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Mahesh Shenai, MD
@mahesh_shenai
Neurosurgeon, data analyst. Read beyond the title/ abstract and constructively question. Posts are my personal opinions, not medical advice.Tweets are my own.
Joined August 2021
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4,236 Followers

Mahesh Shenai, MD’s Tweets

Mahesh Shenai, MD
@mahesh_shenai
Where is the data that supports bivalent efficacy against BA4/5? And if we don't have that data for BA4/5, how do we know it will work against XBB.1.5? Recommendations should be backed by data.
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Ashish K. Jha, MD, MPH
@AshishKJha46
The new bivalent shot is your best protection against both infection & serious illness Another question: How well do our tests work XBB.1.5? All the evidence says that they should work just fine And last but not least, how well do our treatments work? 6/n
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Mahesh Shenai, MD
@mahesh_shenai
Excellent thread, finding high C19 seroprevalence in <18yo, concluding strong natural protection against serious C19. Vax/booster recs should be stratified, not universal.
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Shamez Ladhani
@ShamezLadhani
1/ Our @ukhsa paper on paediatric #SARSCoV2 antibody prevalence in England is now published By Sep 2022, 97.2% of 1-17 year-olds had #SARSCoV2 antibodies Our findings are critical for future #COVID19 vaccine/booster recommendations for kids …🧵 👉sciencedirect.com/science/articl
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Mahesh Shenai, MD
@mahesh_shenai
🚩Quick takes on MMWR BV study re: ED/UC visits- - Relative VE (vs. prior MV doses) <50% unless > 8 months out. - rVE vs. hospitalization <50% - declined to stratify by age, prior inf, or comorbids (why?) - design precludes calc of absolute risk ⬇️
cdc.gov
Early Estimates of Bivalent mRNA Vaccine Effectiveness in...
This report describes the effectiveness of the updated (bivalent) COVID-19 vaccines for prevention of COVID-19 associated emergency department and urgent care visits and hospitalization among adults a
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Mahesh Shenai, MD
@mahesh_shenai
twitter.com/mahesh_shenai/ The exclusions are peculiar. -100 case pts that were flu+ -42 pts were flu "indeterminate" -71 with undetermined vax status Total exclusions approximate or exceed size of case and control groups!
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Mahesh Shenai, MD
@mahesh_shenai
Replying to @VPrasadMDMPH
They specifically excluded control (non C19 pts) that tested + for flu, because those person's were less likely to have received the flu vax, and therefore also the C19 BV vax. This effectively reduces the C19 unvaxxed proportion in the control group, elevating the VE.
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Mahesh Shenai, MD
@mahesh_shenai
🚩Quick takes on new MMWR: -Small study, limit to >65yo hosp. pts w/ symptoms. -32% excluded=large selec. bias - design precludes calc. of absolute benefit/NNV -each adjustment seems to favor +VE - probable benefit to >65yo, magnitude questionable
cdc.gov
Early Estimates of Bivalent mRNA Vaccine Effectiveness...
This report describes the effectiveness of the updated (bivalent) COVID-19 vaccines for prevention of COVID-19-associated hospitalization among adults ages 65 years or older who did not have a weakene
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Mahesh Shenai, MD
@mahesh_shenai
cdc.gov/mmwr/volumes/7 New CDC MMWR re Bivalent VE vs. hosp. in >65 yo pop.=73%. You would think after 3 mos. and MILLIONS of doses, CDC would give robust VEs for many scenarios. Instead, they manage only this study in a population of 798 hospitalized adults >65. Why?
cdc.gov
Early Estimates of Bivalent mRNA Vaccine Effectiveness...
This report describes the effectiveness of the updated (bivalent) COVID-19 vaccines for prevention of COVID-19-associated hospitalization among adults ages 65 years or older who did not have a weakene
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Mahesh Shenai, MD
@mahesh_shenai
5d/ The title of the paper is “APPARENT risks of postural orthostatic tachycardia ..." The authors seem to imply uncertainty in their own title! Which I believe is a respectable signal that they suggest the findings should be taken with a degree of caution.
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Mahesh Shenai, MD
@mahesh_shenai
5c/ A subtle finding of this study is that vax appears to be a greater risk factor than infxn (2.6 x vs. 1.5x) for myocarditis, but the small sample size of post-infectious myocarditis limits its significance. The risk appears to be much higher in males (~3.5) vs. females (~1.4).
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Mahesh Shenai, MD
@mahesh_shenai
5a/ Some further discussion: The authors are very careful to limit their conclusion THAT VAX MAY LEAD TO POTS, by emphasizing the 5.35x finding in their conclusion. Of course, the authors themselves LIMITED that conclusion, both comparison groups are inherently different.
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Mahesh Shenai, MD
@mahesh_shenai
4i/ So, -all data limited by ICD accuracy/omission. - the reported 5.35x (infxn:vax) is signif limited by probable selection bias. -the modest 1.10x (post:pre POTS:CPCs) number does not overcome ICD inaccuracies. -The 1.08x (Post:pre infxn POTs:CPCs) was never significant.
