Actually it depends on individuals. My first 2 was Pfizer and booster was Moderna. I felt that Moderna’s jab was totally painless. For Pfizer I could feel the pressure of the needle. It’s probably just me, so I’m not really sure about others. https://www.todayonline.com/singapore/explainer-whats-best-mix-covid-19-vaccines-and-boosters-early-indications-and-studies-may
I took moderna for all 3 jabs. Surprisingly, the side effects for the booster jab wasn’t as bad the first two that I took. Just sore arms and a slight headache that was manageable without the use of Panadol. Took the booster at 27 weeks.