How to Overcome New Viruses Wisely: Exploring the Inner World That Fights Against Pandemics

It has been four years since the COVID-19 pandemic shook the world with fear. Thanks to the development of vaccines, daily life returned to some normalcy after about two years. However, the SARS-CoV-2 virus continues to linger around us, evolving into new variants. From Omicron subvariants like BA.1 and BA.2 to BA.4, BA.5, XBB, JN.1, and more recently KP.3, the virus continues to mutate, waiting for opportunities to infect. Despite this, recent research from the Center for Viral Immunology within the Korea Virus Research Institute of the Institute for Basic Science (IBS) reveals that our immune system remembers past viral encounters and can mount a defense against new variants. This shows that our bodies are just as formidable as the virus itself.

The IBS Korea Virus Research Institute Center for Viral Immunology discovered that memory T cells, formed after breakthrough infections of Omicron, exhibit strong immune responses to newer Omicron variants. A breakthrough infection occurs when someone gets infected despite having antibodies from vaccination. By isolating immune cells from individuals who experienced BA.2 breakthrough infections, the researchers found that these memory T cells responded robustly not only to BA.2 but also to subsequent variants like BA.4 and BA.5. This means the immune system can mount strong responses even against slightly different, previously unseen viruses.

Dr. JUNG Min Kyung, who led the study, explained, “It’s not just the virus that evolves—our immune system adapts to the virus's rapid mutations.” Dr. Jung shared insights about the significance of the study and strategies to combat increasingly frequent viral threats.

Please introduce yourself.
Hello, I earned my master’s and Ph.D. in immunology and worked as a research assistant professor at KAIST's Graduate School of Medical Science and Engineering before joining the Center for Viral Immunology at IBS in 2021. I’ve been conducting research on virus immunity since then.

What brought you to IBS.
I’ve always been fascinated by immune research in infectious diseases. Throughout history, humans have been in a constant battle with infectious diseases, and advances in science and medicine have been pivotal in this fight. This drew me to study infectious diseases.

I had been researching T cells' roles in various bacterial and viral infections when the COVID-19 pandemic hit, leading to the establishment of the IBS Korea Virus Research Institute. I joined as an early member of the institute. Since then, I’ve been studying the immune system's responses to viral infections, including COVID-19 variants, even in the endemic phase.

What kind of place is the IBS Korea Virus Research Institute.
Before the pandemic, many believed we were living in a safe environment. However, the COVID-19 pandemic revealed our vulnerability to new viral threats. This prompted a consensus that long-term, foundational scientific research capabilities were needed to combat such threats. Consequently, the IBS Korea Virus Research Institute was established as a national strategic research hub to prepare for future pandemics.

The Center for Viral Immunology is one of the Institute’s Centers. We focus on studying immune responses to viruses and the immune mechanisms underlying viral diseases.

What are some of your representative studies.
During the COVID-19 pandemic, there was widespread concern about Omicron breakthrough infections, sparking debates about “ineffective vaccines.” The pressing question was, “Are vaccines truly ineffective?” Researchers, including myself, reported that while vaccines might not prevent Omicron infections, they could still prevent severe disease.

Later, as Omicron variants emerged and breakthrough infections continued, a new question arose: “How do people who experienced breakthrough infections with early Omicron variants respond to subsequent variants?” To answer this, we isolated and analyzed immune cells from individuals who had breakthrough infections with early Omicron variants. We discovered that memory T cells from these individuals mounted strong immune responses even to newer variants.

Immunity granted by vaccination generally include antibodies and memory T cells. While neutralizing antibodies, which block infection at the cellular level, have traditionally been the focus of vaccine research, we shifted our attention to memory T cells. Unlike neutralizing antibodies, memory T cells do not prevent infections but selectively target and eliminate infected cells to inhibit viral replication.

What motivated you to start this study.
My approach to research is to address questions that intrigue both myself and many people. During the pandemic, there was immense interest in vaccines and their effectiveness, raising many questions. This study sought to provide scientific answers through experiments. I believe offering scientifically grounded insights is one of the meaningful contributions scientists can make.

How has the academic community received this research.
Our findings demonstrate that individuals who experienced early Omicron breakthrough infections are less likely to develop severe illness when infected with similar new variants. As new Omicron subvariants continued to emerge after our study was published, the societal impact of this research has been substantial.

Additionally, our research suggests a potential direction for vaccine development. By focusing on similarities between dominant variants and their lineages, we can leverage memory T cells to provide protection against future variants.

Were there any challenges during the study.
This study required experiments on immune cells extracted from actual human blood samples, not cell lines or animal models. Collaborating with university hospitals across the country, we collected blood samples from patients and medical staff, isolating immune cells from these samples. Coordinating this large-scale collaboration and securing sufficient samples required significant effort.

I’m deeply grateful to the fellow researchers, collaborators, and students who supported this work. The results reflect their hard work and dedication.

What are your future research plans.
Currently, I’m studying how immunity changes after repeated exposures to COVID-19 antigens. Over the past three years, most people have been vaccinated at least three times and may have also experienced breakthrough infections. Understanding how repeated exposure impacts immunity is crucial.

I’m also researching T-cell-targeted vaccine development and the immune response to emerging Omicron subvariants.

While the pandemic may be over, its long-term consequences remain uncertain, making ongoing research and observation essential. For the next few years, I plan to focus on studies leveraging the resources gathered during the pandemic.

Any final thoughts.
Scientific achievements are not made by scientists alone. They depend on public interest and support. We don’t know when the next pandemic will strike. To prepare, continuous support and attention from the public and government are essential.