Let's talk B117 and why I don't think this variant is going to deter our progress. What are 3 things you worry about with a variant? 1) Increased transmissibility; 2) Increased virulence; 3) Can escape immunity from your vaccine (or natural infection). Let's take them 1 at a time
1) Increased transmissibility: There is lab data showing higher viral loads with this variant in nose so could be more infectious. However please look at epidemiology on world stage and in U.S. to make your decisions. UK tamped down virus with vaccines with 90% of their strains
being B117 and never saw their dreaded surge once vaccine roll-out started; 2) Israel started rolling out vaccine with 80% of strains being B117, saw surge as we are seeing in some states here (will get to that in min.) but then tamped down with vaccine
3) And here in US, as I just tweeted, 5 US states have nearly 50% of cases (NY, MI, Fl, PA, NJ) but those states do not overlap cleanly with the states that have the highest prevalence of B117 or other variants of concern in the US (CA, CO, MN, MI, NH, FL)
as shown to us by this CDC map (cdc.gov/coronavirus/20…). So, not that simple and each state's cases probably reflective of their natural immunity (high in CA, TX after 3rd surge; low in MI as not as large surges) + vaccination rate Image
Okay 2) Increased virulence: The cleanest way to look at this in US is to look at states with highest prevalence of B117 and see if "hospitalization per case" rate has gone up. Meaning, if virus is more virulent, more cases will end up being hospitalized. Will call this ratio H/c
Let's look at H/c ratio for some of our states with highest prevalence of variants per CDC (FL, MI, MN, CO) - we don't want to be here all night so won't even bother with CA with such low cases/hospitalizations; effect of variants here is pretty obvious (eg. nil). Ok, here goes
MN (again, your H/c should go up if variants more deadly as variants spread from 2/25/21-4/6/21)
4/6/21: H/c 4.5% (Last 7 Days Cases 11,209; Last 7 Day Hospitalizations, 505)
4/1/21: H/c 3.9% (cases 10,988; Last 7 Day Hospitalizations 430)
3/25/21 H/c 4.6% (cases 8579; H 390)
3/18/21 H/c 4.4% (cases 6949; H 304)
3/11/21 H/c 3.9% (cases 6579; H 257)
3/4/21 H/c 4.8% (cases 5589; H 269)
2/25/21 H/c 4.9% (cases 5546; H 273)
GET THE PICTURE? Hospitalizations/case not going up. Let's do few more states with high variant prevalence
4/6/21 H/c 6.6% (cases 45192; H 3000)
4/1/21 H/c 6.0% (cases 39801; H 2379)
3/25/21 H/c 6.3% (cases 26,271; H 1653)
3/18/21 H/c 5.9% (cases 17,707; H 1039)
3/11/21 H/c 7.3% (cases 11810; H 859)
3/4/21 H/c 7.4% (cases 9492; H 706)
2/25/21 H/c 7.8% (cases 8,498; H 661)
Same true of FL (3,191 B117 cases sequenced) where hospitalization/case ratio has reduced from 8% on 2/25/21 to 6% this week. Same true of CO (894 B117 cases sequenced) where hospitalization/case ratio has decreased from 4% on 2/25/21 to 3% last week. Increased virulence not seen
3) And final concern- variants (B117) will evade our vaccines? Hope I addressed this yesterday (thread). So, here is a thread on why B117 or variants are not deterring progress with these amazing vaccines & should not signal lockdowns/school closures
@ThreadReader unroll
And to finish off this LONG thread - please read this article - "The course of the UK COVID 19 pandemic; no measurable impact of new variants". Variants had nothing to do with transmission or mortality. Phew, seems prudent for us to move on.
One other concern I have seen raised about B117 is whether it is causing more severe disease in the US among children. Fortunately, no evidence of increased hospitalizations among children over time in areas with B117 (like Michigan) from data: healthdata.gov/Community/COVI… Image
And here is the hospitalization data from Pennsylvania and Florida also showing no evidence of increased virulence over time of the virus (as B117 prevalence increases) in children ImageImage
And here is the data from Minnesota. So happy we have the ability (with publicly-available data) to test our concerns (e.g. B117 more virulent in children) and, thereby, relieve us of them. All of this data publicly available from HHS/ CDC, etc. Image
Good news. New papers today in Lancet journals showing B117 doesn't cause more severe disease. 1st in Lancet Public Health. Analysis covered 13 full weeks in England over the period when the proportion of B.1.1.7. grew most notably Sept 28-Dec 27, 2020
Traditional NPIs worked against B117. No statistically significant associations between proportion of B.1.1.7. within regions & the type/duration of symptoms people experienced, no more severity or hospitalizations. More transmissibility (Ro 1.35x with B117).
2nd paper here from Lancet ID between Nov 9 & Dec 20, 2020. Authors compared illness severity in people with and without B.1.1.7 & calculated viral load. No evidence of an association between the variant and increased disease severity (hospital, death.)
But also found higher viral loads in nasal swabs with B117 than non-B117 indicating likely higher transmissibility. So not more virulent (doesn't cause more severe disease), more transmissible, traditional non-pharmaceutical interventions work, crushed in England by vaccines.

