Why the change in time between vaccines (6 weeks to 4 months)?Updated: April 21st, 2021
“Many feel concerned/worried that the efficacy will be less as more time passes. What informed this change in timeline, and how did this conclusion get reached?”
The UK chose to extend the delivery of the second dose to people to prioritize getting first vaccine doses to more people and reduce hospitalizations. The new medical advice as shared by the NHS (National Health Service) is that the second dose of the vaccine remains effective when given up to 12 weeks after the first dose and should be given towards the end of this 12 week period.