Interestingly, despite that the MSP reported high infection rates in January and February 2022 due to the emergence of the Omicron variant, no association was found between IgM seropositivity and SARS-CoV-2 active infections in these periods (Mathieu et al., 2020b; Ministerio de Salud Pública, 2020). This evidence concerns the gene CD40LG and infection.