Project led by Dr. Paulo Paixão studies the impact of COVID- 19 in children immune system

Project led by Dr. Paulo Paixão studies the impact of COVID- 19 in children immune system

A study is in progress to try to understand the impact of COVID-19 in humoral and cellular immune response in children during the infection and then three and six month after it. In addition, the second goal is to understand the different immune response between mild, moderate and severe infections. This study is led by Dr. Paulo Paixão (from Microbiology Laboratory of NOVA Medical School and CHRC researcher) through the project “Persistence of specific humoral and cellular immunity in children after SARSCoV - 2 infection”. 

Dr. Paulo Paixão explains the background and study design.

“The role of children in the COVID-19 pandemic has been widely discussed. Children have milder symptoms and are less likely to be hospitalized compared to adults. Moreover, this pandemic raised many other challenges and one of them is the persistence of immunity (after natural infection or immunization), in adults and in children. Thus, our aim was to monitor children infected with SARS-CoV-2 to assess immune responses during acute infection and after 3 and 6 months in patients experiencing different levels of disease severity, including the Multisystem Inflammatory Syndrome in Children (MIS-C). To achieve this, we are studying specific IgGs responses, assessed with classic immunoassays. Additionally, cellular immunity evaluation is being performed with immunophenotyping protocols and different functional assays against specific SARS-CoV-2 antigens in the Immunology laboratory of NMS. In brief, to assess the presence and extent of specific cellular responses, antigen specific CD25+ CD134/OX40+ CD4 T cells are evaluated by flow cytometry upon stimulation, as applied to other viral antigens in routine diagnostic settings. Also, immune profiles with cytokine production (IFN-gamma, IL-17, IL-21 and IL-10) are assessed upon specific and non-specific stimulation.”

Dr. Paulo also presented us the first preliminary data of this study.

“So far, we observed that in our cohort, MIS-C was more common in boys, as reported in literature. After an initial important increase in CD38+HLA DR+ activated T cells, these normalize at 3 and 6 months after infection. After acute disease, the percentages of memory B-cells and plasmablasts increased, and proliferative responses against the virus seem to increase as well from acute infection on. We are still waiting for the final analysis of all patients to complete these promising initial data.”

This project is led by Dr. Paulo Paixão and involves NOVA Medical School researchers from Microbiology Laboratory (Maria Jesus Chasqueira), Immunology Laboratory (Catarina Martins, Luís Miguel Borrego, Miguel Ângelo Dias) in partnership with Hospital de D. Estefânia/Centro Hospitalar Lisboa Central (Maria João Rocha Brito) and Clinical Pathology Laboratory of CHLC (Vitória Matos). 



Andreia Santos


Paulo Paixão