Manuel Adrian Acuña-Zegarra

• Phd
• University of Sonora

Many studies have shown that vaccines are not completely effective, meaning that a vaccinated population includes both people who develop immunity from the vaccine and those who, despite being vaccinated, do not. This can be problematic, as some vaccinated individuals may mistakenly believe they are fully protected and cannot acquire the disease. T...

The COVID-19 pandemic has left many open questions for decision-makers. One of them is knowing the counter-factual effect that the implementation of different mitigation strategies to the ones actually used could have caused. This knowledge would allow to contemplate alternative strategies to deal with future infectious disease emergency. Motivated...

The high morbidity of acute respiratory infections constitutes a crucial global health burden. In particular, for SARS-CoV-2, non-pharmaceutical intervention geared to enforce social distancing policies, vaccination, and treatments will remain an essential part of public health policies to mitigate and control disease outbreaks. However, the implem...

The high morbidity of acute respiratory infections constitutes a crucial global health burden. In particular, for SARS-CoV-2, non-pharmaceutical intervention geared to enforce social distancing policies, vaccination, and treatments will remain an essential part of public health policies to mitigate and control disease outbreaks. However, the implem...

A bstract We model the observed dynamics of COVID-19 in Mexico and Peru and explore the impact of hypothetical non-pharmaceutical interventions applied on key days of civic, religious, or political nature that increased contacts and transmission events. Using as a baseline the observed epidemic curve, we apply hypothetical reductions in the contact...

This work presents a methodology to recreate the observed dynamics of emerging infectious diseases and to generate short-term forecasts for their evolution based on superspreading events occurring on key calendar dates. The method is illustrated by the COVID-19 pandemic dynamics in Mexico and Peru up to January 31, 2022. We also produce scenarios o...

From the beginning of the SARS-CoV-2 pandemic, mathematical models have been developed to describe, predict, and control its evolution. This chapter presents a set of useful mathematical tools to understand the epidemic dynamics. First, to obtain a rough approximation to the magnitude of the epidemic, the basic and effective reproduction numbers ar...

About a year into the pandemic, COVID-19 accumulates more than two million deaths worldwide. Despite non-pharmaceutical interventions as social distance, mask-wearing, and restrictive lockdown, the daily confirmed cases remain growing. Vaccine developments from Pfizer, Moderna, and Gamaleya Institute reach more than 90% efficacy and sustain the vac...

Key high transmission dates for the year 2020 are used to create scenarios to model the evolution of the COVID-19 pandemic in several states of Mexico for 2021. These scenarios are obtained through the estimation of a time-dependent contact rate, where the main assumption is that the dynamic of the disease is heavily determined by the mobility and...

The interaction and possibly interference between viruses infecting a common host population is the problem addressed in this work. We model two viral diseases both of the SIRS type that have similar mechanism of transmission and for which a vaccine exists. The vaccine is characterized by its coverage, induced temporal immunity and efficacy. The po...

We present several mathematical models to analyze the SARS-CoV-2 pandemic that is currently impacting the world population. The chapter starts by introducing epidemiological measurements and models useful to characterize the beginning of the epidemic and to obtain a rough understanding of its magnitude. Specially, we discuss the use and estimation...

Lockdown and social distancing measures have been implemented for many countries to mitigate the impacts of the COVID-19 pandemic and prevent overwhelming of health services. However, success on this strategy depends not only on the timing of its implementation, but also on the relaxation measures adopted within each community. We developed a mathe...

At the date, Europe and part of North America face the second wave of COVID-19, causing more than 1 300 000 deaths worldwide. Humanity lacks successful treatments, and a sustainable solution is an effective vaccine. Pfizer and the Russian Gamaleya Institute report that its vaccines reach more than 90 % efficacy in a recent press release. If third s...

SARS-CoV-2 has now infected 15 million people and produced more than six hundred thousand deaths around the world. Due to high transmission levels, many governments implemented social-distancing and confinement measures with different levels of required compliance to mitigate the COVID-19 epidemic. In several countries, these measures were effectiv...

Lockdown and social distancing measures have been implemented for many countries to mitigate the impacts of the COVID-19 pandemic and prevent overwhelming of health services. However, success on this strategy depends not only on the timing of its implementation, but also on the relaxation measures adopted within each community. At the request of So...

SARS-CoV-2 has now infected 15 million people and produced more than six hundred thousand deaths around the world. Due to high transmission levels, many governments implemented social-distancing measures and confinement with different levels of required compliance to mitigate the COVID-19 epidemic. In several countries, these measures were effectiv...

On 23 and 30 March 2020 the Mexican Federal government implemented social distancing measures to mitigate the COVID-19 epidemic. We use a mathematical model to explore atypical transmission events within the confinement period, triggered by the timing and strength of short time perturbations of social distancing. We show that social distancing meas...

Resumen de trabajos de modelado matemático para las proyecciones de COVID-19 en la CDMX y evaluación de medidas de mitigación. Con datos al 4 de mayo del 2020. Trabajo colectivo de investigadores de la UNAM y colaboradores de otras instituciones.

Sanitary Emergency Measures (SEM) were implemented in Mexico on March 30th, 2020 requiring the suspension of non-essential activities. This action followed a Healthy Distance Sanitary action on March 23rd, 2020. The aim of both measures was to reduce community transmission of COVID-19 in Mexico by lowering the effective contact rate. Using a modif...

We present here several variants of a mathematical model to explore three main issues related to SARS-CoV-2 spread in scenarios similar to those present in Mexico and elsewhere in Latin America. We explore the consequences for travel inside a given region, in this case Mexico, particularly focusing on airplane transportation but attempting to give...

Chagas disease is an important neglected tropical disease which causes on average about 7,000 deaths per year, and an estimated 25 million people risk of acquiring it. This illness is often found in rural areas, which are usually characterized by poverty and presence of animals which act as reservoirs of the disease. Our main objective is to study...

We present a stochastic epidemic model with vectorial transmission and multi-host structure. To include environmental noise, we stochastically perturb biting rates with general state functional intensities. So, we derive a stochastic differential equation (SDE) which describes a vector disease with two types of hosts-humans and animals-and give con...

Chagas disease is an important neglected tropical disease which causes on average about 7,000 deaths per year, and an estimated 25 million people risk of acquiring it. This illness is often found in rural areas, which are usually characterized by poverty and presence of animals which act as reservoirs of the disease. Our main objective is to study...

We present a stochastic epidemic model with vectorial transmission and multi-host structure. To include environmental noise, we stochastically perturb biting rates with general state functional intensities. So, we derive a stochastic differential equation (SDE) which describes a vector disease with two types of hosts – humans and animals – and give...

en In some ecosystems, the invasion of species may lead to extinction or displacement of the local species that are in the medium. In this work, we present a theoretical predator–prey model based on reaction diffusion equations, where each species has a strong Allee effect. We use the diffusion coefficients as parameters in a one‐dimensional enviro...