Ukrainian scientists prove recovery from coronavirus might boost immunity to SARS-CoV-2

A group of scientists from Danylo Halytsky Lviv National Medical University conducted and published a preprint proving the existence of cross-immunity for the coronavirus that caused the 2020 pandemic — SARS-CoV-2.

This is important both for analyzing the chances of contracting the coronavirus and for understanding how vaccines against it should work. “It seems to be the first work of this level on SARS-CoV-2 done in Ukraine,” said biophysicist Semen Yesylevskyy.

AIN.UA spoke with the head of the group, Professor of the Department of Histology, Cytology, and Embryology of LNMU, Rostyslav Bilyi, about what this means for the treatment of coronavirus. Below is a blitz interview with the scientist.

Tell us about your research group, what exactly are you researching?

We specialize in the study of cells responsible for innate human immune protection, in particular neutrophilic granulocytes, lymphocytes, etc.

We participate in two international projects of the Horizon 2020 program, a project of the Ministry of Health of Ukraine. I am the leader of these projects on the Ukrainian side. Our publications include articles in Science, Nature Medicine, Material Today, and other journals. Our 2019 article in the Immunity journal, where we showed that neutrophilic granulocytes initiate the formation of stones in bile ducts, was recognized as the best Immunity article in 2019.

Is it true that your research proves that coronavirus causes cross-immunity? That is, a person exposed to this type of virus can become immune to SARS-CoV-2 coronavirus?

Since 2015, we have been studying vaccine adjuvants, those components that enhance the immune response. In particular, we study adjuvants in the form of nanoparticles, which intensely stimulate human neutrophils and provide a strong immune response.

When we decided a few years ago to test our development in collaboration with colleagues from Pasteur Institute in Lille, we chose the most dangerous pathogen to which it is difficult to obtain an immune response.

It was a coronavirus — the causative agent of the Middle East Respiratory Syndrome (MERS). Although the disease has been localized, the high mortality rate (~ 35%) still makes it extremely dangerous. We successfully obtained an immune response in both mice and rabbits back in 2019.

And then the COVID-19 pandemic unfolded and its causative agent is the closest brother of the MERS virus. Therefore, our predictions about the danger turned out to be true and at the beginning of the pandemic, we had already developed a methodology and available antibodies to one of the coronaviruses. So the idea arose to test the cross-immune response among coronaviruses because it is a fairly typical phenomenon.

The team that carried out this work consisted of my colleagues from LNMU, where the greatest contribution was made by Andriy Rabets, my colleagues from the Ukrainian biotechnology company Explogen, colleagues from the French Academy of Sciences, Professor Sabina Szuneritz and Dr. Sandor Vari of the Cedars-Sinai Medical Center, California.

Our cohort comprises Lviv patients who contracted the coronavirus and were treated at the University’s clinical departments. The main tasks are virus antigen synthesis and testing antibody affinity.

What will your study mean for the treatment of coronavirus? 

As a result, we found that almost all coronaviruses have areas of the so-called spike protein with which the virus attaches to cells with high affinity.

Moreover, these areas are hidden during contact of the virus with the host cell, but after the contact the protein “unfolds” to ensure the penetration of the virus particle into the host cell and at this point these areas become clearly visible to immune cells. Accordingly, they can trigger immunity.

Accordingly, antibodies to a certain type of coronavirus will, to some extent only, recognize other coronaviruses. In this case, patients who recovered from COVID-19 had antibodies that recognized peptides of MERS virus.

And that’s absolutely okay: remember the first vaccine, in 1796 Edward Jenner used a cowpox specimen (less dangerous) to build immunity to real smallpox.

Regarding the practical significance: it is the understanding of why a positive test for immunoglobulin content in the diagnosis of coronavirus requires such a relatively high value of antibodies in the test (usually > 1.4). It is also an understanding of the chances of contracting COVID-19 after coronavirus ARVI, and understanding of why you should not use vaccines against this disease based on coronavirus vectors.