McLeod C, Dymock M, Flanagan K L, Plebanski M, Marshall H, Estcourt M J, Tjiam M C, Blyth C C, Subbarao K, Mordant F L, Nicholson S, Faust S N, Wadia U, Thornton R B, Ellis Z, Mckenzie A, Marsh J A, Snelling T L, Richmond P
Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, Nedlands, Australia; Infectious Diseases Department, Perth Children's Hospital, Nedlands, Australia; School of Medicine, University of Western Australia, Crawley, Australia.
Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, Nedlands, Australia.
J Infect. 2024 Dec;89(6):106286. doi: 10.1016/j.jinf.2024.106286. Epub 2024 Sep 26.
PICOBOO is a randomised, adaptive trial evaluating the immunogenicity, reactogenicity, and safety of COVID-19 booster strategies. We report data for second boosters among individuals 50-<70 years old primed with AZD1222 (50-<70y-AZD1222) until Day 84.
Immunocompetent adults who received any first booster ≥three months prior were eligible. Participants were randomly allocated to BNT162b2, mRNA-1273 or NVX-CoV2373 1:1:1. The concentrations of ancestral anti-spike immunoglobulin were summarised as the geometric mean concentrations (GMC). Reactogenicity and safety outcomes were captured. Additional analyses including neutralising antibodies were performed on a subset. ACTRN12622000238774.
Between Mar 2022 and Aug 2023, 743 participants were recruited and had D28 samples; 155 belonged to the 50-<70y-AZD1222 stratum. The mean adjusted GMCs (95% credible intervals) were 20,690 (17 555-23 883), 23,867 (20 144-27 604) and 8654 (7267-9962) U/mL at D28 following boosting with BNT162b2, mRNA-1273 and NVX-CoV2372, respectively, and 10,976 (8826-13 196), 15,779 (12 512-19 070) and 6559 (5220-7937) U/mL by D84. IgG against Omicron BA.5 was 2.7-2.9 times lower than the ancestral strain. Limited neutralisation against Omicron subvariants was found following all vaccines. Severe reactogenicity events were <4%.
All vaccines were immunogenic with more rapid waning after mRNA vaccines. These data support boosting with vaccines with greater specificity for circulating Omicron subvariants.
PICOBOO是一项随机、适应性试验，评估新冠病毒加强免疫策略的免疫原性、反应原性和安全性。我们报告了50至70岁（未满70岁）接种AZD1222（50-<70y-AZD1222）作为初始疫苗接种的人群中第二剂加强针的数据，随访至第84天。
符合条件的为在至少三个月前接种过任何第一剂加强针的免疫功能正常的成年人。参与者按1:1:1随机分配至BNT162b2、mRNA-1273或NVX-CoV2373组。将原始抗刺突免疫球蛋白浓度汇总为几何平均浓度（GMC）。记录反应原性和安全性结果。对一个亚组进行了包括中和抗体在内的额外分析。澳大利亚新西兰临床试验注册中心编号：ACTRN12622000238774。
2022年3月至2023年8月期间，招募了743名参与者并采集了第28天的样本；155名属于50-<70y-AZD1222组。加强接种后第28天，使用BNT162b2、mRNA-1273和NVX-CoV2372加强接种后的平均校正GMC（95%可信区间）分别为20,690（17 555-23 883）、23,867（20 144-27 604）和8654（7267-9962）U/mL，到第84天分别为10,976（8826-13 196）、15,779（12 512-19 070）和6559（5220-7937）U/mL。针对奥密克戎BA.5的IgG比原始毒株低2.7至2.9倍。所有疫苗接种后对奥密克戎亚变体的中和作用有限。严重反应原性事件发生率低于4%。
所有疫苗均具有免疫原性，mRNA疫苗接种后免疫原性下降更快。这些数据支持使用对循环中的奥密克戎亚变体具有更高特异性的疫苗进行加强接种。
