One of the questions that people ask most often and that causes them anxiety and fear is: Why did the vaccines against COVID-19 come out so quickly ? The answer is: Because science is moving forward.
And if many years ago the Human Genome project lasted 13 years (October 1990 – April 2003), cost billions of dollars and involved thousands of researchers worldwide, thanks to the lessons learned in its implementation and technology development, today relying on the genome lasts for days and its the price is completely affordable for ordinary people. Take a look at your cell phone and computer – see how much they’ve changed in just the last 5-10 years.
Biomedicine also does not stand still.
Here are some factors that contributed to the rapid emergence of vaccines against COVID-19
Classic vaccines usually use a weakened version of the virus or its protein part. The virus multiplies (and large amounts of virus are needed to make a vaccine) in chicken embryos or cell cultures and lasts for a long time. In contrast, the use of only the genetic material for cypress (S protein virus) greatly facilitates the process. mRNA can be easily synthesized in the laboratory. So developing an RNA vaccine instead of a protein or whole virus vaccine saves months, if not years. It can be ready literally in a week, as long as we know exactly which gene or genes we are interested in. The answer to this question also came quickly thanks to the similarity between SARS-CoV-2 and the related virus SARS-CoV-1 (an impressive 82%).
Simultaneous implementation of preclinical and clinical trials or two phases of clinical trials.
Fast and efficient recruitment of volunteers for clinical trials.
Large-scale clinical trials of safety and efficacy are being conducted simultaneously with large-scale preparations for possible production. This is usually done after the completion of clinical trials. However, in the case of COVID-19, the goal is to ensure that the vaccine is ready for distribution as soon as Phase 3 results are known and safety data is analyzed. To achieve this, pharmaceutical companies made risky investments – this became possible with the financial support of institutions and countries. Therefore, if the vaccine in question is approved for emergency use, its production can begin immediately. This in no way means that the criteria are being lowered for any vaccine project to reach the market. Recently it became clear
Previous experience in the development of vaccines of different species and against different infectious agents, including close relatives of SARS-CoV-2, the causative agent of severe acute respiratory syndrome (SARS-CoV-1, which caused an epidemic in 2002-2003), and Middle East respiratory syndrome (MERS -CoV, which appeared in 2012). They served as a dress rehearsal for our encounter with COVID-19;
Mobilization of enormous scientific and financial resources;
Overall progress in the development of biomedical sciences in recent years. As well as the incredible professionalism and dedication of scientists from all over the world, who compete with the virus and time every day.
RNA vaccines have been a dream come true for generations of scientists
Its implementation has been going on for 3 decades. Experimental studies of the possible use of RNA molecules for medical purposes began in the early 1990s. What cools the enthusiasm of scientists is the fragility of RNA molecules, which easily become victims of enzymes contained in the biological environment, and ensuring the necessary very low temperature for their storage is definitely a challenge. Later, the efforts of researchers made it possible to optimize RNA vaccines. Interest is also focused on finding the most suitable carriers of these vaccines, capable of preserving the integrity of the RNA molecule, taking it to the right cells and releasing it there so that it can carry out its tasks. Lipid nanoparticles act as carriers in Pfizer / BioNTech and Moderna vaccines.
The idea is to use RNA vaccines to overcome some of the shortcomings of our well-known vaccines that contain whole virus particles (attenuated / attenuated live vaccines or inactivated vaccines). The advantage of RNA vaccines is that they are produced quickly and easily, since they contain only nucleic acid and not proteins or whole viruses . Their preparation does not involve the participation of cell cultures or the need to grow the virus in chicken embryos. This also has its advantages, one of which is that there is no risk of triggering an allergic attack in people with hypersensitivity to egg white (traces of it could remain in the final product).
Efforts are being made to create RNA vaccines not only against various infectious agents (Ebola and Zika viruses, influenza and rabies), but also against allergies, autoimmune diseases and cancer.
The results of the first phase I/II clinical trial using mRNA molecules in melanoma patients were published in 2008. in the Journal of Immunotherapy. He defines direct mRNA injection as “one of the easiest, most universal and theoretically safest technologies”.
It has been successfully used in the development of other cancer vaccines, which have been tested in numerous clinical trials with promising results to extend the period in which cancer progression is not observed.
In parallel, clinical trials are underway on other mRNA vaccines, including those targeting different infectious agents. Some of them are described in a review devoted to this topic by the journal Nature Reviews Drug Discovery. The article appeared on the 12th. January 2018 with the inspiring title “mRNA vaccines – a new era in vaccinology”.
Moreover, scientists see in mRNA not only the possibility of a vaccine, but also a therapeutic approach. For this purpose, antibody genes are generated that encode mRNA that neutralizes the respective pathogen.
In summary, long before the COVID-19 pandemic, it became clear that mRNA vaccines have enormous potential and offer numerous advantages over conventional vaccines, promising a new platform that is flexible and easy to update, as well as rapid, widespread and inexpensive production, without the risks associated with the handling of infectious material. They asked to be able to respond in a timely manner to new devastating infectious diseases. As it happened.
A large number of preclinical and clinical studies have shown that mRNA vaccines are safe and well tolerated in animal models and humans.
It was the mRNA vaccines that were the first to receive an emergency/conditional license against COVID -19 – products from the companies Pfizer/BioNTech and Moderna.
Security
Tens of thousands of volunteers have participated in clinical trials of vaccines against COVID-19, far exceeding the number of participants in vaccine trials known to us for years. However long they last, there is no way they can bring to light events that occur less often than 1 in 3,000 or 1 in 5,000 people.
The side effects we have learned about are:
- Allergies to the components of the vaccine (frequency of several cases per million vaccinated) – the presence of such a vaccine is the only indicated contraindication for its use;
- Blood clotting problems with adenoviral vectors containing vaccines – mainly in women under 60 years of age up to two weeks (5 to 16 days) after the first dose of the AstraZeneca vaccine and up to 3 weeks with Johnson & Johnson / Janssen;
- Myocarditis and pericarditis in the Pfizer / BioNTech and Moderna mRNA vaccines. According to the European Medicines Agency (EMA) and the WHO, they are observed mainly in men, and their frequency is higher in those under 30 years of age. Symptoms usually develop within a few days (up to 14) after receiving the second dose of the vaccine. The largest safety study of the Pfizer / BioNTech vaccine, involving nearly two million people in Israel, found that the most serious reaction to this vaccine was myocarditis. 2.7 (1 to 5) cases of myocarditis per 100,000 vaccine doses have been reported. At the same time, 11 cases of myocarditis were registered per 100,000 unvaccinated people who were infected with SARS-CoV-2. The data was published on the 25th. August 2021 in The New England Journal of Medicine.
It is important to note that pericarditis, cardiac arrhythmias, heart attacks, stroke, pulmonary embolism, deep vein thrombosis, acute kidney injury, etc. Also reported in people who have not been vaccinated and infected with the virus. The side effects of the two groups of vaccines – RNA vaccines and those containing adenoviral vectors – do not overlap.
August 23, 2021 In 2018, Pfizer/BioNTech’s Comirnati vaccine became the first COVID-19 vaccine to be fully approved by the US Food and Drug Administration (FDA) for use in people 16 years of age and older. Thus, it became a full member of the family of vaccines that we have known and used for years.
