Development of premises for implementation of SARS-CoV-2 serotherapy in Croatia (CoVIg)

Project title: Development of premises for implementation of SARS-CoV-2 serotherapy in Croatia (CoVIg)

Grantor: Croatian Science Foundation

Principal investigator: Beata Halassy, PhD

Duration: 15. 7. 2020. - 14. 1. 2022.

Project's web page:

Research team:  

University of Zagreb, Centre for Research and Knowledge Transfer in Biotechnology

Marija Brgles, PhD, M.Chem                       

Tihana Kurtović, PhD, M.Biol

Tanja Košutić Gulija, PhD, M.Biol

Adela Štimac, PhD, M.Chem

Maja Lang Balija, PhD, DVM        

Sanda Ravlić, PhD, M.Biol             

Sanja Mateljak Lukačević, MSc, M.Biol


Croatian Institute of Transfusion Medicine

Irena Jukić, PhD, MD

Ana Hećimović, PhD, MD

Tomislav Vuk, PhD, MD

University Hospital for Infectious Diseases

Oktavija Rode, PhD, MD

Institute of Immunology           

Ana Vučenović Mijatović, DVM

Mirna Tominac, PhD, M.Biotech

Josipa Ćakarun Miletić, M.Chem

Iva Lugović, M.Biotech  

Anja Britvec Generalić, M.Biotech


Total funding: 1.499.925,00 HRK


Brief description:

Passive immunotherapy is a century-old practice of administering antibodies from exposed convalescents or vaccinated persons to patients susceptible to the disease in question. Specific immunoglobulins, some even from animal sources, have an important role in the treatment of various clinical conditions, including viral diseases (hepatitis A and B, rabies, varicella, infections with respiratory syncytial virus, cytomegalovirus, measles). In situations where vaccines are not available, such as during emerging infections and pandemics (infuenza, SARS-CoV-1, MERS, Ebola), convalescent plasma is being collected from donors who have recovered from the disease, and used to treat different pathogens. The whole world, including Croatia, is facing COVID-19 pandemics induced by so far unknown virus named SARS-CoV-2. Experience from prior outbreaks with other coronaviruses (SARS-CoV-1) shows that such convalescent sera contain neutralising antibodies against relevant virus, and that their use was beneficial in the treated patients.1,2 Therapy with antibody-laden blood of those who have survived an infection has nowadays been considered worldwide.3 Convalescent plasma therapy carries also some risks, but using modern blood-banking technologies these risks are rare and outweighed by the benefits. Production of highly purified immunoglobulin preparation containing a high titer of neutralizing antibodies against SARS-CoV-2 is preferable to convalescent plasma given that these are safer and have higher activity.

The aim of this project is three-fold: (1) to develop and organize COVID-19 convalescent plasma collection, testing and storage in Croatia; (2) to establish relevant methodology to properly estimate SARS-CoV-2 neutralization capacity of both convalescent plasma and purified specific immunoglobulins (CoVIg); (3) to develop an efficient and sustainable process for isolation of immunoglobulins from human hyperimmune (convalescent) plasma in emerging situations at a laboratory scale.

Aim (1) includes organization of ethical and infrastructural issues for preparation of national COVID-19 convalescent plasma bank, properly characterized according to regulatory requirements and screened for the absence of SARS-CoV-2 nucleic acid. In addition, neutralization potency of each plasma sample towards SARS-CoV-2 will be determined by cell-culture based neutralization assay.

Aim (2) includes development of relevant methodology for establishment of reproducible SARS-CoV-2 cultivation and laboratory reference preparation, infective virus quantification, and estimation of antibody neutralization power against SARS-CoV-2. The developed assay for measurement of functional antibodies will be compared to other assays available and used for SARS-CoV-2 specific antibody detection to estimate their relevance and accuracy in seropositivity determination. Established methodology will be reproducible and precise and might become the basis for future research towards novel therapeutics and vaccines.

Aim (3) includes preparation of the prototype product of SARS-CoV-2 specific immunoglobulin that fulfils regulatory demands for existing hyperimmune immunoglobulins, considering particularly protein content, aggregate content, molecular size distribution, potency and purity. The aim is to validate virus inactivation power of critical process steps. The process parameters and methods established and optimized will be readily transferable to the product developmental phase of interested companies and institutions.


1. Casadevall A, Pirofski L, J Clin Invest. 2020;130:1545.

2. Cheng A et al. Eur J Clin Microbiol Infect Dis 2005;24:44

3. Nature. News. 24.03.2020.