*@lightand no drug or vaccine is ever completely safe.
But after something has been used in thousands and thousands of ordinary people (including those that would not be allowed to take part in trials for various reasons) sometimes rare side effects are discovered that could not be expected to be found in a clinical trial of 10,000 people.
Think about it - if a side effect occurs in 1 in 10,000 people, or only in people with a rare pre existing condition, it's unlikely to come up in a trial of 10,000 people.
In most cases however these rare side effects don't actually mean the product is taken off the market - just that the side effect is added to the packaging, or they stop using the product for certain groups of patient.
In the case of a vaccine it's actually unlikely to have any long term effects as it is designed to cause a quick reaction in your immune system. There have been cases where a rare short term effect came to light after licensing. Rotavirus vaccine in children was linked to intussception after it went into general use. I can't remember if that was a genuine link but it the vaccine was withdrawn for a time whilst it was investigated. There are other products that are very widely used and actually have some pretty serious long term side effects, and people still use them. The contraceptive pill is an obvious example. There's a reasonable risk of thromboembolism if it's taken by overweight women, smokers or those over 30. Yet many of these women are still prescribed it
Ibuprofen is another one that is widely taken and is far riskier than any vaccine*
Thank you. It is probably going to end up being about any possible serious long term effects from covid vaccines.