Immune response and safety of inactivated SARS-CoV-2 vaccines during pregnancy: a real-world observational study

ABSTRACT

Background

As pregnant women are excluded from clinical trials of inactivated SARS-CoV-2 vaccines, it is important to assess the immune response in women receiving the vaccination while unknowingly pregnant.

Methods

In a multicenter cross-sectional study, we enrolled 873 pregnant women aged 18–45 years. Serum antibody levels induced by inactivated vaccines were determined. Adverse events were collected by self-reported survey after vaccination. Logistic regression model and restricted cubic spline model were used to investigate the association of factors with antibody positivity.

Results

As the doses of the vaccine increase, neutralizing antibody (NAb) positivity was 98.3%, 39.5%, and 9.5% in pregnant women, respectively. The dose of vaccine and duration since vaccination were associated with NAb positivity. The OR of two and three doses of vaccines were 7.20 and 458.33 (P < 0.05). NAb levels and duration since vaccination showed a linear relationship in pregnant women vaccinated two doses, with a decrease to a near seropositivity threshold at 22 weeks. Adverse events were mainly mild or moderate after vaccinated during pregnancy, with no increase in incidence compared with whom vaccinated during pre-pregnancy.

Conclusions

The use of inactivated vaccines during pregnancy induced favorable immune persistence, and the incidence of adverse events did not increase.

KEYWORDS:

• Coronavirus disease 2019 (COVID-19)
• inactivated vaccine
• pregnancy
• immune response
• safety

Declaration of interests

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

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

Author contributions

All authors contributed to the study conception, design, data acquisition, analysis, interpretation, and drafting and revising the manuscript.

All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this article, take responsibility for the integrity of the work as a whole, and have given their approval for this version to be published.

Availability of data and materials

De-identified data collected for the study (with data dictionary) might be made available upon approval by the study investigators, with relevant agreements (eg, data sharing agreement) and approvals (eg, relevant ethics approvals). Requests should be directed to the corresponding author in the first instance.

Ethics approval and consent to participate

The study was approved by the Medical Ethics Review Board of the School of Public Health, Guangdong Pharmaceutical University (IRB 2021–01), and complied with the Declaration of Helsinki guidelines. All participants signed consent forms.

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/14760584.2023.2272655.

Additional information

Funding

This manuscript was funded by Medical Science and Technology Foundation of Guangdong Province (No.2019GCZX012 (QSC)), Guangdong Medical Products Administration (No.2022TDZ21) ，Exposure to SARS-CoV-2 vaccine before or during pregnancy and adverse pregnancy outcomes: a cohort study (No.41-43241529) and the 2022 Science and Technology Innovation Project of Guangdong Medical Products Administration“Research and application of key technology and evaluation system of pharmacovigilance”(No. 2022ZDZ06).