Publication date: Aug 01, 2024
The SARS-CoV-2 pandemic has generated a considerable number of infections and associated morbidity and mortality across the world. Recovery from these infections, combined with the onset of large-scale vaccination, have led to rapidly-changing population-level immunological landscapes. In turn, these complexities have highlighted a number of important unknowns related to the breadth and strength of immunity following recovery or vaccination. Using simple mathematical models, we investigate the medium-term impacts of waning immunity against severe disease on immuno-epidemiological dynamics. We find that uncertainties in the duration of severity-blocking immunity (imparted by either infection or vaccination) can lead to a large range of medium-term population-level outcomes (i. e. infection characteristics and immune landscapes). Furthermore, we show that epidemiological dynamics are sensitive to the strength and duration of underlying host immune responses; this implies that determining infection levels from hospitalizations requires accurate estimates of these immune parameters. More durable vaccines both reduce these uncertainties and alleviate the burden of SARS-CoV-2 in pessimistic outcomes. However, heterogeneity in vaccine uptake drastically changes immune landscapes toward larger fractions of individuals with waned severity-blocking immunity. In particular, if hesitancy is substantial, more robust vaccines have almost no effects on population-level immuno-epidemiology, even if vaccination rates are compensatorily high among vaccine-adopters. This pessimistic scenario for vaccination heterogeneity arises because those few individuals that are vaccine-adopters are so readily re-vaccinated that the duration of vaccinal immunity has no appreciable consequences on their immune status. Furthermore, we find that this effect is heightened if vaccine-hesitants have increased transmissibility (e. g. due to riskier behavior). Overall, our results illustrate the necessity to characterize both transmission-blocking and severity-blocking immune time scales. Our findings also underline the importance of developing robust next-generation vaccines with equitable mass vaccine deployment.
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Concepts | Keywords |
---|---|
Mathematical | Computational Biology |
Models | COVID-19 |
Pessimistic | COVID-19 Vaccines |
Rapidly | COVID-19 Vaccines |
Vaccines | Humans |
Pandemics | |
SARS-CoV-2 | |
Vaccination | |
Vaccination Hesitancy |
Semantics
Type | Source | Name |
---|---|---|
disease | VO | vaccine |
disease | MESH | infections |
disease | MESH | morbidity |
disease | VO | vaccination |
disease | VO | population |
disease | IDO | infection |
disease | IDO | host |
disease | VO | vaccinated |
disease | VO | time |
disease | VO | Canada |
disease | MESH | emergency |
drug | DRUGBANK | Cysteamine |
disease | VO | effective |
disease | IDO | susceptibility |
disease | MESH | breakthrough infection |
drug | DRUGBANK | Ilex paraguariensis leaf |
disease | IDO | pathogen |
disease | VO | dose |
disease | MESH | COVID 19 |
disease | MESH | secondary infections |
disease | MESH | death |
disease | VO | vaccination coverage |
disease | VO | Optaflu |
disease | IDO | intervention |
drug | DRUGBANK | Aspartame |
disease | IDO | primary infection |
disease | MESH | reinfection |
disease | VO | transmission blocking vaccine |
drug | DRUGBANK | Coenzyme M |
disease | MESH | Long COVID |
disease | MESH | Infectious diseases |
disease | IDO | history |
disease | IDO | symptom |
disease | MESH | chronic disease |
disease | IDO | infectious disease |
disease | VO | report |