Comparative Analysis of the Spread of the COVID 19 Epidemic in Berlin and New York City Based on a Computational Model

Mairanowski²

2021

Preprint

A modified model of the epidemic under conditions of mass vaccination was developed. A comparison of the model results with statistical observations in Israel shows good agreement.Model calculations are performed on the efficacy of limiting the development of an epidemic by both lockdown and vaccination. Mass vaccination of the population is the most radical method of limiting the growth of the epidemic. The introduction of a lockdown cannot completely prevent the development of an epidemic. The likelihood of the emergence of new strains of the virus is assessed. Without vaccination, the probability of more than two new virus strains per year affecting the epidemic growth process is found to be about 60%. A controlled calculation was made of the effect of the timing of changes in lockdown conditions during the vaccination period on the development of the epidemic. It was particularly shown that the cancellation of the lockdown together with the start of vaccination did not reduce the maximum number of new infections. A controlling calculation was made of the effects of gradually cancelling lockdown. On the basis of these calculations, it is possible to assess the development of the epidemic in different variants of partial lockdown cancellation.Three dimensionless complexes, made up of the intensities of transmission, vaccination and lockdown restrictions, are found to determine the epidemic’s development.The intensity of the coronavirus epidemic depends on climatic characteristics, in particular air temperature and the UV index. A relationship is given to estimate the influence of these factors on infection growth.The way forward for further development of the model is outlined. The immediate goal of modifying the model is to use it for each age group in the population and to find out the links between vaccination rates and the psychological state of the population, i.e. people’s readiness for mass vaccination.

The impact of vaccination on the spread patterns of the COVID epidemic

Mairanowski²

2021

Preprint

Functional dependence of COVID-19 growth rate on lockdown conditions and rate of vaccination

Mairanowski¹,

2021

Preprint

It is shown that derived from the solution of differential equations analytical model adequately describes development epidemics with changes in both lockdown conditions and the effective rate of mass vaccination of the population. As in previous studies, the control calculations are in good agreement with observations at all stages of epidemic growth. One of the two model coefficients is uniquely related to the lockdown efficiency parameter. We obtained an approximate correlation between this parameter and the main conditions of lockdown, in particular, physical distancing, reduction in social contacts and strictness of the mask regime. The calculation of the incident over a seven-day period using the proposed model is in good agreement with the observational data. Analysis of both curves shows that a better agreement can be obtained by taking into account the lag time of the epidemic response of about 10 days. From the reverse calculation a time-varying curve of the infection rate associated with the "new" virus strain under mutation conditions is obtained, which is qualitatively confirmed by the sequencing data. Based on these studies, it is possible to conclude that the ASILV analytical model developed here can be used to reliably and promptly predict epidemic development under conditions of lockdown and mass vaccination without the use of numerical methods. The functional relationships identified allow us to conduct a rapid analysis of the impact of each of the model parameters on the overall process of the epidemic. In contrast to previous studies, the calculations of the proposed model were performed using EXCEL, rather than a standard calculator. This is due to the need to account for multiple changes in lockdown conditions and vaccination rates.

The age-stratified analytical model for the spread of the COVID-19 epidemic

Mairanowski¹,

2021

Preprint

The previously developed ASILV model for calculating epidemic spread under conditions of lockdown and mass vaccination was modified to analyse the intensity of COVID-19 infection growth in the allocated age groups. Comparison of the results of calculations of the epidemic spread, as well as the values of the seven-day incidence values with the corresponding observation data, shows their good correspondence for each of the selected age groups. The greatest influence on the overall spread of the epidemic is in the 20-40 age groups. The relatively low level of vaccination and the high intensity of contact in these age groups contributes to the emergence of new waves of the epidemic, which is especially active when the virus mutates and the lockdown conditions are relaxed. The intensity of the epidemic in the 90+ age group has some peculiarities compared to other groups, which may be explained by differences in contact patterns among individuals in this age group compared to others. Approximate ratios for estimating mortality as a function of the intensity of infection for individual age groups are provided. The proposed stratified ASILV model by age group will allow more detailed and accurate prediction of the spread of the COVID-19 epidemic, including when new, more transmissible versions of the virus mutate and emerge.