Inactive SARS-CoV-2 vaccine generates high antibody responses in healthcare workers with and without prior infection

Harika Oyku Dinc, Nese Saltoglu, Gunay Can, Ilker Inanc Balkan, Beyhan Budak, Dogukan Ozbey, Bilge Caglar, Rıdvan Karaali, Bilgul Mete, Yesim Tuyji Tok, Yagmur Ersoy, Mert Ahmet Kuskucu, Kenan Midilli, Sevgi Ergin, Bekir Sami Kocazeybek, Harika Oyku Dinc, Nese Saltoglu, Gunay Can, Ilker Inanc Balkan, Beyhan Budak, Dogukan Ozbey, Bilge Caglar, Rıdvan Karaali, Bilgul Mete, Yesim Tuyji Tok, Yagmur Ersoy, Mert Ahmet Kuskucu, Kenan Midilli, Sevgi Ergin, Bekir Sami Kocazeybek

Abstract

Background and objectives: Healthcare workers (HCWs) were among the first groups to be vaccinated in Turkey. The data to be obtained by the vaccination of HCWs would guide wide spread vaccination programs.

Materials and methods: The study included 330 HCWs working at Istanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty Hospital and vaccinated with inactive CoronaVac (Sinovac Life Sciences, China) SARS-CoV-2 vaccine in two doses (28 days apart). Anti-Spike /RBD IgG levels were measured 14 days after the first dose and 28 days after the second dose. Chemiluminescent microparticle immunoassay (CMIA) (ARCHITECT IgG II Quant test, Abbott, USA), which is 100% compatible with plaque reduction neutralization test (PRNT), was used.

Results: Of the participants, 211 (63.9%) were female, 119 (36.1%) were male, and mean age was 39.6 ± 7.7 years. In those without prior COVID-19 history; (n = 255) antibody positivity was detected as 48.2% (95% CI: 42.1-54.3) 14 days after the first dose of vaccine, and 99.2% (95% CI: 98.1-100) at day 28 after the second dose. Antibody titers were significantly lower in patients with hypertension (p = 0.011). In those with prior history of COVID-19 (n = 75); both the antibody positivity rates after the first vaccine (48.2% vs 100%, p = 0.000) and the anti-spike/RBD antibody levels after the second vaccine (with a ≥ 1050 AU/mL titer equivalent to PRNT 1/80 dilution) was significant than infection-naive group (25.9% vs. 54.7%, p = 0.000). Antibody positivity after two doses of vaccination for all study group was 99.4% (95% CI: 98.6-100).

Conclusions: Two doses CoronaVac produce effective humoral immunity in HCWs. Antibody response is significantly higher in those with prior history of COVID-19 than infection-naive group. Given no significant benefit of the second dose, a single shot of vaccination may be sufficient for those with prior history of COVID-19. Monitoring humoral and cellular immune responses, considering new variants, is required to validate this approach.

Keywords: COVID-19; Chemiluminescent microparticle immunoassay; CoronaVac; Healthcare workers; the anti-spike/RBD antibody.

Conflict of interest statement

Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Copyright © 2021 Elsevier Ltd. All rights reserved.

Figures

Fig. 1
Fig. 1
Flowchart of volunteers participating in the Inactive SARS-CoV-2 Vaccine Efficacy Study.
Fig. 2
Fig. 2
SARS-CoV-2 IgG averages in blood samples taken at different times from healthcare workers who have prior history of COVID-19 and who are infection naïve.
Fig. 3
Fig. 3
SARS-CoV-II (RBD) IgG results by depending on viral contact in the Infection-Naive group.

