Objectives: Helminth
parasites infect over a quarter of the global population and can
profoundly modulate host immunity, potentially influencing vaccine
performance and the spread of pandemic pathogens such as severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite the high global
endemicity of helminth infections, their impact on immune responses to
various COVID-19 vaccines remains unknown. This study aimed to evaluate
the impact of Schistosoma infection on the immunogenicity and protective efficacy of messenger RNA (mRNA)- and protein-based COVID-19 vaccines.Methods: Mice with Schistosoma
infection and non-infected controls were immunized with either an
mRNA-based COVID-19 vaccine or an alum-adjuvanted spike protein vaccine.
Vaccine-induced humoral and cellular immune responses were assessed,
and protective efficacy was evaluated using a SARS-CoV-2 challenge
model.Results: COVID-19 mRNA vaccination induced strong spike-specific antibody and CD4 T-cell responses in Schistosoma-infected
mice comparable to non-infected controls, despite a
Th2/regulatory-biased immune environment, although multifunctional CD8
T-cell responses were reduced. Alum-adjuvanted protein vaccination
elicited robust humoral but weaker cellular immunity, with comparable
immune responses in infected and non-infected mice. Following SARS-CoV-2
challenge, both vaccine platforms conferred effective protection, with
substantial viral clearance and minimal lung pathology.Conclusions: mRNA
and protein vaccines elicit distinct immune profiles; however, both
protect effectively against SARS-CoV-2 infection in mice with concurrent
helminth infection.
FörderungenDZIF Academy European Union Helmholtz Association's Initiative and Networking Fund Deutsche Forschungsgemeinschaft (DFG) DZIF BMBF GoBio project Bavarian Ministry of Science and Arts State of Bavaria