For the past two years, the National Poll initiative has been monitoring the development of the COVID-19 epidemic in Belarus. Through a series of regular surveys, the main topics of which were completely unrelated to the coronavirus (thus removing participation bias), the answers of 7,302 unique respondents were collected. Multilevel regression models with poststratification were then applied to these data to generalize the results both to the entire adult population of the country and to obtain estimates for specific subgroups. Below, we publish the final estimates obtained based on data from all the surveys.
We shall start the report with good news! Since March 2022 there has been a sharp decline in incidence rates. The anticipated autumn rise was also much smaller than the peaks of previous seasons and was comparable to the incidence of summer 2020 and 2021. In September 2022, the average number of those officially diagnosed, according to our estimates, was most likely 2009 people daily (95% credible interval from 1366 to 2832). If we additionally consider those who lost the sense of taste or smell, the estimates become 3,642 people (95% credible interval from 2,579 to 4,912) respectively. However, it should be noted that the new strains of SARS-CoV-2 (omicrons) are much less likely to cause the loss of taste or smell.
Also, the level of possible herd immunity in the population has most likely reached 70% (95% credible interval from 62% to 76%) according to our estimates. These estimates consider those who are fully or partially vaccinated, as well as those who have had the disease or believe they have had the disease and lost the sense of smell or taste.
Our estimates allow us to express a cautious opinion about the transition of COVID-19 from a pandemic to a seasonal endemic disease. That is, it can be expected that different strains will determine seasonal peaks, including their possible transition in certain periods to the local epidemics, just as happens with the flu. Hence, we are stopping the monitoring of COVID-19 for a time being. Nevertheless, we reserve the right to return to it if the epidemic situation becomes difficult again.
According to the obtained estimates, the share of those who had COVID-19 or believe they were infected (and lost their sense of smell or taste) with a 95% probability is between 52% and 63% of adult residents of Belarus with a posterior mode of 58%. Officially diagnosed with COVID-19 at least once were 43% (95% credible interval 37% to 49%) of the adult population. According to official data, the share of those who were infected with COVID-19 in Belarus is about 10%. According to our estimates, this is lower than the actual number of diagnoses made in Belarus, with a probability of at least 99.9%. It is also interesting that a significant share of those who got infected after March 2022 was already having the COVID 19 not for the first time. Overall, 27% (95% CI 21% to 33%) of adults with a formal diagnosis were most likely to have had the disease more than once. And the posterior mode for the time interval between illnesses for those who got sick twice was most likely 10.6 months (95% credible interval from 9.3 to 11.8 months).
As for vaccination, its two peaks occurred in July and October 2021, when 15,147 (95% credible interval from 11,909 to 19,125) and 13,480 (95% credible interval from 10,562 to 17,080) people were most likely getting vaccinated daily, respectively.
We found a significant decrease in the number of vaccinated people already in November 2021, and while the actual rate of vaccination began to fall, the officially reported by the authorities one continued to increase. Overreporting likely ended in July 2022. In general, according to our estimates, the official data of the Ministry of Health regarding vaccination are statistically significantly deviant from the estimated actual levels. At the time of our last survey (10/20/2022), 30% (95% credible interval 24% to 37%) of the adult population were most likely fully vaccinated. 34% were at least partially vaccinated (95% credible interval 28% to 41%). Officially, 70.2% of the population completed the full course of vaccination, and 71.4% completed at least a partial course as of the end of October 2022. The Ministry of Health data lie outside even the 99.9% credible intervals for the relevant parameters and seem abnormally high.
Vaccination against COVID-19 was very effective in protecting older age groups from admission to the hospital or intensive care unit and reduced the corresponding risks. For instance, for the unvaccinated population of the age group of 60+, the most likely values of the risk of hospitalization and intensive care were 24.7% and 5.3%, respectively, while for the fully vaccinated, they were most likely reduced to 3.6% and 1.7%! Hence, we still highly recommend vaccinations for vulnerable populations.
Graphs with the most significant estimates are available at the link.