Hence, the higher levels of IgG4 to CSP in the semi-immune group compared with PfSPZ-CVac participants could hamper an effective pre-erythrocytic response after CHMI with PfSPZ and partially explain the lower rates of sterile protective immunity in Gabonese volunteers compared with PfSPZ-CVac, as well as the lower vaccine efficacy of whole PfSPZ vaccines or CSP subunit vaccines in malaria-exposed individuals compared with naïve populations.14 The gene discussed is DNAJC5; the disease is malaria.