Lee Nelson, Nguyen Lena, Nasreen Sharifa, Austin Peter C, Brown Kevin A, Buchan Sarah A, Grewal Ramandip, Schwartz Kevin L, Tadrous Mina, Wilson Kumanan, Wilson Sarah E, Kwong Jeffrey C
Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
ICES, Toronto, Ontario, Canada.
Vaccine. 2025 Jul 11;60:127300. doi: 10.1016/j.vaccine.2025.127300. Epub 2025 May 26.
We estimated XBB.1.5 vaccine effectiveness (VE) against hospitalization/death among adults aged ≥50 years in Ontario, Canada, from September 2023 to June 2024. Compared with non-XBB.1.5 vaccinees, the initial protection at 0-3 months was 64 % (95 %CI, 57 %-69 %) during XBB-sublineage predominance. It was reduced to 57 % (95 %CI, 48 %-64 %) when JN/KP-sublineages became predominant, and quickly declined. No significant protection was observed >6 months post-vaccination. The VE estimates were lower when the last vaccine dose in the reference group was given more recently than 12 months, or was the omicron-containing bivalent vaccine. Short durability of protection poses unique challenges for COVID-19 vaccination.
我们评估了2023年9月至2024年6月期间，加拿大安大略省≥50岁成年人中XBB.1.5疫苗针对住院/死亡的有效性（VE）。与未接种XBB.1.5疫苗的人相比，在XBB亚谱系占主导期间，0至3个月时的初始保护率为64%（95%CI，57%-69%）。当JN/KP亚谱系占主导时，该保护率降至57%（95%CI，48%-64%），并迅速下降。接种疫苗6个月后未观察到显著保护作用。当参考组中最后一剂疫苗接种时间在12个月以内，或为含奥密克戎的二价疫苗时，VE估计值较低。保护作用的短持久性给新冠疫苗接种带来了独特挑战。
