed cases from natural infection

-some overlap between those two groups (recovered who got vaxx)

-*many* still susceptible

npr.org/816707182

2/ Seroprevalence studies also indicate that we are under-detecting cases based on discordance b/w rtPCR and antibody studies; these numbers have varied at different time points in the year- all the way up to 10x by some measures at some time points #covid19

3/ One of the big questions is to what extent we have underlying immunity from un-detected cases, & to what extent that contributed to rapid declines in case numbers in January/Feb. Even so, that wouldn't be the whole story; physical distancing & other control measures matter.

4/ As we have seen many times, once you start to see reversal in trends, you likely have many more cases that are happening & going undetected still ('tip of the iceberg'); the infections you detect now likely happened a week or so ago depending on sx onset-->test interval

5/ Further delays between case detection --> hospitalization, given the clinical course of the disease.

In Michigan, we have seen now a reversal in cases AND hospitalizations; Connecticut, Massachusetts, NJ & others w/ similar reversals as well. #covid19

6/ While we are vaccinating fast, some states much faster/more efficiently than others, at this point- vaccinating alone without any other preventative measures will likely not prevent another surge in my opinion. Weather getting better in many places- we should take advantage

7/ Let this conversation not digress into lockdowns v no lockdowns; there is a lot in between. Avoid large indoor crowded poorly ventilated spaces if you/your loved ones are not vaccinated, esp if you have high risk people in your circles who are not vaccinated yet. #covid19

8/ Keep up masking esp in indoor crowded spaces in public; this is a very low hanging fruit; this won't be forever, but we need to bolster our vaccination efforts with all of our other prevention measures. Cloth+ surgical; or high filtration if you have it
nytimes.com/2021/03/03/opi…

9/ In short, many of us are concerned.

I am also optimistic; we have vaccinated many of those who are highest risk of death (65+)-- although even here long way to go (see CDC data at link below broken down demographically)

#covid19

covid.cdc.gov/covid-data-tra…

10/ We have evidence in the real world that vaccines work extremely well; in medical centers, nursing homes, in countries like Israel that are far ahead of the pack.

Vaccines excellent at preventing severe disease/death; also reduce asymptomatic infections #covid19