Abstract

Introduction: According to the results of our previous study, the presence of representatives of pathogenic microflora in the secretion of the oropharynx significantly increased in patients with chronic inflammatory diseases of the upper respiratory tract (URT), vaccinated against COVID-19, who contracted this viral disease, which created favourable conditions both for deterioration of the course of the disease (CID of URT) and for reduction of their general antiviral protection in such patients.

The purpose of the study: to find out the feasibility of supplementing the vaccination of patients with chronic obstructive pulmonary disease against COVID-19 by taking an immunotropic agent of bacterial origin.

Materials and methods: A total of 45 patients with chronic inflammatory diseases of URT were examined, who were divided into 3 groups. The 1^st group included patients who did not suffer from COVID-19 and were not vaccinated against this disease. The 2^nd and 3^rd groups were made up of patients with chronic inflammatory diseases of URT, who were vaccinated against this disease and who after that either did not get sick with COVID-19 (2^nd group), or still suffered this disease (3^rd group). All of them were prescribed a lyophilized lysate of bacteria that often cause infectious diseases of the urinary tract (OM-85) in accordance with the instructions for its use. Examination, survey and immunological examination for the presence of G-class antibodies to Ns S-antigens of the coronavirus (ELISA, Diaprof, Ukraine) of all patients were carried out at the beginning of the study, as well as 6 months after they received the mucosal vaccine. The reliability of the differences of the obtained results was evaluated using the one-sided Fisher’s exact method (EFT). The difference between the obtained data with pEFT <0.05 was considered reliable.

Results and discussion: Based on the observations made, it can be stated that the patients of all three experimental groups had contact with the SARS-CoV-2 virus, although only the third group recorded clinical manifestations of the disease caused by it.
When analysing the course of the main disease in patients with chronic inflammatory diseases of URT, the number of registered disease recurrences was chosen as an objective criterion. On the one hand, the assessment was carried out based on the difference in the frequency of exacerbations during the observation period separately in each experimental group before and after mucosal vaccination. On the other hand, by the number of patients with a different number of relapses before and after taking OM-85. As a result, no significant differences were found in terms of the number of exacerbations of chronic inflammatory diseases of URT among patients of all three experimental groups before and after taking OM-85. However, if before vaccination all patients of the I group noted relapses of chronic inflammatory diseases of URT within a year, then after it they were found in only 9 people (pEFT<0.01). The number of exacerbations in individual patients also decreased – in no case were they observed in the number of 5 or more.
Similar shifts took place in the 2^nd group. The number of patients who noted relapses of the main disease after mucosal vaccination decreased from 15 to 8 (pEFT<0.01). At the same time, if before taking OM-85 the majority of patients – 10 out of 15 – had 3-4 episodes of exacerbation of the main disease per year, after mucosal vaccination their number decreased to 5. In addition, no patient had 5 or more exacerbations for a year.
However, the most significant changes caused by OM-85 occurred in the 3^rd group, where the number of patients who had relapses of chronic inflammatory diseases of URT fell by 2/3 – in 10 patients, no exacerbations of the main disease were observed at all (pEFT<0.001).
Thus, it can be asserted that mucosal vaccination of patients with chronic inflammatory diseases of URT helps to improve the course of their underlying disease even against the background of vaccination against COVID-19 and transmission of this disease.
The frequency of detection of acute respiratory viral infections in them before and after taking OM-85 was chosen as a criterion for the ability of the examined contingent of persons to counteract external infectious factors. In addition, in relation to viral infections, the administration of the mucosal vaccine to patients with chronic inflammatory diseases of URT also showed a pronounced protective effect, regardless of their vaccination against COVID-19 and the transferred disease caused by SARS-CoV-2.
Such a result indicates the preservation of a certain functional reserve in such patients to counteract both the negative manifestations of their underlying disease and external factors of viral origin.
According to the results of clinical observations, the appointment of immunotropic drug OM-85 of bacterial origin to patients with chronic inflammatory diseases of the upper respiratory tract, vaccinated against COVID-19, improves the course of their main otolaryngological disease and reduces the number of acute respiratory viral infections.

Key words: upper respiratory tract, chronic inflammatory diseases, SARS-CoV-2, COVID-19, acute respiratory viral infections, mucosal vaccine OM-85.