[LINK] Accidental intravenous injection of AstraZenica as potential mechanism for post-vaccination TTS.

[Marghanita da Cruz]

> As of 3 June 2021, WHO has evaluated that the following vaccines 
> against COVID-19 have met the necessary criteria for safety and efficacy:
>
>   * AstraZeneca/Oxford vaccine
>     <https://www.who.int/news-room/feature-stories/detail/the-oxford-astrazeneca-covid-19-vaccine-what-you-need-to-know>
>
>   * Johnson and Johnson
>     <https://www.who.int/news-room/feature-stories/detail/the-j-j-covid-19-vaccine-what-you-need-to-know>
>   * Moderna
>     <https://www.who.int/news-room/feature-stories/detail/the-moderna-covid-19-mrna-1273-vaccine-what-you-need-to-know>
>
>   * Pfizer/BionTech
>     <https://www.who.int/news-room/feature-stories/detail/who-can-take-the-pfizer-biontech-covid-19--vaccine>
>   * Sinopharm
>     <https://www.who.int/news-room/feature-stories/detail/the-sinopharm-covid-19-vaccine-what-you-need-to-know>
>   * Sinovac
>     <https://www.who.int/news-room/feature-stories/detail/the-sinovac-covid-19-vaccine-what-you-need-to-know>
>
>
> Read our Q&A 
> <https://www.who.int/news-room/q-a-detail/coronavirus-disease-use-of-emergency-use-listing-procedure-forvaccines-against-covid-19> 
> on the Emergency Use Listing process to find out more about how WHO 
> assesses the quality, safety and efficacy of COVID-19 vaccines.

https://www.who.int/emergencies/diseases/novel-coronavirus-2019/covid-19-vaccines/advice

On 5/7/21 11:05 am, Kim Holburn wrote:
> https://www.biorxiv.org/content/10.1101/2021.06.29.450356v1.abstract
>
> Thrombocytopenia and splenic platelet directed immune responses after 
> intravenous ChAdOx1 nCov-19 administration.
>
>> Vaccines against SARS-CoV-2 are based on a range of novel vaccine 
>> platforms, with adenovirus-based approaches (like ChAdOx1 nCov-19) 
>> being one of them. Recently a rare and novel complication of 
>> SARS-CoV-2 targeted adenovirus vaccines has emerged: thrombosis with 
>> thrombocytopenia syndrome (TTS). TTS is characterized by low platelet 
>> counts, clot formation at unusual anatomic sites and 
>> platelet-activating PF4-polyanion antibodies reminiscent of 
>> heparin-induced thrombocytopenia. Here, we employ /in vitro/ and /in 
>> vivo/ models to characterize the possible mechanisms of this 
>> platelet-targeted autoimmunity. We show that intravenous but not 
>> intramuscular injection of ChAdOx1 nCov-19 triggers 
>> platelet-adenovirus aggregate formation and platelet activation. 
>> After intravenous injection, these aggregates are phagocytosed by 
>> macrophages in the spleen and platelet remnants are found in the 
>> marginal zone and follicles. This is followed by a pronounced B-cell 
>> response with the emergence of circulating antibodies binding to 
>> platelets. Our work contributes to the understanding of TTS and 
>> highlights accidental intravenous injection as potential mechanism 
>> for post-vaccination TTS. Hence, safe intramuscular injection, with 
>> aspiration prior to injection, could be a potential preventive 
>> measure when administering adenovirus-based vaccines.
>
-- 
Marghanita da Cruz
Telephone: 0414-869202
Email:  marghanita at ramin.com.au
Website: http://ramin.com.au