4. Serious and fatal adverse reactions have been reported
Both serious adverse effects and vaccine-related deaths have been reported in the UK , the US , and Europe .
Many of these did not occur during the trials, such as blood clots  (now known as vaccine-induced immune thrombotic thrombocytopenia or VITT), which have been seen specifically in young adults.   We are seeing increasing reports of Myocarditis after vaccination, particularly in young men.  
In the US, several children under the age of 18 have been reported to have died after a Covid-19 vaccine. 
Critics of the reporting systems for vaccine adverse events (such as the Yellow Card system in the UK and VAERS in the US) often point out that anyone can report a side-effect. Without further investigation, we can’t be sure that the condition is a result of the vaccine. This is true, and ideally there would be a more reliable process to capture all side effects. There isn’t however, and this is a real problem – we just don’t have accurate systems in place.
We can be fairly certain, however, that adverse events are under rather than over-reported. A 2010 federal study performed by Harvard consultants on behalf of the Agency for Healthcare Research and Quality (AHRQ) found that fewer than 1% of all vaccine-related injuries are reported to VAERS in the US.  In the UK, our Government estimates that the Yellow Card system captures fewer than 10% of adverse drug reactions. 
Adverse reactions to the vaccines are being reported to Government monitoring schemes (such as UK Yellow Card and US VAERS) at a much higher rate than is usual with vaccines (see graph below).
MHRA Adverse Drug Reaction (ADR) reports for all vaccines in the last 10 years (as of Aug 2021)
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It’s safer to wait