A team of researchers based in Casablanca conducted a four-year genomic surveillance study, offering new lighting on the evolution of SARS-COV-2, the virus behind COVVI-19, in Morocco. Published in August in the journal Nature, this study reveals that the epidemic in Morocco follows the global trends of variants, while emphasizing the role of the country as a regional transmission crossroads.
Between 2021 and 2024, scientists led to 235 samples of patients with COVID-19 across the kingdom. Their analysis made it possible to identify three distinct phases: the co-circulation of Alpha and Delta variants in 2021, the complete domination of omicron from 2022, and the emergence of the highly mutated omicron sub-chicron sub-chicron. 1.1 and JN.1.45 in 2023-2024. These strains presented up to 89 substitutions of amino acids and 17 deletions, classifying them among the most escaping lines of the immune system ever recorded.
The study also revealed key demographic results: almost 80 % of patients were symptomatic, the majority between 20 and 40 years old, and infections by Delta were generally more severe than those caused by Alpha or Omicron.
Phylogenetic analysis has integrated the Moroccan epidemic into a broader global context, highlighting many bidirectional viral exchanges, especially during the Omicron wave. This positions Morocco both as a receiver and exporter of variants, reflecting its geographic role as a crossroads between Africa and Europe.
The researchers concluded by stressing the crucial importance of continuous genomic surveillance to adapt vaccines, strengthen the response to epidemics and anticipate emerging threats. They also called for increased investment in sequencing capacity, reinforced regional collaboration, and the creation of data sharing networks across North Africa.