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54: Coveille a structuring project for UTC-LMAC

It was in the context of the ongoing health crisis due to Covid-19 that the National Institute of Mathematical Sciences and their Interactions (INSMI), one of the ten CNRS institutes, decided to set up a platform to coordinate actions involving modelling Covid-19 phenomena.

54: Coveille a structuring project for UTC-LMAC

Leading the Coveille Project, a sign of confidence

Miraine Davila Felipe is a senior lecturer at UTC-LMAC Compiègne Applied Mathematics Laboratory (LMAC). She is a member of the S2 team dedicated, in particular, to stochastic models and tools. In other words: models where a degree of randomness is introduced. She is leading the Coveille Project, a modelling project based on COVID-19.

It was after a call for expressions of interest (CEI) that three pairs, presenting jointly skills in deterministic and stochastic approaches and tools, were formed within LMAC to work on Coveille.  "I'm the most recently arrived colleague at UTC in 2019. The fact that my colleagues chose me to lead this project touches me enormously, because they are showing, by this gesture, a great mark of confidence in me", assures Miraine Davila Felipe.

It was while she was teaching at the University of Havana, Cuba, that the idea of coming to France first occurred to her. What triggered this? "Well, I met French research scientists from the École polytechnique visiting my university and was won over by the quality of mathematical research in France. This motivated me to apply for a Master 1 in Applied Mathematics at the same school. I was selected and won a scholarship. I continued with a joint Master 2 at Ecole Polytechnique and Paris VI - Sorbonne University - in mathematics applied to biology. This enabled me, during an internship at Télécom Paris, to gain initial experience in epidemiology. In particular, I worked on methods for estimating rare events in the case of communicable diseases, which could possibly lead to crisis situations from a public health point of view," she explains.

Hence her interest in epidemiology. She then went on to complete her PhD within a multidisciplinary team of biologists, mathematicians, statisticians and probabilists, led by a professor from Paris VI at the Collège de France. The theme of this thesis? "I worked on phylodynamic models, a relatively recent field of research. The aim is to study the spread of diseases in the population using the genetic data of the pathogen - virus or bacterium. These are models used particularly for diseases such as flu’, HIV or Ebola, characterised by a high mutation rate of the pathogens involved. Finding different genetic sequences of a given pathogen in patients allows us to reconstruct the transmission tree. In a nutshell: to say who infected whom over time, provided we have enough data to reduce uncertainty," says Miraine Davila Felipe.

This is a new field of research that makes it possible, for example, to estimate the date of the beginning of the epidemic and which research scientists are trying to apply to Covid-19. In this, they are helped by the emergence of sampling techniques that are fairly quick and inexpensive compared to what existed previously. "Currently on Covid-19, there is a site on which nearly 10 000 patient genetic sequences are stored. It should be noted that each individual hosts a certain number of viruses, with, however, always one that is over-represented. In general, it is the one that is most likely to be transmitted. Hence the possibility, thanks to the signature left by the virus, of reconstructing, with the help of statistics, phylogenetic trees of transmission. Of course, there are still many uncertainties, but this nevertheless allows us to make estimates in relation to the evolution of epidemics. We can thus estimate the reproduction rate of the virus or R0," she points out.

This is a field of research that she explored further during her post-doc at the Institut Pasteur from 2017-18 and then as a temporary teaching and research associate at the University of Nanterre, which she has been pursuing since her arrival at the UTC. "I have developed this type of model from a mathematical point of view and have obtained fairly robust theoretical results from an epidemiological point of view. The idea is to couple two very different but highly correlated variables: the dynamics of the epidemic at the population level, through the curves of patients over time, and the genetic dynamics of the virus thanks to mathematical transmission trees. We thus have dual sourced information", concludes Miraine Davila Felipe.

Finally, this is a field of research that she intends to apply, with other colleagues, at Coveille, a transverse project based on the modelling of Covid-19.