ABSTRACT
In December 2019, an acute respiratory disease outbreak from zoonotic origin was detected in the city of Wuhan, China. The outbreak's infectious agent was a type of coronavirus never seen. Thenceforth, the Covid-19 disease has rapidly spread to more than 200 countries around the world. To minimize the devastating effects of the virus, the States have adopted epidemiological measures of various kinds that involved enormous economic expenses and the massive use of the media to explain the measures to the entire population. For the prediction and mitigation of infectious events, various epidemiological models, such as SIR, SEIR, MSIR and MSEIR, are used. Among them, the most widely used is the SIR model, which is based on the analysis of the transition of individuals susceptible to infection (S) to the state of infected individuals that infect (I) and, finally, to that of recovered (cured or deceased) (R), by using differential equations. The objective of this article was the mathematical development of the SIR model and its application to predict the course of the Covid-19 pandemic in the city of Santa Marta (Colombia), in order to understand the reason behind several of the measures of containment adopted by the States of the world in the fight against the pandemic.
ABSTRACT
Introduction: The COVID-19 pandemic has represented an unprecedented health, economic and social catastrophe for the present generations. Despite health efforts, no effective pharmacological treatment is known, so biosecurity measures and vaccines are the main containment measures. Objective: Describe the immunovirological and clinical characteristics of four of the main vaccines available in Colombia. Methods: A bibliographic search of documents published in the period 2020-2021 was carried out. Keywords such as "DNA and RNA" vaccines were used;"COVID vaccines";"COVID-19", "SARS-CoV-2" for the recovery of documents in databases such as SciELO, PubMed, Science Direct, among others. Results: Pfizer and Moderna are mRNA vaccines with a 2-dose schedule and a third booster;the first with an effectiveness of 95%, the second between 82% and 95% depending on the age group. Some side effects of both vaccines can become myocarditis and pericarditis. AstraZeneca is a non-replicative viral vector vaccine, with 69% effectiveness and a two-dose schedule, with a possible booster. Some adverse effects reported are thromboembolic diseases, Guillain-Barré and transverse myelitis. CoronaVac is an inactivated SARS-CoV2 vaccine, with 54% effectiveness and 100% prevention of hospitalizations, and it is the newest of the vaccines developed and may present the same adverse effects as the previous ones. Specific contraindications were found for no vaccine. In Colombia, the most applied are Pfizer, AstraZeneca and Moderna. Conclusions: Several vaccines against COVID-19 have been developed with different mechanisms of action. No absolute contraindications are reported that justify not being vaccinated;on the contrary, vaccination is the most promising bet to end the pandemic. It is necessary to promote strategies that increase the vaccination rate, especially in reluctant population groups.