Estimation of COVID-19 risk-stratified epidemiological parameters and policy implications for Los Angeles County through an integrated risk and stochastic epidemiological model

Coronavirus new variants: the mutations cause and the effect on the treatment and vaccination

Background: The world has watched with growing alarm as scientists in the U.K.  Identified a new coronavirus variant that appears to be more contagious than, and genetically distinct from, other established variants. The scientists keep collecting the facts about the new variant and its impact on symptom, severity, mortality, and vaccine efficacy. Objective: This review shed light on the SARS-CoV-2 2020 virus that appeared in Britain and South Africa in December 2020, known as B.1.1.7. Furthermore, it highlights the main differences between the new COVID-19 version (B.1.1.7) and the other strains of the virus. Conclusion: Mutations are still happening in the SARS-CoV-2 virus as the RNA viruses cause many changes in the proteins of the spikes of the virus and other parts. The British variant has 23 mutations, compared with the version that erupted in Wuhan, that renders the virus more contagious; however, these mutations do not change the disease's severity.

Los Angeles County SARS-CoV-2 Epidemic: Critical Role of Multi-generational Intra-household Transmission

We observed wide variation in the incidence of confirmed COVID-19 cases in 300 communities making up Los Angeles County, the largest county by population in the United States. The surge in incidence from October 19, 2020 to January 10, 2021, accounting for two-thirds of all confirmed cases since the start of the epidemic, was concentrated in communities with a high prevalence of multi-generational households. This indicator of household structure was a more important predictor of the surge in incidence than the prevalence of households with low income or with at least one high-risk worker. Based upon a spatial adaptation of the standard SIR model, the cumulative incidence of COVID-19, adjusted for underascertainment of both asymptomatic and symptomatic cases, ranged from under 10% in low multi-generational communities to over 30% in high multi-generational communities.