COVID vaccine & Blood clots update: The European Medicines Agency @EMA_News has concluded that unusual blood clots with J&J vaccine are a very rare side effect.

The clots are very very rare (8 cases out of 7 million vaccinated in the US). ema.europa.eu/en/news/covid-…
The blood clots with J&J vaccine resemble clots seen with the Astra Zeneca vaccine. Both these vaccines are adenoviral vector based vaccines.

These unusual clots are:
-Very rare
-Cerebral venous or splanchnic
-Associated with low platelets
-Have high PF4 antibodies
The risk estimates of these clots overall varies because we don't have full capture of numerator and denominator. What we know suggests risk:

~1 in 1 million with J&J
~1 in 250,000 with Astra Zeneca based on UK estimates
~1 in 100,000 with Astra Zeneca based on EU estimates.
Note that cerebral venous thrombosis has a baseline rate of about 1 in 250,000 even without the vaccine. COVID itself causes cerebral venous thrombosis at a much higher rate.

The benefits of J&J vaccine and Astra Zeneca vaccine far outweigh the risks in everyone over age 30.
The temporal relationship to the vaccine and the unusual combination of cerebral venous (Or splanchnic venous) thrombosis along with very low platelets is what causes the concern for a real link to the vaccine.

These clots resemble ones we sometimes see after use of heparin.
We now have an idea of the mechanism. We will be able to diagnose these clots sooner, and manage them better. So I think outcomes will improve significantly if and when these very rare clots do occur.
I strongly urge people to get whichever vaccine you are offered. All are highly effective. COVID is 100 times worse than any side effect of the vaccine.

If you are less than 30, discuss with your doctor, unless such decisions have been made already at the national level.
For more details on the mechanism by which these clots occur see thread below.
There is no risk of these unusual clots with mRNA vaccines, either Pfizer or Moderna.

Clearly after 120 million people have been vaccinated in the US with those two vaccines, we have a good idea of how incredibly safe they are.
Some people ask why didn't we catch the risk of the clots with the randomized trials.

Given the rarity of these clots, we would have needed randomized trials of a million people to find such ultra rare events. So unfortunately these type of events are only detected post-approval

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Vincent Rajkumar

Vincent Rajkumar Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @VincentRK

20 Apr
A high viral dose exposure, a bad mutant variant, or an immune system compromised by prior illness or chemotherapy — are 3 potential reasons why COVID reinfection or post-vaccine infection may occur.
Lowering viral dose exposure can be achieved by masks, distancing, ventilation. I think it's a good idea to follow these measures until the pandemic is under control in your country, even if you have had prior COVID and are vaccinated. Helps you. And helps reduce spread to others
Immune system thats compromised by prior illness or chemotherapy can be helped by ongoing research on vaccine boosters. As well as improved treatments. But note that no matter how immunosuppressed, whatever protection we get from vaccines is definitely better than nothing.
Read 4 tweets
20 Apr
COVID What works:

Masks
Distancing
Ventilation
Vaccines
Dexamethasone
Convalescent plasma
Remdesivir

& Importantly for high risk groups:

MONOCLONAL ANTIBODIES
Bamlanivimab/Etesevimab
(Eli Lilly)
Casirivimab/imdevimab
(Regeneron)
phe.gov/emergency/even…
Note that FDA EUA for use of Bamlanivimab alone has been revoked.

Bamlanivimab plus etesevimab given in combination is authorized by FDA EUA. fda.gov/media/145808/d…
Regen-COV (casirivimab and imdevimab) is also available under EUA. fda.gov/media/145611/d…
Read 4 tweets
19 Apr
COVID mortality by age group & implications for Astra Zeneca, J&J vaccines:

1/ The chances of dying if you get COVID infection (IFR) is ~0.5% (USA). Varies by country.

2/ In EVERY COUNTRY risk varies dramatically by age.

Age 50-64-->10 times higher risk of death than 30-39. 👇 Image
3/ The estimated risk of dying from COVID infection (infection fatality rate; IFR) is:
~1 in 400 for age 45-54,
~1 in 125 for age 55-64, and
~1 in 40 for age 65-74.
link.springer.com/content/pdf/10… Image
4/ The numbers in the table are for all COVID infections, with and without symptoms. The risk of dying from COVID is 3-4 times higher if you have confirmed Symptomatic COVID. This is not the flu.
Read 9 tweets
17 Apr
1/The COVID virus doesn't know political borders or geography.

Countries which controlled the pandemic from the outset made 1) the politically & economically hard decision of closing borders except through quarantined entry, and 2) test/trace/isolate within.
2/ Depending on how many cases were already inside, some countries had to also implement universal masking and distancing. Countries which managed to seal borders before significant amount of cases got inside the country could get away with limited masks and distancing measures.
3/ Countries where COVID could not be controlled in time unfortunately ended up with large numbers of affected people. Masks & distancing are needed to limit spread & save lives until a definitive solution could be implemented. We have a highly promising solution now: Vaccines.
Read 8 tweets
15 Apr
Did COVID cause remission of an advanced cancer?

61 year old man was diagnosed with Hodgkin Lymphoma. He then developed COVID. Only got supportive care. No steroids or immunotherapy. 4 months later, cancer had mostly resolved (left image vs right) 🪢

onlinelibrary.wiley.com/doi/full/10.11…
There are 3 possible explanations:

1) Hodgkin Lymphoma is unique among cancers in that what you see as big lumps of tumor are not cancer cells: Bulk of tumor mass is just normal reactive lymphocytes with small amounts of cancer (Reed Sternberg) cells mixed in. (Owl like cells)
So after COVID the reactive cells may disappear due to the severe viral infection, making it look like the cancer has gone into remission. But maybe only the normal reactive cells have disappeared. Time will tell if the true Hodgkin cancer cells are still there and will come back
Read 7 tweets
14 Apr
Low platelets: common
Blood clots in legs/arms: common

Blood clots in veins draining the brain: very rare
Blood clots in veins draining the brain plus very low platelets: extremely rare

Early on, Astra Zeneca: puzzle
Now: J& J. Hence the pause.

Pfizer/Moderna: No such clots
The risk is very small.
6 cases after 7 million doses of J&J vaccine. But just need few days to verify numerator, and assess risk/benefit.

Risk from COVID likely far outweighs risk from Astra Zeneca or J&J vaccine greatly in almost all people >age 30.
We have 2 other safe vaccines, Pfizer and Moderna in the US: After 180 million doses given no concern for such blood clots related to the vaccines.

Vaccine administration sites are adjusting. We have enough vaccines for everyone.

Things will be clearer in a week.
Read 4 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!