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

Abstract

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.

Prediction of the next major outbreak of COVID-19 in Mainland China and a vaccination strategy for it

“…10: 230655 through exponential functions [16,17] and, by fitting functions to the actual data, the functional expressions of an immune-waning rate that conforms to the reality are included. Compared to most studies where it is directly taken as a constant [33][34][35][36][37][38], the setting in this paper is more realistic. In addition, other function forms involved in this paper, such as the vaccine coverage rate function and the initial value function of vaccination, are fitted with the actual data to obtain the corresponding function expression, which is the highlight of this paper that is different from other similar studies [27][28][29][30][31][32].…”