COVID19 mini-update, April 11, 2021: clues about rare Oxford/Astrazeneca thrombotic events; Israel “has reached a form of herd immunity”; Pfizer and South African variant

(1) Scientists conclude that in a very small number of people dosed with the Oxford/AstraZeneca viral vector vaccine, administration triggers an autoimmune reaction to Platelet Factor 4,

with results similar to a known complication of anticoagulation therapy with heparins, heparin-induced thrombocytopenia.

The original papers, by two independent teams, appeared in the New England Journal of Medicine:

https://doi.org/10.1056/NEJMoa2104840 and https://doi.org/10.1056/NEJMoa2104882

A popular, but very detailed, writeup can be found here (via Insty).

(2) Prof. Eran Segal of Weizmann declares Israel “has reached a form of herd immunity“.

Israel may have reached “a sort of herd immunity” and can safely ease further restrictions, a top expert said Saturday.

With over 4.9 million Israelis fully vaccinated, the number of daily coronavirus cases has plummeted by 97 percent, Eran Segal, a computational biologist at the Weizmann Institute of Science, told Channel 12.

To be clear, Israel exclusively used the Pfizer mRNA vaccine (plus a little bit of its “fraternal twin” Moderna, which is somewhat less demanding in terms of cold supply chains). This was the first time ever that messenger RNA vaccines have been used in a large-scale setting, and they have surpassed expectations. This is likely to have a lasting impact on biotech, two different sources told me.

(3) Also in Israel, a team found indications that the South African mutation (which accounts for about 1% of COVID19 cases in Israel) may be able to ‘escape’ the Pfizer jab to some degree. However, it does not spread as easily as the British variant (over 90% of Israeli COVID19 cases), against which Pfizer clearly is as effective as against what biologists call the wild type (the original, unmutated virus, a.k.a., ‘classic COVID’).

The Times of Israel has a popular write-up; the preprint in MedRXiv can be found at https://doi.org/10.1101/2021.04.06.21254882

3 thoughts on “COVID19 mini-update, April 11, 2021: clues about rare Oxford/Astrazeneca thrombotic events; Israel “has reached a form of herd immunity”; Pfizer and South African variant

  1. I have read that Astrazeneca and Johnson&Johnson have partnered.
    Is today’s J&J vaccine “pause” pretty much the same as the AZ “thrombotic events”? Because the headlines I’ve seen talk about women who have had blog clots from J&J.

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