Chemaitelly et al.: "Long-term COVID-19 booster effectiveness by infection history and clinical vulnerability and immune imprinting"; protection against infection waned after the booster, and

by Paul Alexander

eventually suggested an imprinting effect of compromised protection relative to the primary series." lay man terms it means booster failed on Pfizer & Moderna with Original antigenic sin dominating


Look at negative effectiveness months 7 and 8 onwards and the plunge, both mRNA vaccines.

‘Booster effectiveness relative to primary series was 41.1% (95% CI: 40.0-42.1%) against infection and 80.5% (95% CI: 55.7-91.4%) against severe, critical, or fatal COVID-19, over one-year follow-up after the booster. Among persons clinically vulnerable to severe COVID-19, effectiveness was 49.7% (95% CI: 47.8-51.6%) against infection and 84.2% (95% CI: 58.8-93.9%) against severe, critical, or fatal COVID-19. Effectiveness against infection was highest at 57.1% (95% CI: 55.9-58.3%) in the first month after the booster but waned thereafter and was modest at only 14.4% (95% CI: 7.3-20.9%) by the sixth month. In the seventh month and thereafter, coincident with BA.4/BA.5 and BA.2.75* subvariant incidence, effectiveness was progressively negative reaching -20.3% (95% CI: -55.0-29.0%) after one year of follow-up.’

Booster against Pfizer:

Booster against Moderna: