Need to quickly develop vaccine against SARS-CoV-2 is the share of a growth period of basic knowledge, including such areas as genomics and structural biology that provides scientific support of a new era in vaccine creation. For the last decade the task of quick response in response to H1N1 flu epidemics, fevers Ebola and Zika diseases, and now — the SARS-CoV-2 virus was repeatedly set for the scientific community and the enterprises developing vaccines.
The companies on production of vaccines and the biotechnology companies with assistance of other financing organizations invest considerable means in realization of such approaches. Multiple platforms are now developed for creation of vaccines. The platforms based on DNA and RNA have the largest high-speed potential they are followed by platforms for development of recombinant and subunit vaccines. RNA - and DNA-vaccines can be created quickly as their development does not demand cultivation or fermentations, instead are used synthesizing processes. Existence at developers and regulators of experience of use of such platforms for creation of the personalized vaccines against oncological diseases can simplify the procedure of fast testing of vaccines and their release. At the moment yet there are no approved RNA-vaccines, but their clinical tests are already begun and regulators have an experience of assessment of examples of use of vaccines in clinical tests and also in their subsequent production. Use of methods of sequenation of new generation and reverse genetics can also reduce time necessary for development of more usual types of vaccines in the period of epidemic.
But even when using new platforms development of vaccine against SARS-CoV-2 is accompanied by certain difficulties.
First, in spite of the fact that aculeiform protein of a coronavirus is perspective immunogen for ensuring protection, to crucially optimize structure of antigen to achieve an optimum immune response. Discussions concerning what technique it is better to choose — for example are still conducted, to target full-size protein or only the receptor-binding domain.
Secondly, preclinical tests of samples of vaccine for SARS and the Middle Eastern respiratory syndrome (MERS) caused concerns about aggravation of a clinical picture of a pulmonary disease — directly or as a result of antitelozavisimy strengthening. Such failure can be associated with answer T-helperov 2 types (Th2). From this it follows that testing on suitable model with use of animals and careful control of safety when carrying out clinical tests will have crucial value. If the call of the sufficient answer of a system of immunity or for reduction of a dosage requires adjuvants, then it is more probable that theoretically more capable to ensuring protection and to prevention of risk of development of immunopathological processes will be adjuvants which provoke the answer of Th1 and show the pronounced neutralized humoral answer. Nevertheless data and the detailed overview on this subject are necessary.
Thirdly, in spite of the fact that correlates of protection can be removed on the basis of experience of use of vaccines against SARS and MERS, they still are up to the end not established. As well as in a case with the infection acquired in the natural way, the potential duration of immunity is unknown; also not clearly, whether one-dose vaccine will help to develop immunity.
It is necessary to understand that development of vaccine is a long, expensive process. The coefficient of elimination of participants from an experiment is high and to receive the licensed vaccine at the exit, participation of a large number of candidates usually is required. In view of the high cost and frequency of unsuccessful experiments developers usually carry out a number of the consecutive steps alternating numerous breaks on the analysis of data or check of process of production. Fast development of vaccine demands a new pandemic paradigm of which quick start and simultaneous performance of several actions even before confirmation of a successful outcome of the previous stage of work is characteristic that leads to increase in financial risks. For example, during the work on platforms with experience of participation of people clinical tests of the first phase can be carried out along with testing with use of experimental models of animals. The pandemic paradigm demands simultaneous performance of several tasks with financial risks which arise before developers and producers in those conditions when they do not know whether there will be a vaccine safe and effective; here belong expansion of the output to commercial scales at very early stages, even before receiving exact clinical confirmation of the concept.