Safety, immunogenicity and immune-persistence of heterologous prime-boost immunization with BBIBP-CorV and ZF2001 against SARS-CoV-2 in healthy adults aged 18 years or older

ABSTRACT

Background

Because SARS-CoV-2 mutations and immunity wane over time, a third dose of heterologous COVID-19 vaccine is proposed for individuals primed with inactivated COVID-19 vaccine.

Research design and methods

We conducted a single-center, open-label trial to assess the safety, immunogenicity, and immune-persistence of a heterologous BBIBP-CorV/ZF2001 prime-boost vaccination in Chinese adults. 480 participants who had been primed with two doses of BBIBP-CorV, received a third dose of ZF2001 after an interval of 3–4, 5–6, or 7–9 months.

Results

The overall incidence of adverse reactions within 30 days after vaccination was 5.83%. No serious adverse reactions were reported. The respective geometric mean titers (GMTs) of neutralizing antibodies for 3–4, 5–6, and 7–9 months groups at baseline were 2.06, 2.02, and 2.10; which increased to 55.42, 63.45, and 62.06 on day 14; then decreased to 17.53, 23.79, and 26.73 on day 30; before finally waning to 8.29, 9.24, and 9.51 on day 180. After the booster, the three groups showed no significant differences in GMTs. GMTs were lower in older participants than younger participants.

Conclusions

A heterologous BBIBP-CorV/ZF2001 prime-boost vaccination was safe and immunogenic. Prime-boost intervals did not affect the immune response. The immune response was weaker in older adults than younger adults.

Clinical trial identifier

NCT05205083

KEYWORDS:

• COVID-19
• heterologous booster
• immune-persistence
• immunogenicity
• safety

Acknowledgments

We thank Anhui Zhifei Longcom Biopharmaceuticals for providing the ZF2001 vaccines and Guangdong Provincial Institute of Public Health for conducting the live virus experiments. We thank all the investigators from Shangyu District Center for Disease Control and Prevention, Yonghe community health center and Yiting community health center.

Declaration of interest

L Gong, L Yuan and G Chen are employees of Anhui Zhifei Longcom Biopharmaceutical Co., Ltd who provided the ZF2001 vaccines. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or material discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

Yingping Chen conceptualized and designed the study, data collection, analysis and interpreted the data, drafted the manuscript. Xinpei Zhang recruited participants and conducted the study, reviewed the manuscript. Lihui Gong participated in the conceptualization and design of the study, reviewed the manuscript. Zhenzhen Liang, Xiaosong Hu, Bo Xing and Yuting Liao participated in data collection, analysis, and interpretation, reviewed the manuscript. Lingfeng Yuan and Gang Chen participated in data interpretation, reviewed the manuscript. Huakun LV conceptualized and designed the study, coordinated, and supervised data collection, critically reviewed the manuscript. All authors have read and agreed to the published version of the manuscript.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/14760584.2023.2274491

Additional information

Funding

This manuscript was funded by the Key Program of Health Commission of Zhejiang Province/Science Foundation of National Health Commission under grant number WKJ-ZJ-2221; Medical and Health Science and Technology Program of Zhejiang Province under grant number 2022KY713.