Central Virology Laboratory, Public Health Services, Ministry of Health, Sheba Medical Center, Tel HaShomer, Israel.
Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.
Nat Immunol. 2022 Jun;23(6):940-946. doi: 10.1038/s41590-022-01212-3. Epub 2022 May 9.
As the effectiveness of a two-dose messenger RNA (mRNA) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine regimen decreases with time, a third dose has been recommended. Here, we assessed immunogenicity, vaccine effectiveness and safety of the third BNT162b2 vaccine dose in a prospective cohort study of 12,413 healthcare workers (HCWs). Anti-RBD immunoglobulin G (IgG) levels were increased 1.7-fold after a third dose compared with following the second dose. Increased avidity from 61.1% (95% confidence interval (CI), 56.1-66.7) to 96.3% (95% CI, 94.2-98.5) resulted in a 6.1-fold increase in neutralization titer. Peri-infection humoral markers of 13 third-dose Delta variant of concern (VOC) breakthrough cases were lower compared with 52 matched controls. Vaccine effectiveness of the third dose relative to two doses was 85.6% (95% CI, 79.2-90.1). No serious adverse effects were reported. These results suggest that the third dose is superior to the second dose in both quantity and quality of IgG antibodies and safely boosts protection from infection.
随着两剂信使 RNA（mRNA）严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）疫苗方案的有效性随时间降低，已建议接种第三剂。在此，我们在一项针对 12413 名医护人员（HCWs）的前瞻性队列研究中评估了第三剂 BNT162b2 疫苗的免疫原性、疫苗有效性和安全性。与接种第二剂后相比，第三剂后抗 RBD 免疫球蛋白 G（IgG）水平增加了 1.7 倍。亲和力从 61.1%（95%置信区间（CI），56.1-66.7）增加到 96.3%（95% CI，94.2-98.5），导致中和滴度增加了 6.1 倍。与 52 名匹配对照相比，13 例第三剂 Delta 变体关注（VOC）突破病例的感染期体液标志物较低。与两剂相比，第三剂的疫苗有效性为 85.6%（95% CI，79.2-90.1）。未报告严重不良事件。这些结果表明，第三剂在 IgG 抗体的数量和质量上均优于第二剂，并且安全地提高了对感染的保护作用。