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More from @MonicaGandhi9

21 Apr
Want to talk about INFLECTION POINT and how it looks like we have reached this in our country with hospitalizations at this vaccination rate & also turning the corner in Michigan. We discussed this first with Israel & I think "inflection point" with both hospitalizations & cases
will be different by country/state/region depending on degree of natural immunity there. This article in Nature from early on in the Israel roll-out: "You need to vaccinate much >1/3 of the population to really see a reduction in transmission", how much
more probably depends on 1) natural immunity (surges before (CA has 38% of its population exposed); 2) degree of lockdown as you are vaccinating (UK more; Israel less; places in US variable); 3) maybe even what vaccine (?India). Paper from Israel (Fig)
Read 15 tweets
20 Apr
This is true but I am VERY worried about India right now. My understanding is that vaccine capacity is not maximal because more raw materials are needed. India has called on the Biden Administration (ASlavitt) for help. Masks/distancing as much as possible in crowded conditions.
India has Covishield (AZ vaccine) + Covaxin (Bharat Pharm). I see from phase I/II trial of the Covaxin vaccine that cell-mediated responses were generated (although used IFN-gamma assay that Sputnik V used in their paper instead of direct measurement).
However, reason worried about Covaxin is that we have not seen phase 3 clinical trial results yet except in press release; would love to see peer reviewed publication (does anyone know status?). Covaxin is a whole inactivated viral vaccine like Sinovac
Read 7 tweets
20 Apr
Will we be able to achieve herd immunity and at what level vaccination? I believe we will but I don't know at what % vaccination though I suspect it could be 65-70%. Why?
1) Achieving herd immunity with a vaccine is dependent on its effectiveness; the mRNA vaccines are more
effective than we dared hope with 100% efficacy at 6 months per Pfizer data and amazing CDC breakthrough data showing (with ongoing cases), of 77 million fully vaccinated against COVID-19, ~5,800 infections (0.008%) – 0.005% symptomatic (29% asymptomatic)
2) Study from Israel shows children do not need to be vaccinated to massively reduce transmission in this group. Just vaccinating adults >16 years brings down infections among children substantially (every 20 point increase adults; halves in children)
Read 6 tweets
19 Apr
@DLeonhardt article today NYT illustrates what @drlucymcbride, I & so many others discussing: a fear of normal or even following simple March 8 CDC guidelines that vaccinated people can get together without masks/distancing due to irrational fear.
"Fortunately, [fear] also curable. The vaccines have nearly eliminated death, hospitalization and other serious Covid illness among people who [got] shots. .vaccines have also radically reduced chances that people contract even a mild version of Covid or can pass it on to others"
Even acclaimed experts like @ashishjha realized how "awesome" it was to meet friend for drink unmasked 2 months (!) after his last shot. My advice for society on this as MD who talks to patients about irrational fear all time?
1) Leaders like President Biden? Model behavior like
Read 7 tweets
19 Apr
Breakthrough infections by CDC. If we take out 29% of the 5814 who were asymptomatic, the rate of breakthrough infection is actually 0.00005 (or 0.005%). That is amazing! I took out asymptomatic infection because those actually show vax works: IgA in nose
limits replication & keeps viral load low so can't transmit (multiple articles below). For instance careful contact tracing of 39 breakthrough infections in Sonoma County last week showed no transmission!
And please remember that is vaccine effectiveness (how do they work in real world?) under "stress conditions": we still have high cases in some areas, variable mask wearing, people have to work, etc. So should see very little breakthrough (with symptoms) in places with low cases
Read 4 tweets
18 Apr
How is US doing? 44 states doing well. In HHS/CDC/ASPR Report, 6 States have almost 50% of Confirmed COVID-19 Admissions in the last 7 days; these states represent 26% of the U.S. Population (MI, NY, FL, PA, NJ, IL). Reason such a mix of caution/optimism on the news.
Most of this still in Michigan although they have now reached peak hospitalizations and are coming down. Less natural immunity, B117 (but not all explained by that, see thread yesterday), seasonality?, vax rate slow in some counties esp at first
NY, NJ, PA: didn't vaccinate seniors (in SNFs) as fast as other states. So remaining 44 states + DC + the territories (74% of pop), have hospitalization rate of 8.5 per 100K overall (much less than 20-40K of flu) and approaching 5/100K in article washingtonpost.com/outlook/2021/0…
Read 5 tweets

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