EXPERT REACTION: Second Australian death from blood clots following AstraZeneca COVID-19 vaccine

The 48 reported Australian cases of thrombosis and thrombocytopenia syndrome (TTS) following administration of the AstraZeneca vaccine for COVID-19 must be kept in perspective.

The association between the vaccine and the risk of developing an adverse event afterwards continues to have been made without consideration and examination of an individuals’ own personal level of risk.
 
The continual reminders and reinforcement of these events only fuels fear of vaccination and hesitancy which is against the public interest.

Reported cases of these adverse events following administration of the AstraZeneca vaccine have automatically been assumed to be a result of the vaccine rather than a case by case evaluation of risk factors that may have increased the likeliness of TTS occurring in an individual.
 
Individuals should consult their general practitioner to evaluate their personal risk of developing TTS or any other adverse effect prior to vaccination.
 
This includes:

• Looking at all personal and family history for autoimmune disease or potential to develop TTS
• Evaluating currently prescribed or over the counter medications that may influence clotting processes and particularly where these may be associated with increased risk of TTS
• Discussing the risk of any upcoming or recent surgical procedures and treatments that increase the risk of thrombosis
• Getting a full blood count (if required) to evaluate risks
• Factoring in other risk factors such as smoking, use of oral contraceptives, HRT or use of hormones that stimulate red blood formation

Based on this information, a doctor will be able to assess the specific risk for an individual and advise if the AstraZeneca vaccine is suitable or if another COVID-19 vaccine formulation would be more advantageous.

People should fear the consequences of COVID-19 infection, not the vaccine to prevent this from happening.

I think vaccination remains the most effective strategy against the spread of SARS-CoV-2 virus and prevention of COVID-19 related hospitalisations in the community.  

Obviously, whether to vaccinate against the SARS-CoV-2 infection remains a personal choice.  

Similarly, risk-assessment of the AstraZeneca vaccine can also be subjective.  Despite these arguments, however, the age-specific benefit-to-risk balance of protection against viral infection and developing "thrombosis with thrombocytopenia syndrome" (TTS), also referred to as "vaccine induced immune thrombotic thrombocytopenia" (VITT), has been clearly demonstrated in a UK analysis. 

The UK data suggested the benefits of vaccination outweigh any potential complications. It has been reported the timing of greatest risk is between days 4-30 post-vaccination and people should seek medical attention if they are unwell post-vaccination.

Research is currently focused on a population of elevated antibodies against platelet antigens (PF4 and complexes), as well as the subsequent functional consequence(s) of these factors in causing VITT.