All COVID-19 vaccines that have received WHO Emergency Use Listing approval and/or stringent regulatory agencies’ emergency authorization have fulfilled all regulatory approvals and standards. The WHO Strategic Advisory Group of Experts (SAGE) has issued recommendations on the use of several vaccines, and continuously reviews evidence on new products. Some national regulators have also assessed other COVID-19 vaccine products for use in their countries.
Slight differences on age upper and lower limits, characteristics and properties of the type of vaccine used (for example mRNA, vector, protein based, live attenuated) and individual comorbidities (such as polysorbate allergic reactions or immunocompromised individuals) and conditions (for example pregnancy) can lean the scale towards one type or other. Therefore, in very particular cases, a risk-assessment and clinical evaluation may need to be performed to determine the most suitable vaccine for specific vaccines.
Consult with a healthcare professional for further questions and personal advice.