I’m not an expert but it is usually between 5-10 years Vaccine Research & Development - Johns Hopkins Coronavirus Resource Center (jhu.edu).
The MHRA was still operating under the European Medicines Agency (EU) in 2020 and issued a TUA. The mRNA vaccine was different to previous vaccines in that it used gene therapy and was a new technology. Gene therapies are usually classed as ‘advanced medicines’ and have to comply with more regulations.
Legal framework: Advanced therapies | European Medicines Agency (europa.eu)
However, ‘vaccines against infectious diseases’ are not classed as gene therapies under EU law: Commission Directive 2009/120/EC of 14 September 2009 amending Directive 2001/83/EC of the European Parliament and of the Council on the Community code relating to medicinal products for human use as regards advanced therapy medicinal productsText with EEA relevance (europa.eu)
So, inadvertently it created a loophole through which mRNA products could be marketed as vaccines.
The WHO called covid-19 a Public Health Emergency of International Concern (PHEIC) on March 11th allowing for vaccinations to be developed on an emergency use basis if none previously existed.
So my concern is that a new technology that only recently began trials was given a ‘TUA’ and would normally require years of trials and testing to be certified as safe.
