COVID-19 Vaccines: Challenges and Opportunities

At the height of the global pandemic, vaccination, which has already started in Lithuania, is emerging as the key weapon to fight the coronavirus pandemic. Therefore, the most important questions related to vaccination become even more relevant. Aurelija Žvirblienė, professor at the Faculty of Medicine of Vilnius University (VU MF) answers these questions in a remote lecture-discussion “COVID-19 vaccine: Challenges and new trends in vaccinology” and dispels doubts about the effectiveness of vaccination and the prospects for a secure future.

In Lithuania, COVID-19 vaccines were first received by the country’s health care workers and will soon be available to a wider public. According to Prof A. Žvirblienė, the global pandemic requires rapid technological solutions, so mass vaccination is a necessity that must be carried out in the whole world.

“The only way to control the pandemic is to have a large number of virus-resistant, immune people. This could be achieved with many having COVID-19, but the cost of herd immunity gained in this way would be too high – many deaths. Therefore, the main weapon against the pandemic is vaccination,” says the professor.

Prof A. Žvirblienė compares the body’s immune system to an “army”, which must be ready to repel attacking viruses. In this case, vaccines have a role to play in “training” the immune system to defend itself against pathogens, in other words, vaccination gives rise to a “training defence exercise” in the human body.

“Our immune system is very complex, consisting of two interrelated parts: innate immunity, the body’s “frontier army”, and acquired immunity, the more advanced part of the immune system that seems to teach the body the secrets of combat,” explains the scientist.

Innate immunity acts first during infection and provides rapid protection against the virus in the early hours. Acquired immunity takes effect within a few days. It consists of B and T lymphocytes, which provide accurate, specific and significantly longer and more effective defence of the body because of their wide variety of receptors, which allow the recognition of billions of different antigens. B lymphocytes produce antibodies that can neutralize viruses or bacteria, while T lymphocytes kill infected cells and help other cells in the immune system to function. These lymphocytes also form immune memory.

“By mimicking microbes but not causing disease, vaccines activate B and T lymphocytes, promote the formation of memory lymphocytes that live long and protect us from disease,” Prof A. Žvirblienė says, stressing the importance of getting the second dose of the vaccine because it strengthens the immune response.

The professor emphasizes that the accumulated baggage of epidemiological knowledge in the modern world and high-level technological advances in medicine and vaccinology help to overcome threats to human health and existence. A great example of this is the way to overcome the coronavirus pandemic, which has been found in a record period of time – one year.

When speaking about the types of vaccines, Prof A. Žvirblienė emphasizes that COVID-19 vaccines are innovative and developed taking into account the real threat to humanity: “They are clinically proven to be quite effective in protecting the body against the virus in people of all ages.Scientists all over the world are convinced: herd immunity stops the spread of the pathogen and protects public health,” VU researcher concludes.

Prof Žvirblienė has no doubt that new technologies of vaccination are just the beginning of the fight against the virus. In a special lecture, the professor talks about how vaccines from different manufacturers work, why we need to be vaccinated, what experience we have already gained about vaccines and what tasks we will have to solve in the future.