An issue of undoubted general interest is to try to predict SARS-CoV-2 future evolution. In this regard, an article was published on 13 November 2020 in Science, which rigorously addresses this subject. It states, among other things, that this will in part depend on possible variations in the immune response following SARS-CoV-2 infection and the subsequent vaccination and non-pharmaceutical measures taken in the world, especially the closure of businesses and educational centers, movement restrictions, and perimeter closures of the most affected areas.
SARS-CoV-2 future evolution
Likewise, in geographic areas where sudden climate changes can be expected, the mathematical models used predict a reduction in susceptibility to secondary infections or a longer duration of acquired immunity, which may prevent a new peak in the epidemic. These effects will be reduced in regions where climate fluctuations are smaller. In general, however, the analytical model used suggests that climate can significantly influence the prevalence of infections.
Undoubtedly, the evolution of the pandemic will also be conditioned by the number of vaccinations, although this, in turn, will be conditioned by the effectiveness of the vaccine and the nature of the immune response. Nevertheless, the analysis shows that, regardless of the national immunity achieved and even with moderate vaccination rates, vaccination can accelerate control of the pandemic.
Cellular immunity, in parallel with the number of tests performed, will also determine the overall immunity achieved.
Specifically, the study indicates three determinants of the evolution of the pandemic in the future:
- on the duration and strength of the measures taken to block transmission, and on the clinical immunity obtained after the first wave of infections and mass vaccination;
- individual and population variations in various parameters, especially the age of citizens; and
- the impact of viral evolution, possible coinfections and other characteristics of Covid-19.
The authors conclude that “accurately characterizing the individual immune life histories and the cumulative immune landscape of the population to SARS-CoV primary and secondary infection and vaccination will be critical for the management and control of the ongoing pandemic”.