Monica Gandhi MD, MPH Profile picture
Apr 7, 2021 22 tweets 7 min read Read on X
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
pfizer.com/news/press-rel…
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)
abcnews.go.com/amp/Health/wir…
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
MICHIGAN:
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
threadreaderapp.com/thread/1379294…
@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.
medrxiv.org/content/10.110…
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
thelancet.com/journals/lanpu…
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.)
thelancet.com/journals/lanin…
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

Aug 30, 2023
HOW LONG DOES IMMUNITY LAST? To COVID vaccines or infection? We do not really know but there have been some really nice papers lately that give us more information. Please remember immunity divided into antibodies (which can come down & not work as well against variants)
IgA is one in the nose & mouth ("mucosa") that is raised by shots (vaccines) to certain extent but rise higher after natural infection; IgG is the one that is "humoral" or in the bloodstream. Many threads on here about cellular-mediated immunity: B & T cells cover all variants
This recent preprint is really important and summarized by @florian_krammer below in depth. Main take-aways: Breakthrough infections induce IgA (we knew) but protection from vaccine long-lasting even against former variants to severe disease/mortality
Read 8 tweets
May 3, 2023
RSV VACCINE FOR OLDER ADULTS: Respiratory syncytial virus (RSV) respiratory virus (most common after flu pre-COVID). 2 subtypes, A&B (1 dominates/season). Droplet; Recurrent infections. Most severe in neonates & adults >65; FDA approves 1st RSV vax today
msn.com/en-us/news/us/…
RSV vaccine 3 trials of new RSV vaccine, all published in the @NEJM recently so just to keep them straight- here is the vaccine which just got approved May 3 by the FDA for older adults. Remember our T/B cells so protection against severe disease higher!
nejm.org/doi/full/10.10…
A single dose of the RSVPreF3 OA vaccine had an acceptable safety profile and prevented RSV-related severe respiratory illness by 94% in adults>=60 years (71% against RSV infection, likely to fall with time as antibodies fall but severe disease protection will remain)
Read 4 tweets
Mar 21, 2023
NASAL VACCINES: To explain nasal vaccines, we have to explain the immune system first.
IgA is an antibody that helps attack the pathogen and exists in mucosal surfaces (like nose/mouth)
IgG is an antibody that is in the bloodstream
bbc.com/news/world-asi…
Cellular immunity is fantastic, redundant (so even if one cell line down in immunocompromised, have other), generated by either vaccine or infection; Comprised of
T cells- so in breadth from vax - works even across spike protein with its mutations
And the 2nd type of cell produced by vaccines or infection -B cell- amazing thing about B cells is that - if see omicron or one of its subvariants in future- they make antibodies adapted to that variant or subvariant (aided by T cells); adaptive immunity
Read 15 tweets
Mar 15, 2023
PUBLIC HEALTH POLICY: Seem to be at reckoning phase of COVID response- what worked, what didn't. Which interventions will be used in future pandemic responses? Interventions asked of public need good medical evidence for them (e.g. RCTs preferably, systematic reviews) to impose
In our field, Cochrane reviews represent best way to sum up the medical evidence to date by performing meta-analyses or systemic reviews of currently-available data; here is Cochrane on masks & other interventions for respiratory viruses including COVID
cochranelibrary.com/cdsr/doi/10.10…
Many asked past 3 years how CDC developed policies on masks (& age to mask), distancing (feet), ventilation, schools-> all non-pharmaceutical interventions. Originally theory-based. Now 3 years in, have data (RCTs highest level) to form policies from both US and other countries
Read 4 tweets
Mar 6, 2023
VACCINE DISCRIMINATION: We need to stop vaccine requirements for US entry like almost every other country. Am finishing COVID chapter for our ID "bible" & vaccines prevented transmission early on with alpha, but not enough now with current variants to justify such discrimination
Moreover, shame, stigma, blame (remember COVIDiots?), coercion, discrimination not good public health tools. When used for HIV, public health & ID physicians decried them but tactics used a lot in COVID. This book tries to explore & correct that for future
barnesandnoble.com/w/endemic-moni…
Concept of #harmreduction in pandemic responses means watching carefully if vulnerable people (like students, older people, low-income populations, migrants, sex workers, prisoners, those with disabilities, refugees, minorities) harmed more by response
nature.com/articles/s4146…
Read 4 tweets
Feb 8, 2023
FEAR: Some media & public health officials concerned Americans aren't fearful of COVID now. But the vaccines & therapeutics DO WORK. If we can't celebrate biomedical advances & imbibe their effectiveness (we have better tools for COVID than flu), what is point of developing?
In HIV medicine, when therapies came out, we didn't say to people- stay fearful; make this the controlling principle of your life. The book #Endemic I wrote (coming out July 11, 2023) hails these biomedical advances & the age we are in to fight pandemics to reassure the world
This is a rather brilliant summary of the issue from @benryanwriter
Read 4 tweets

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