What modifications have been made to existing Covid-19 vaccine products; for what reasons were those modifications made; and when those modifications were approved by the Medicines and Healthcare Products Regulatory Agency.
The Medicines and Health products Regulatory Agency may authorise a line extension, which is a new product authorisation linked to the original marketing authorisation. Various versions of the COVID-19 vaccines have been approved as line extensions to the original vaccines since the first COVID-19 vaccines were approved in December 2020. Variations may be requested to add an indication, dosage form, strength or pack size, which will make the vaccine available for a wider patient pool, whilst maintaining effectiveness and an acceptable safety level. For example, Pfizer, in late 2021, made an application to extend the indication of their vaccines to children between five and 11 years old in a smaller 10 micrograms per dose, and later, via the European Commission Decision Reliance Procedure, a new three micrograms per dose in infants and children between aged six months and four years old. New versions of the vaccine have also been introduced to adapt the vaccines to the new strains of the virus.