TY - JOUR
T1 - Protection of vaccine boosters and prior infection against mild/asymptomatic and moderate COVID-19 infection in the UK SIREN healthcare worker cohort
T2 - October 2023 to March 2024
AU - SIREN Study Group
AU - Kirwan, Peter D.
AU - Foulkes, Sarah
AU - Munro, Katie
AU - Sparkes, Dominic
AU - Singh, Jasleen
AU - Henry, Amanda
AU - Dunne, Angela
AU - Timeyin, Jean
AU - Russell, Sophie
AU - Khawam, Jameel
AU - Blick, Debbie
AU - Otter, Ashley D.
AU - Hettiarachchi, Nipunadi
AU - Cairns, Michelle D.
AU - Jackson, Christopher H.
AU - Seaman, Shaun
AU - Brown, Colin S.
AU - Atti, Ana
AU - Islam, Jasmin
AU - Charlett, Andre
AU - De Angelis, Daniela
AU - Presanis, Anne M.
AU - Hall, Victoria J.
AU - Hopkins, Susan
N1 - Publisher Copyright:
© 2024
PY - 2024/11
Y1 - 2024/11
N2 - Objectives: Bivalent original/BA.4–5 and monovalent XBB.1.5 mRNA boosters were offered to UK healthcare workers (HCWs) in the autumn of 2023. We aimed to estimate booster vaccine effectiveness (VE) and post-infection immunity among the SIREN HCW cohort over the subsequent 6-month period of XBB.1.5 and JN.1 variant circulation. Methods: Between October 2023 to March 2024, 2867 SIREN study participants tested fortnightly for SARS-CoV-2 and completed symptoms questionnaires. We used multi-state models, adjusted for vaccination, prior infection, and demographic covariates, to estimate protection against mild/asymptomatic and moderate SARS-CoV-2 infection. Results: Half of the participants (1422) received a booster during October 2023 (280 bivalent, 1142 monovalent), and 536 (19%) had a PCR-confirmed infection over the study period. Bivalent booster VE was 15.1% (−55.4 to 53.6%) at 0–2 months and 4.2% (−46.4 to 37.3%) at 2–4 months post-vaccination. Monovalent booster VE was 44.2% (95% CI 21.7 to 60.3%) at 0–2 months, and 24.1% (−0.7 to 42.9%) at 2–4 months. VE was greater against moderate infection than against mild/asymptomatic infection, but neither booster showed evidence of protection after 4 months. Controlling for vaccination, compared to an infection >2 years prior, infection within the past 6 months was associated with 58.6% (30.3 to 75.4%) increased protection against moderate infection and 38.5% (5.8 to 59.8%) increased protection against mild/asymptomatic infection. Conclusions: Monovalent XBB.1.5 boosters provided short-term protection against SARS-CoV-2 infection, particularly against moderate symptoms. Vaccine formulations that target the circulating variant may be suitable for inclusion in seasonal vaccination campaigns among HCWs.
AB - Objectives: Bivalent original/BA.4–5 and monovalent XBB.1.5 mRNA boosters were offered to UK healthcare workers (HCWs) in the autumn of 2023. We aimed to estimate booster vaccine effectiveness (VE) and post-infection immunity among the SIREN HCW cohort over the subsequent 6-month period of XBB.1.5 and JN.1 variant circulation. Methods: Between October 2023 to March 2024, 2867 SIREN study participants tested fortnightly for SARS-CoV-2 and completed symptoms questionnaires. We used multi-state models, adjusted for vaccination, prior infection, and demographic covariates, to estimate protection against mild/asymptomatic and moderate SARS-CoV-2 infection. Results: Half of the participants (1422) received a booster during October 2023 (280 bivalent, 1142 monovalent), and 536 (19%) had a PCR-confirmed infection over the study period. Bivalent booster VE was 15.1% (−55.4 to 53.6%) at 0–2 months and 4.2% (−46.4 to 37.3%) at 2–4 months post-vaccination. Monovalent booster VE was 44.2% (95% CI 21.7 to 60.3%) at 0–2 months, and 24.1% (−0.7 to 42.9%) at 2–4 months. VE was greater against moderate infection than against mild/asymptomatic infection, but neither booster showed evidence of protection after 4 months. Controlling for vaccination, compared to an infection >2 years prior, infection within the past 6 months was associated with 58.6% (30.3 to 75.4%) increased protection against moderate infection and 38.5% (5.8 to 59.8%) increased protection against mild/asymptomatic infection. Conclusions: Monovalent XBB.1.5 boosters provided short-term protection against SARS-CoV-2 infection, particularly against moderate symptoms. Vaccine formulations that target the circulating variant may be suitable for inclusion in seasonal vaccination campaigns among HCWs.
KW - Asymptomatic
KW - Cohort study
KW - Healthcare worker
KW - SARS-CoV-2
KW - Symptomatic
KW - Vaccine effectiveness
UR - http://www.scopus.com/inward/record.url?scp=85205694491&partnerID=8YFLogxK
U2 - 10.1016/j.jinf.2024.106293
DO - 10.1016/j.jinf.2024.106293
M3 - Article
C2 - 39343245
AN - SCOPUS:85205694491
SN - 0163-4453
VL - 89
JO - Journal of Infection
JF - Journal of Infection
IS - 5
M1 - 106293
ER -