A group from University of Pennsylvania Perelman School of Medicine has reported longitudinal analysis results of IgG levels and memory B cells following Pfizer (BNT162b2)/Moderna (mRNA-1273) vaccination.
- Vaccination boosts antibody levels for both SARS-CoV-2 recovered people and SARS-CoV-2 inexperienced people
- but, no additional boosting is observed after the second vaccine dose for SARS-CoV-2 recovered people
- Memory B cell responses continue to improve after the second dose for SARS-CoV-2 inexperienced people
- All ages benefit from vaccination, but vaccine induction of memory B cells declines with age
- No relationship between post-vaccine IgG levels and memory B cells in SARS-CoV-2 inexperienced people
- Memory B cells strongly correlate with post-vaccination IgG levels in SARS-CoV2 recovered people
- The importance of measuring memory B cells induced by the vaccination is emphasized
So, this means that SARS-CoV-2 recovered people do not need vaccination twice, but SARS-CoV-2 inexperienced people do need vaccination twice definitely.