References

    1. Walker P.G.T., Whittaker C., Watson O.J., Baguelin M., Winskill P., Hamlet A., et al. The impact of COVID-19 and strategies for mitigation and suppression in low- and middle-income countries. Science. 2020;369(6502):413–422. doi: 10.1126/science:abc0035.
    1. Coronavirus disease (COVID-2019) situation reports. [Accessed 4 Oct 2021]
    1. Republic of Turkey, Ministry of Health COVID-19 Information Platform [Accessed 4 Oct 2021]
    1. Zhang Y., Zeng G., Pan H., Li C., Hu Y., Chu K., et al. Safety, tolerability, and immunogenicity of an inactivated SARS-CoV-2 vaccine in healthy adults aged 18–59 years: a randomised, double-blind, placebo-controlled, phase 1/2 clinical trial. Lancet Infect Dis. 2021;21(2):181–192. doi: 10.1016/S1473-3099(20)30843-4.
    1. WHO. Evidence Assessment: Sinovac/CoronaVac COVID-19 vaccine. [Accessed 2 June 2021]
    1. World Health Organization (2020). Establishment of the WHO International Standard and Reference Panel for anti-SARS-CoV-2 antibody. WHO/BS/2020.2403. Available at: [Accessed 2 June 2021]
    1. Abbott SARS-CoV-2 Immunoassays [Accessed 2 June 2021]
    1. Dinç HÖ, Özdemir YE, Alkan S, Güngördü Dalar Z, Gareayaghi N, Sirekbasan S . Evaluation of the Diagnostic Performance of Different Principles of SARS-CoV-2 Commercial Antibody Tests in COVID-19 Patients. 2021;55(2):207-222/doi: 10.5578/mb.20219907
    1. Bhimraj A, Morgan RL, Shumaker AH, Lavergne V, Baden L, Cheng VC et al. Infectious Diseases Society of America Guidelines on the Treatment and Management of Patients with COVID-19. Infectious Diseases Society of America 2021; Version 4.2.0. Available at [Accessed 2 June 2021]
    1. WHO. Strategic Advisory Group of Experts on Immunization (SAGE): COVID-19 vaccines technical documents. [Accessed 2 June 2021]
    1. Aran D. Estimating real-world COVID-19 vaccine effectiveness in Israel. medRxiv preprint doi:
    1. Hitchings MDT, Ranzani OT, Scaramuzzini Torres MS, Barbosa de Oliveira S, Almiron M, Said R . Effectiveness of CoronaVac in the setting of high SARS-CoV- 2 P.1 variant transmission in Brazil: A test-negative case-control study. MedRxiv preprint doi: this version posted April 7, 2021.
    1. Al Kaabi N., Zhang Y., Xia S., Yang Y., Al Qahtani M.M., Abdulrazzaq N., et al. Effect of 2 Inactivated SARS-CoV-2 Vaccines on Symptomatic COVID-19 Infection in Adults: A Randomized Clinical Trial. JAMA. 2021;326(1):35. doi: 10.1001/jama.2021.8565.
    1. Gao Q., Bao L., Mao H., Wang L., Xu K., Yang M., et al. Development of an inactivated vaccine candidate for SARS-CoV-2. Science. 2020;369(6499):77–81. doi: 10.1126/science:abc1932.
    1. Tan Y.-J., Goh P.-Y., Fielding B.C., Shen S., Chou C.-F., Fu J.-L., et al. Profiles of antibody responses against severe acute respiratory syndrome coronavirus recombinant proteins and their potential use as diagnostic markers. Clin Diagn Lab Immunol. 2004;11(2):362–371. doi: 10.1128/CDLI.11.2.362-371.2004.
    1. Wu H.-S., Hsieh Y.-C., Su I.-J., Lin T.-H., Chiu S.-C., Hsu Y.-F., et al. Early detection of antibodies against various structural proteins of the SARS-associated coronavirus in SARS patients. J Biomed Sci. Jan-Feb. 2004;11(1):117–126. doi: 10.1007/BF02256554.
    1. Liu L., Liu W., Zheng Y., Jiang X., Kou G., Ding J., et al. A preliminary study on serological assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 238 admitted hospital patients. Microbes Infect. May-Jun. 2020;22(4-5):206–211. doi: 10.1016/j.micinf.2020.05.008.
    1. Lumley S.F., O’Donnell D., Stoesser N.E., Matthews P.C., Howarth A., Hatch S.B., et al. Antibody Status and Incidence of SARS-CoV-2 Infection in Health Care Workers. N Engl J Med. 2021;384(6):533–540. doi: 10.1056/NEJMoa2034545.
    1. Hall V.J., Foulkes S., Charlett A., Atti A., Monk E.J.M., Simmons R., et al. SARS-CoV-2 infection rates of antibody-positive compared with antibody-negative health-care workers in England: a large, multicentre, prospective cohort study (SIREN) Lancet. 2021;397(10283):1459–1469. doi: 10.1016/S0140-6736(21)00675-9.
    1. CDC. About COVID-19 Vaccine: requently Asked Questions about COVID-19 Vaccination. (Updated May 12, 2021) [Accessed 2 June 2021]
    1. Zhang H, Hu Y, Jiang Z, Shi N, Lin H, Liu Y et al. Single-Cell Sequencing and Immune Function Assays of Peripheral Blood Samples Demonstrate Positive Responses of an Inactivated SARS-CoV-2 Vaccine. Available at SSRN: or .
    1. Kristiansen P.A., Page M., Bernasconi V., Mattiuzzo G., Dull P., Makar K., et al. WHO International Standard for anti-SARS-CoV-2 immunoglobulin. Lancet. 2021;397(10282):1347–1348. doi: 10.1016/S0140-6736(21)00527-4.
    1. FDA. Convalescent Plasma. [Accessed 2 June 2021]

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