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Mahesh Shenai, MD
@mahesh_shenai
4g/ Authors acknowledge this selection bias, and state “these populations may have inherent differences,the comparisons between populations should be interpreted more cautiously than [within] populations. So the most dramatic result (5.35x) is not as reliable as 1.10x for vax.
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Mahesh Shenai, MD
@mahesh_shenai
4f/ There may also be selection bias. Look@ Tables 1,2: POTS diagnosis BEFORE vax was 176/100k, whereas BEFORE infxn 987/100k. That is 5.6x difference. In fact, there are many dx that seem unbalanced between the two groups, when one expects pre-exposure groups to be similar.
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Mahesh Shenai, MD
@mahesh_shenai
4e/ The auths fairly recognize this “non-differential” misclassification bias, stating bias towards the “null” (e.g. understate the rate). This may be true in the absolute rates, but if there is selective bias in the denominators (pre-exposure), the odds may be exaggerated.
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Mahesh Shenai, MD
@mahesh_shenai
4d/ But, there is another problem here – during the time of study ('20-'22), no POTS specific ICD code existed. Surrogate codes (I49.8 & G90.9) were thus used. The auths. then had to internally validate this method using a small subset of 50 pts, and found an accuracy of 80%.
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Mahesh Shenai, MD
@mahesh_shenai
4b/ They calculate the ODDS of POTS diagnoses, myocarditis, and then other common primary care dx (CPCs), comparing pre- and post- exposure rates. Dx categories are determined by ICD-9/10 codes from admin DBs, which can be messy. This can lead to misclassification biases.
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Mahesh Shenai, MD
@mahesh_shenai
4a/ METHODS: The auths set up 2 separate retrospective cohorts @ Cedars-Sinai in LA, [1] vax (with infxn excluded) and the [2] infection (with vax excluded). They then used ICD codes to calculate the frequencies of diagnoses before and after each exposure (per 100k).
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Mahesh Shenai, MD
@mahesh_shenai
3b/If that doesn’t function correctly, the heart must beat excessively fast (tachycardia) to compensate. It is a condition that was recognized long before COVID-19, and is not unique to it at all. Generally, the cause of POTS is diverse and often unknown in many cases.
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Mahesh Shenai, MD
@mahesh_shenai
3a/ A brief primer on “POTS” = “postural orthostatic tachycardia syndrome”. When you go from a lying 2 standing, gravity pulls blood to feet and AWAY from your brain. Our bodies have adapted to counter that drop, and maintain BP to brain via the “sympathetic” nervous system.
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Mahesh Shenai, MD
@mahesh_shenai
2c/ This is somehow being narrated into support for “long-COVID”,eg: twitter.com/BerkeleyJr/sta Instead, at most, it CAUTIOUSLY reports that POTS dx are 🔼 after vax, but at a rate 5x 🔽 than infxn, but almost no differently than diagnoses of other common conditions post-exposure.
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Berkeley Lovelace Jr.
@BerkeleyJr
New research confirmed a link between a Covid infection and a debilitating heart condition called POTS, or postural orthostatic tachycardia syndrome, that has been diagnosed in some patients with long Covid. nbcnews.com/health/health-
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Mahesh Shenai, MD
@mahesh_shenai
2b/ The study uses ICD 9 and 10 codes to identify various diagnoses. Study is subject to misclassification and selection bias, as noted by the authors. As shown below, the promoted 5.35x “topline” result is much less valid than modest OR suggesting vax causes POTS (1.10x)
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Mahesh Shenai, MD
@mahesh_shenai
sensiblemed.substack.com/p/how-myocardi Excellent essay by
@drjohnm
, a cardiologist, re: asymmetric & unknown risks of myocarditis. Myocarditis cannot be dismissed, especially by leaders of orgs enforcing mandates, esp w/ young, healthy constituents. Risk/benefit depends on the individual.
sensiblemed.substack.com
How Myocarditis Influences Vaccine Mandate Decisions
Monday is usually the Study of the Week. This week I argue that SARS-CoV-2 vaccine mandates are wrong.
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Mahesh Shenai, MD
@mahesh_shenai
🚩 Interesting "Viewpoint" by FDAs Dr.Marks, re: future C19 vax develop.: - vax has beneficial AND "unanticipated consequences" - immunobridging unreliable - RCTs needed But then, why did his FDA/VRBPAC approve bivalent boosters for all, w/o RCTs?
jamanetwork.com
Urgent Need for Next-Generation COVID-19 Vaccines
This Viewpoint argues that the development of a distinctly improved generation of SARS-CoV-2 vaccines is paramount to offering a greater breadth and depth of protection for a longer duration against...
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Mahesh Shenai, MD
@mahesh_shenai
youtu.be/NOeDCdWH09o?t= Re: #TwitterFiles2 & dissenters, see this recent Califf/Fauci exchange: (12:38) Califf: "we've got EFFORTS to respond to this...its designed to disrupt & undermine the ability and credibility of govt" (14:15) Fauci:"I'm wondering if they have day jobs."
youtube.com
FDA Virtual Employee Town Hall
FDA Commissioner Robert Califf, Principal Deputy Commissioner Janet Woodcock, Deputy Commissioner for Operations and Chief Operating Officer Jim Sigg, and As...
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