## Introduction

COVID-19 is an infectious viral high-contagious disease with predominant damage to lung tissue. Pathognomonic clinical signs are respiratory failure and distress syndrome (Cennimo, 2020). In addition to these symptoms, patients complain about a dry cough, fever, and weakness. Although the first wave of coronavirus is already behind and the second wave is only gaining momentum, the whole world is especially hopeful for the rapid development of a vaccine that will significantly slow down the rate of spread of COVID-19. Thus, the analysis and evaluation of the progress of laboratory development of vaccines against this disease is a priority task with high social and medical value. This work investigates the phenomenon of vaccine development in the context of a coronavirus pandemic and discusses the progress already achieved.

## Ways of Transmission

The transmission mechanism is called the method of moving an infectious agent from an infected organism to a susceptible organism in which infection occurs. The SARS-CoV-2 destroys the patient’s respiratory tract, mainly by localizing in the lungs, but there may be several pathways for the pathogen to enter the human body: the airborne and the dust pathways and the contact one (Cennimo, 2020). At the same time, after the end of the incubation period — which usually lasts about a week — a person does not necessarily begin to show symptomatic signs. In this case, the disease may be mild, and it follows that asymptomatic transmission can be claimed.

It is important to note that the extent of the pathogen’s spread can be estimated using some of the mathematical models, among which the SIR model and the model of variations should be highlighted. Using equation (Eq. 1), the researchers define the number of infected people in a closed population as a function of time. This formula provides preliminary information on the progression of COVID-19, although the interpretation of the results should be careful, as the formula requires some assumptions. The logical development of this model is the SIR variation: SEIR (Eq. 2), SIS (Eq. 3). Although these formulas derive from a common SIR model, they are very different from each other. For example, SEIR is used for truly dangerous epidemics with long incubation periods, while SIS is applicable for diseases that do not produce immunity: seasonal influenza or ODS.

To curb the pandemic’s spread, many states resort to radical measures, including full quarantine of the population. This allows limiting the number of social contacts and greatly relieves overcrowded medical clinics. A more rapid approach may be to track contacts, for example, using a mobile application (Sainz, 2020). This mechanism allows to assess of whether there are potential patients in the circle of human communication and thus provide preventive diagnostics.

## Covid-19 Effects

The virus disease and the policy of response have significantly changed the life of humanity, showing the need for self-isolation, masks, and gloves, and social distance. For this reason, it is not a mistake to say that the lives of all age groups and ethnic groups have undergone significant changes. However, this effect is particularly noticeable for representatives of the vulnerable group: it concerns diabetes mellitus, hypertension, heart failure, and concomitant lower respiratory tract diseases (Diabetes, 2020). However, such effects are unlikely to have a long-term effect, as it is expected that early vaccine development will be able to prevent the development of the fourth and third waves of coronavirus. Thus, it can be assumed that within the next few years, COVID-19 will no longer be a problem on a planetary scale and will be among the controlled diseases.

## Covid-19 Vaccination

The mechanism of mRNA of vaccines is reduced to creating artificial immunity by injection of genetic molecules SARS-CoV-2 into the body. The main advantages of such vaccines are their mRNA:

1. rapid degradation in the body after use,
2. relative ease of development,
3. they do not require significant financial costs (Mahalingam & Taylor, 2020).

However, these vaccines also have disadvantages:

• they are new, not yet proven vaccines,
• they are likely to cause a weak immune response,
• mRNA may theoretically fit into a patient’s genome.

Typically, mRNA vaccines contain a nucleotide sequence in which the synthesis of this spike protein is encrypted because it forms an enzymatic compound with the cell receptors, allowing the virus genome to penetrate the cytoplasm. In the short term, after the injection, the patient’s body enhances the immune response as it tries to fight the alien genome. However, this mRNA is not sufficient for the complete synthesis of SARS-CoV-2, so the immune system fights the synthesized spike proteins (“Immune responses,” 2020). Immunization allows the growth of stable antibodies in patients, demonstrating the body’s immunity to coronavirus infection. It should be understood that any vaccines are designed to infect the body with a pathogen easily, so even after mRNA vaccination, some symptoms of the disease are possible: it is a quite natural process (Wadman, 2020). For example, fever, fever, fatigue, muscle pain, and headache may be possible.

mRNA coronavirus vaccines should be made available to as many consumers as possible. According to manufacturers, genome vaccines should be stored in a cold room for thirty years, after which the natural denaturation of components begins (Moderna, 2020). This shelf life may be enough to transport the vaccine anywhere globally and provide the vaccine to anyone who wants it.

## Planning for Future Pandemics

Some results can already be summarized to prevent new pandemics in the future. This may involve building a stock of personal protective equipment in short supply in 2020: masks and gloves. In addition, governments should provide centralized support to the population, ensuring equality of all actors, rather than creating an environment for state competition, as was the case in the United States. It is also worth continuing to develop cross-disciplinary integrations of specialists that were created to find effective political and medical solutions to the virus (“The best time,” 2020). Finally, policymakers should strengthen the development of protocols used in future epidemics in such a way that countries do not face serious financial constraints and that citizens and clinical organizations are willing.

Although the new sanitary rules have changed people’s lives, from the mandatory wearing of a mask to distance learning, one can expect a return to normal life soon. This projected layout includes the immediate removal of quarantine measures, public facilities’ opening, and a return to offline work (Ghosh, 2020). In time, national borders will be opened and travel restored. Simultaneously, the natural cycle of people’s social life will be revived, and the number of contacts will return to the same value.

## Conclusion

So, the pandemic of 2020 had a serious impact on public life, changing the usual order of billions of people. The development of a vaccine becomes a solution that will create immunity for citizens and gradually bring the world back to normal. That is why it is so important to continue studying and analyzing the various vaccine technologies offered today. Although coronavirus infection has caused significant historical events and deaths of one and a half million people, it has also shown the ineffectiveness of existing health systems. Thus, the lessons learned can help governments to withstand future pandemics.

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