Department of Medicine E and Infectious Diseases Unit, Beilinson Hospital, Petah Tikva, Israel.
Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BMJ Open. 2022 Aug 2;12(8):e061584. doi: 10.1136/bmjopen-2022-061584.
To evaluate the durability of response 3 months after the third BNT162b2 vaccine in adults aged 60 years and older.
Prospective cohort study.
Single tertiary centre.
Healthcare workers/family members aged ≥60 years old who received the third BNT162b2 dose.
Blood samples were drawn immediately before (T0), 10-19 days (T1) and 74-103 days (T2) after the third dose.
Anti-spike IgG titres were determined using a commercial assay and seropositivity was defined as ≥50 arbitrary units (AU)/mL. Neutralising antibody titres were determined at T2. Adverse events, COVID-19 infections and Clinical Frailty Scale (CFS) levels were documented.
The analysis included 97 participants (median age, 70 years (IQR, 66-74), 58% CFS level 2). IgG titres, which increased significantly from T0 to T1 (median, 440 AU/mL (IQR, 294-923) and median, 25 429 AU/mL (IQR, 14 203-36 114), respectively; p<0.001), decreased significantly by T2, but all remained seropositive (median, 8306 AU/mL (IQR, 4595-14 701), p<0.001 vs T1). In a multivariable analysis, only time from the second vaccine was significantly associated with lower IgG levels at T2 (p=0.017). At T2, 60 patients were evaluated for neutralising antibodies; all were seropositive (median, 1294 antibody titres; IQR, 848-2072). Neutralising antibody and anti-spike IgG levels were correlated (r=0.6, p<0.001). No major adverse events or COVID-19 infections were reported.
Anti-spike IgG and neutralising antibody levels remain adequate 3 months after the third BNT162b2 vaccine in healthy adults aged ≥60 years, although the decline in IgG is concerning. A third dose of vaccine in this population should be top priority.
评估 60 岁及以上成年人第三次接受 BNT162b2 疫苗后 3 个月时的反应持久性。
前瞻性队列研究。
单中心三级医院。
≥60 岁接受第三次 BNT162b2 剂量的医护人员/家属。
在第三次剂量前（T0）、10-19 天（T1）和 74-103 天（T2）立即抽取血样。
使用商业检测法测定抗刺突 IgG 滴度，将血清阳性定义为≥50 个任意单位（AU）/mL。在 T2 时测定中和抗体滴度。记录不良事件、COVID-19 感染和临床虚弱量表（CFS）水平。
分析纳入 97 名参与者（中位年龄 70 岁（IQR，66-74），58% CFS 水平 2）。IgG 滴度从 T0 到 T1 显著增加（中位数分别为 440 AU/mL（IQR，294-923）和 25 429 AU/mL（IQR，14 203-36114）；p<0.001），到 T2 时显著下降，但均保持血清阳性（中位数 8306 AU/mL（IQR，4595-14701）；p<0.001 与 T1 相比）。多变量分析显示，只有第二次疫苗接种后的时间与 T2 时较低的 IgG 水平显著相关（p=0.017）。在 T2 时，对 60 名患者进行了中和抗体评估；均为血清阳性（中位数 1294 个抗体滴度；IQR，848-2072）。中和抗体和抗刺突 IgG 水平呈相关性（r=0.6，p<0.001）。未报告重大不良事件或 COVID-19 感染。
健康≥60 岁成年人第三次接受 BNT162b2 疫苗后 3 个月，抗刺突 IgG 和中和抗体水平仍然足够，尽管 IgG 下降令人担忧。该人群应优先接种第三剂疫苗。
