ABSTRACT
Until the approval of vaccines at the end of 2020, societies relied on non-pharmaceutical interventions (NPIs) in order to control the COVID-19 pandemic. Spontaneous changes in individual behavior might have contributed to or counteracted epidemic control due to NPIs. For example, the population compliance to NPIs may have varied over time as people developed 'epidemic fatigue' or altered their perception of the risk and severity of COVID-19. Whereas official measures are well documented, the behavioral response of the citizens is harder to capture. We propose a mathematical model of the societal response, taking into account three main effects: the citizen response dynamics, the authorities' NPIs, and the occurrence of unpreventable events that significantly alter the virus transmission rate. A key assumption is that a society has a waning memory of the epidemic effects, which reflects on both the severity of the authorities' NPIs and on the citizens' compliance to the prescribed rules. This, in turn, feeds back onto the transmission rate of the disease, such that a higher number of hospitalizations decreases the probability of transmission. We show that the model is able to reproduce the COVID-19 dynamics in terms of hospital admissions for several European countries during 2020 over surprisingly long time scales. Also, it is capable of capturing the effects of disturbances (for example the emergence of new virus variants) and can be exploited for implementing control actions to limit such effects. A possible application, illustrated in this letter, consists of exploiting the estimations based on the data of one country, to predict and control the evolution in another country, where the virus spreading is still in an earlier phase. © 2017 IEEE.
ABSTRACT
Until the approval of vaccines at the end of 2020, societies relied on non-pharmaceutical interventions (NPIs) in order to control the COVID-19 pandemic. Spontaneous changes in individual behavior might have contributed to or counteracted epidemic control due to NPIs. For example, the population compliance to NPIs may have varied over time as people developed “epidemic fatigue" or altered their perception of the risk and severity of COVID-19. Whereas official measures are well documented, the behavioral response of the citizens is harder to capture. We propose a mathematical model of the societal response, taking into account three main effects: the citizen response dynamics, the authorities’NPIs, and the occurrence of unpreventable events that significantly alter the virus transmission rate. A key assumption is that a society has a waning memory of the epidemic effects, which reflects on both the severity of the authorities’NPIs and on the citizens’compliance to the prescribed rules. This, in turn, feeds back onto the transmission rate of the disease, such that a higher number of hospitalizations decreases the probability of transmission. We show that the model is able to reproduce the COVID-19 dynamics in terms of hospital admissions for several European countries during 2020 over surprisingly long time scales. Also, it is capable of capturing the effects of disturbances (for example the emergence of new virus variants) and can be exploited for implementing control actions to limit such effects. A possible application, illustrated in the paper, consists of exploiting the estimations based on the data of one country, to predict and control the evolution in another country, where the virus spreading is still in an earlier phase. IEEE
ABSTRACT
Objective: We aimed to assess whether SARS-CoV2 vaccines have any positive or negative impact on motor symptoms in PD patients. Background: Studies focusing on the relationship between SARSCoV- 2, COVID-19 and PD have provided conflicting results (1). Recently, few cases of severe dyskinesia after receiving BNT162b2 mRNA vaccine have been reported but there is no data about impact of vaccines on motor symptoms in larger series of PD patients (2). Methods: We reviewed the charts of the last two months of consecutive PD patients who were attended monthly by telemedicine during the pandemic and who had received one or two doses of any of the SARSCoV- 2 vaccines available in Peru (BNT162b2, Pfizer/BioNTech and BBIBP-CorV, Sinopharm). We specifically searched for any reported variation on motor symptoms including dyskinesia during a period of at least three days after any of each dose. Results: One hundred eighty-one PD patients met inclusion criteria. 107 males and 74 females were included. Mean age was 65 years old (range 31-99). 178 patients received two doses of SARSCoV2 vaccine (177 Pfizer/BioNTech and 1 Sinopharm respectively) and three patients received only one dose of Pfizer/BioNTech vaccine. Eleven patients (6%) had COVID19 infection during the pandemic. The effect of the infection on parkinsonian symptoms was not evaluated in this report. Only two patients (1.1%) reported some degree of exacerbation following one of the dose of the vaccine. First one presented with increased rigidity and gait impairment soon after the first dose and the second case presented with increased resting tremor that lasted for two weeks also after the first dose. In both cases exacerbation improved spontaneously. Conclusion: The approved mRNA-based vaccines and viral vector vaccines are not expected to interact with the neurodegenerative process nor modify motor symptoms in PD. SARS-CoV-2 vaccines are not known neither to interfere with the current therapies for PD. Some patients have developed exacerbation of motor symptoms or severe dyskinesia after vaccination and the reasons remain unclear but they might be explained by triggering a systemic inflammatory response, by stress or excessive anxiety or due to modification of habitual medication response. These very low incidence should not discourage patients to receive vaccines and we recommend COVID-19 vaccination with approved vaccines for persons with PD, unless there is a specific contraindication.