10 April 2021 Episode 128 Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT) allergy and vaccine mixing

Sat, 04/10/2021 - 22:31

 

Dear colleagues,

 

Astra- Zenece thrombotic/throimbopenic incidents

 

Ep 128-0: is a Nature journalist paper on the thrombosis-and-thrombocytopena seen after AZ vaccine.   By 22 March, the EMA had assembled 86 reports of people who had experienced blood clots in the brain or abdomen within two weeks of receiving a dose of the Oxford–AstraZeneca vaccine.

 

Ep 128-1 is the official NEJM paper b y Greinacher on the 11 German and Austrian patients and Ep 128-2 is a back-to-back NEJM paper bij Schults on  5 Norvegian patients.  Strikingly:

  • 13 out of 16 are women all in the 22-54 yrs age range, most without precedents.  
  • Very often crebral or splanchnic hemorgahhes or thrombosis with 9 fatalities
  • Antibodies to platelet factor 4 with platelt activating properties were present
  • Precise mechanism unknown
  • Treatment: heparin cautiously, immunoglmobulins, platelets, corticoids….?

 

There is a tentative name now:  vaccine-induced immune thrombotic thrombocytopenia (VITT). 

 

Ep 128-3 provides very practical guidelines on diagnosis and treatment of this syndrome. Clearly, these authors stress as a first point: positive effects of vaccination with the AstraZeneca COVID-19 vaccine outweigh the negative effects.  

 

Ep 128-4 is a calculation of potential risk of this complicatoion versus benefit of not being admitted to ICU,  according to age and level of exposure.  Clearly, even at low exposure, the benefit already outweigh the risk from 30 years on….

 

Anafylactic reactions:

 

Ep 128-5 refers to a EMA report that also Astra-Zeneca can lead to serious allergic reactions (46 cases in 5 million).

 

The NHS in UK has developed guidelines:

 

https://www.sps.nhs.uk/articles/advising-individuals-with-allergies-on-their-suitability-for-pfizer-biontech-covid-19-vaccine/

 

https://www.sps.nhs.uk/articles/advising-individuals-with-allergies-on-their-suitability-for-moderna-covid-19-vaccine/

 

https://www.sps.nhs.uk/articles/advising-individuals-with-allergies-on-their-suitability-for-astrazeneca-covid-19-vaccine/

 

 

Heterologous prime-boost or “mixing vaccines”

 

Ep 128-6: A Chinese study, where various combinations of (Chinese) inactivated SARS-CoV-2, recombinant receptor-binding domain (RBD), Adeno-5 vector and mRNA are compared in mice. It is evident that many heterologous vaccination schemes are superior to homologous ones.  Notably, Adeno-5, followed by mRNA results in higher neutralization titers than 2 X RNA. Clearly, these results are in line with many previous observations in experimental vaccination, but these are Chinese vaccines in mice….  

 

Ep 128-7: In Oxford a trial with 800 older volunteers is ongoing to compare homologous AZ or Pfizer with heterologous schemes (also different intervals).  The results, however, are expected after one year.

 

Ep 128-8:  As could be expected, there are already voices in various countries to start mixing. Uncontrolled experiments….

 

Ep 128-9:  CDC recommendations on 2 April for fully vaccinated people: still a lot a caution.  The evidence of strong protection against infection and onwards transmission is still limited to Pfizer, but for that vaccine it is very good or excellent!

 

Ep 128-10 and 11: the CDC is recognizing that the risk of SARS-CoV-2 transmission via contaminated surfaces is minimal in practice.

 

Best wishes,

 

Guido