Immune life history, vaccination, and the dynamics of SARS CoV 2 over the next 5 years
Imperfect future immunity Humans are infected by several seasonal and cross reacting coronaviruses. None provokes fully protective immunity, and repeat infections are the norm. Vaccines tend to be less efficient than natural infections at provoking immunity, and there are risks of adverse cross reactions. Saad Roy et al. used a series of simple models for a variety of immune scenarios to envisage immunological futures for severe acute respiratory syndrome coronavirus 2 (SARS CoV 2) with and without vaccines. The model outcomes show that our imperfect knowledge about the imperfect coronavirus immune landscape can give rise to diverging scenarios ranging from recurring severe epidemics to elimination. It is critical that we accurately characterize immune responses to SARS CoV 2 for translation into managing disease control. Science, this issue p. 811 Modeling shows how essential it is to improve precise understanding of immune responses to SARS CoV 2. The future trajectory of the coronavirus disease 2019 (COVID 19) pandemic hinges on the dynamics of adaptive immunity against severe acute respiratory syndrome coronavirus 2 (SARS CoV 2) however, salient features of the immune response elicited by natural infection or vaccination are still uncertain. We use simple epidemiological models to explore estimates for the magnitude and timing of future COVID 19 cases, given different assumptions regarding the protective efficacy and duration of the adaptive immune response to SARS CoV 2, as well as its interaction with vaccines and nonpharmaceutical interventions. We find that variations in the immune response to primary SARS CoV 2 infections and a potential vaccine can lead to markedly different immune landscapes and burdens of critically severe cases, ranging from sustained epidemics to near elimination. Our findings illustrate likely complexities in future COVID 19 dynamics and highlight the importance of immunological characterization beyond the measurement of active infections for adequately projecting the immune landscape generated by SARS CoV 2 infections.
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