The virus that changed my perspective and research

Dr. Erika Elizabeth Rodríguez Torres
Research Professor of Physics and Mathematics Academic Area

On March 20, 2020, a notification arrived that the Autonomous University of the State of Hidalgo (UAEH) was going to close its institutes for a month due to COVID-19. At that time, little did I know about this disease.

By April, a multidisciplinary team of researchers formed by physicist Ulises Paredes Hernández, mathematician Luis Alberto Quezada Téllez, food chemist Karla Montiel Solís, physician Isela Barrera, neuroscientist Enrique Vázquez Mendoza, architect Rogelio Molina Torres, as well as Mariana Aquino Morales and Citlalli Monzalvo, director of Web Technologies and Webometrics, opened a blog on the institutional website with the aim of keeping the university community and society in general up to date. You can consult it at the following link: https://www.uaeh.edu.mx/covid-hidalgo/

We included information from the World Health Organization (WHO), as well as telephone lines to provide psychological help and medical orientation that included home visits within the metropolitan area of Pachuca.

We added information on myths and realities of the pandemic, how to reuse masks, and how to use them. N95 because they became scarce for medical personnel. By May, the information was more varied because new symptoms of the disease were beginning to be discovered. As we walked through the pandemic, we realized that there was much to do and much to learn.

First research project is launched

As people dedicated to science, we began to ask ourselves questions such as, what is happening in the large cities where the highest rates of SARS-CoV-2 virus infections and deaths were reported?

So we decided to form a work team with Rogelio Molina Torres, Master of Architecture, Architect; Dr. Oralia Nolasco Jáuregui, from the Biostatistics Department of Tecana American University; Dr. Luis Alberto Quezada Tellez, mathematician from the Escuela Superior de Apán, and Dr. Benjamín Itzá Ortiz, from the academic area of Mathematics and Physics.

We began by analyzing the databases of the Health Sector and the National Institute of Statistics and Geography (INEGI) to calculate a comparative index of cases in 16 municipalities of Mexico City to identify three data: population density, per capita income and overcrowding; these components were multiplied by a common factor which was the number of cases registered by COVID-19.

At the time of the pandemic, the scientific literature assured that the poorest people and those with the greatest need to go out to work, without the possibility of sheltering at home, were at the greatest risk.

However, we found that, for example, in Milpa Alta, where per capita income is the lowest, there were few cases of infection because of its lower population density. The opposite in figures was Cuauhtémoc, which is the second most densely populated municipality in the CDMX. We also found that Iztapalapa, with higher data on overcrowding and a low per capita income, turned out to have a high rate of COVID-19 infections. The above is part of what we recorded in the scientific article that can be consulted at the following link: https://doi.org/10.1016/j.jum.2021.06.007.

New questions, second project

Our next concern was to find out what was happening with people infected by the SARS-CoV-2 virus in Mexico. So we reanalyzed official databases and followed each one for 79 days.

We knew that people with non-communicable diseases such as diabetes and hypertension were more vulnerable, but we wanted to identify age ranges and geographic location.

Among other results, we found that people with an average age of 40 years were mostly treated at home because they had less severe symptomatology. On the other hand, those over 55 years of age tended to be hospitalized for more severe symptoms. However, those with comorbidities such as obesity, diabetes and hypertension were more likely to present severe symptoms. We also showed that, of those hospitalized, there was a percentage, between 7 and 11%, who ended up intubated to receive oxygen.

Finally, we also observed that, contrary to what was being published that children under 5 years of age did not get COVID-19, we detected cases in this age range that presented symptoms equal to those of adults. All our findings can be consulted in the following publication: https://www.omicsonline.org/open-access/covid19-patients-analysis-using-super-heat-map-and-bayesian-network--to-identify-comorbidities-correlations-under-differ.pdf).

This work was possible thanks to the collaboration of Oralia Nolasco Jáuregui, researcher at the Biostatistics Department of Tecana American University, Dr. Luis Alberto Quezada Tellez, from the Escuela Superior de Apán, and Margarita Tetlalmatzi Montiel, from the academic area of Mathematics and Physics of the UAEH.

Finally, we work with vaccines

When the COVID-19 vaccines first came out, the team of scientists reasoned that richer countries would be more likely to vaccinate their populations. So what happens if everyone on the planet doesn't get it evenly?

In a nutshell, we started to analyze the asymmetric distribution of the vaccine that could promote what we call vaccine escape, i.e., coronavirus mutations that make it stronger and more resistant to the different immunizations developed so far.

Diseases such as polio or measles are well controlled by vaccination campaigns and rarely produce mutations. However, COVID-19 and influenza produce many mutants, which is why the latter must be vaccinated every year.

But the working group asked ourselves, what happens when we do not vaccinate evenly, not just one country, but the whole world?

To find answers, we proposed a mathematical model in which we took into account a small population that allows fewer replications and no mutation to occur. We observed that in densely populated cities such as Mexico City, non-immunized people spread the disease more effectively.

If the population is vaccinated symmetrically there is greater control of coronavirus mutations; but asymmetrically these mutants have a very selective advantage over the wild strain. Transmission and vaccine resistance becomes greater because of vaccine escape. The findings of this research can be consulted at the following link: https://www.medrxiv.org/content/10.1101/2021.03.27.21254453v2

The work was carried out in collaboration with Dr. Philip J. Gerrish, Department of Biology, University of New Mexico; Drs. Fernando Saldaña and Jorge X. Velasco Hernández, both from the Instituto de Matemáticas, Universidad Nacional Autónoma de México; Dr. Benjamin Galeota-Sprung from the Department of Biology, University of Pennsylvania; and Dr. Alexandre Colato from the Departamento Ciências da Natureza, Matemática e Educação, Universidade Federal de São Carlos, in Brazil.

In conclusion, I can tell you that, first of all, you have to be vaccinated. Secondly, the variety of mutants generated is stronger, so even if we are immunized, we can still become infected, although with the possibility of it being less serious. Thirdly, vaccinated or not, keep the basic measures which are the use of masks, keeping distance and constant hand washing.