Belgian here, used to work for big pharma. The current procedures for clinical trials (very long, very expensive) were put in place after Thalidomide (google it

Belgian here, used to work for big pharma. The current procedures for clinical trials (very long, very expensive) were put in place after Thalidomide (google it). Pharma companies are terrified of this happening again, especially in a situation like this one where all eyes are on them. They follow FDA / EMEA rules to the letter and cutting corners is something nobody wants to do. I'd say those "shocked experts" aren't really experts at all. Some side effects simply can't be manifested during clinical trials since it will only occur once every 50 - 100.000 patients. If you test your vaccine on 5000 people and then proceed to vaccinate 4 million, there's a remote possibility that some of those (or worse, their offspring) will suffer serious side effects and it's totally normal they don't want to be held on the line for that simply because they had to hurry up. In the world of software development we know that having to hurry up never leads to anything good, now imagine there's a pandemic, people's lives are at stake and you're to be held liable for possible bugs - no thanks. (Anecdote: Pharmacovigilance is the practise of monitoring a drug basically forever. Quite recently it was discovered that domperidone (an OTC drug against nausea) led to an increased chance of serious heart problems and it lost its OTC status. This was after several decades of widespread use.)