AUTHOR=Zhang Zhe , Wu Shipo , Liu Yawei , Li Kailiang , Fan Pengfei , Song Xiaohong , Wang Yudong , Zhao Zhenghao , Zhang Xianwei , Shang Jin , Zhang Jinlong , Xu Jinghan , Li Yao , Li Yaohui , Zhang Jipeng , Fu Kefan , Wang Busen , Hao Meng , Zhang Guanying , Long Pengwei , Qiu Ziyu , Zhu Tao , Liu Shuling , Zhang Yue , Shao Fangze , Lv Peng , Yang Yilong , Zhao Xiaofan , Sun Yufa , Hou Lihua , Chen Wei 

TITLE=Boosting with an aerosolized Ad5-nCoV elicited robust immune responses in inactivated COVID-19 vaccines recipients

JOURNAL=Frontiers in Immunology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2023.1239179

DOI=10.3389/fimmu.2023.1239179

ISSN=1664-3224

ABSTRACT=<sec><title>Introduction</title><p>The SARS-CoV-2 Omicron variant has become the dominant SARS-CoV-2 variant and exhibits immune escape to current COVID-19 vaccines, the further boosting strategies are required.</p></sec><sec><title>Methods</title><p>We have conducted a non-randomized, open-label and parallel-controlled phase 4 trial to evaluate the magnitude and longevity of immune responses to booster vaccination with intramuscular adenovirus vectored vaccine (Ad5-nCoV), aerosolized Ad5-nCoV, a recombinant protein subunit vaccine (ZF2001) or homologous inactivated vaccine (CoronaVac) in those who received two doses of inactivated COVID-19 vaccines. </p></sec><sec><title>Results</title><p>The aerosolized Ad5-nCoV induced the most robust and long-lasting neutralizing activity against Omicron variant and IFNg T-cell response among all the boosters, with a distinct mucosal immune response. SARS-CoV-2-specific mucosal IgA response was substantially generated in subjects boosted with the aerosolized Ad5-nCoV at day 14 post-vaccination. At month 6, participants boosted with the aerosolized Ad5-nCoV had remarkably higher median titer and seroconversion of the Omicron BA.4/5-specific neutralizing antibody than those who received other boosters. </p></sec><sec><title>Discussion</title><p>Our findings suggest that aerosolized Ad5-nCoV may provide an efficient alternative in response to the spread of the Omicron BA.4/5 variant.</p></sec><sec><title>Clinical trial registration</title><p><uri xlink:href="https://www.chictr.org.cn/showproj.html?proj=152729" xmlns:xlink="http://www.w3.org/1999/xlink">https://www.chictr.org.cn/showproj.html?proj=152729</uri>, identifier ChiCTR2200057278.</p></sec>