TY - JOUR
T1 - Effectiveness of homologous/heterologous booster COVID-19 vaccination schedules against severe illness in general population and clinical subgroups in three European countries
AU - Riefolo, Fabio
AU - Castillo-Cano, Belén
AU - Martín-Pérez, Mar
AU - Messina, Davide
AU - Elbers, Roel
AU - Brink-Kwakkel, Dorieke
AU - Villalobos, Felipe
AU - Ingrasciotta, Ylenia
AU - Garcia-Poza, Patricia
AU - Swart-Polinder, Karin
AU - Souverein, Patrick
AU - Saiz, Luis Carlos
AU - Bissacco, Carlo Alberto
AU - Leache, Leire
AU - Tari, Michele
AU - Crisafulli, Salvatore
AU - Grimaldi, Lamiae
AU - Vaz, Tiago
AU - Gini, Rosa
AU - Klungel, Olaf
AU - Martín-Merino, Elisa
N1 - Publisher Copyright:
© 2023
PY - 2023/11/13
Y1 - 2023/11/13
N2 - Using 4 data-sources (Spain, Italy, United Kingdom) data and a 1:1 matched cohort study, we aimed to estimate vaccine effectiveness (VE) in preventing SARS-CoV-2 infections with hospitalisations (±30 days) and death (±56 days) in general population and clinical subgroups with homologous/heterologous booster schedules (Comirnaty-BNT and Spikevax-MOD original COVID-19 vaccines) by comparison with unboosted individuals, during Delta and beginning of Omicron variants. Hazard Ratio (HR, by Cox models) and VE ([1-HR]*100) were calculated by inverse probability weights. Between December 2020-February 2022, in adults without prior SARS-CoV-2 infection, we matched 5.5 million people (>1 million with immunodeficiency, 343,727 with cancer) with a booster (3rd) dose by considering doses 1 and 2 vaccine brands and calendar time, age, sex, region, and comorbidities (immunodeficiency, cancer, severe renal disease, transplant recipient, Down Syndrome). We studied booster doses of BNT and MOD administered after doses 1 and 2 with BNT, MOD, or Oxford-AstraZeneca during a median follow-up between 9 and 16 weeks. BNT or MOD showed VE ranging from 70 to 86% across data sources as heterologous 3rd doses, whereas it was 42–88% as homologous 3rd doses. Depending on the severity and available follow-up, 3rd-dose effectiveness lasted between 1 and 5 months. In people with immunodeficiency and cancer, protection across data sources was detected with both heterologous (VE = 54–83%) and homologous (VE = 49–80%) 3rd doses. Overall, both heterologous and homologous 3rd doses with BTN or MOD showed additional protection against the severe effects of SARS-CoV-2 infections for the general population and for patients at potentially high risk of severe COVID-19 (elderly, people with immunodeficiency and cancer) in comparison with two doses schemes during Delta or early Omicron periods. The early VE after vaccination may be due to less testing among vaccinated pairs and unknown confounders, deserving cautious interpretation. The VE wane over time needs further in-depth research to properly envisage when or whether a booster of those vaccines should be administered.
AB - Using 4 data-sources (Spain, Italy, United Kingdom) data and a 1:1 matched cohort study, we aimed to estimate vaccine effectiveness (VE) in preventing SARS-CoV-2 infections with hospitalisations (±30 days) and death (±56 days) in general population and clinical subgroups with homologous/heterologous booster schedules (Comirnaty-BNT and Spikevax-MOD original COVID-19 vaccines) by comparison with unboosted individuals, during Delta and beginning of Omicron variants. Hazard Ratio (HR, by Cox models) and VE ([1-HR]*100) were calculated by inverse probability weights. Between December 2020-February 2022, in adults without prior SARS-CoV-2 infection, we matched 5.5 million people (>1 million with immunodeficiency, 343,727 with cancer) with a booster (3rd) dose by considering doses 1 and 2 vaccine brands and calendar time, age, sex, region, and comorbidities (immunodeficiency, cancer, severe renal disease, transplant recipient, Down Syndrome). We studied booster doses of BNT and MOD administered after doses 1 and 2 with BNT, MOD, or Oxford-AstraZeneca during a median follow-up between 9 and 16 weeks. BNT or MOD showed VE ranging from 70 to 86% across data sources as heterologous 3rd doses, whereas it was 42–88% as homologous 3rd doses. Depending on the severity and available follow-up, 3rd-dose effectiveness lasted between 1 and 5 months. In people with immunodeficiency and cancer, protection across data sources was detected with both heterologous (VE = 54–83%) and homologous (VE = 49–80%) 3rd doses. Overall, both heterologous and homologous 3rd doses with BTN or MOD showed additional protection against the severe effects of SARS-CoV-2 infections for the general population and for patients at potentially high risk of severe COVID-19 (elderly, people with immunodeficiency and cancer) in comparison with two doses schemes during Delta or early Omicron periods. The early VE after vaccination may be due to less testing among vaccinated pairs and unknown confounders, deserving cautious interpretation. The VE wane over time needs further in-depth research to properly envisage when or whether a booster of those vaccines should be administered.
KW - Booster
KW - Clinical subgroups
KW - COVID-19
KW - Heterologous and homologous vaccine schedule
KW - Real-word data
KW - Retrospective cohort study
KW - Vaccines effectiveness
UR - http://www.scopus.com/inward/record.url?scp=85174331018&partnerID=8YFLogxK
U2 - 10.1016/j.vaccine.2023.10.011
DO - 10.1016/j.vaccine.2023.10.011
M3 - Article
C2 - 37858451
AN - SCOPUS:85174331018
SN - 0264-410X
VL - 41
SP - 7007
EP - 7018
JO - Vaccine
JF - Vaccine
IS - 47
ER -