Does prior immunization with measles, mumps, and rubella vaccines contribute to the antibody response to COVID-19 antigens?

BACKGROUND: Incidence and severity of SARS-CoV2 infection are significantly lower in children and teenagers proposing that certain vaccines, routinely administered to neonates and children may provide cross-protection against this emerging infection. OBJECTIVE: To assess the cross-protection induced by prior measles, mumps and rubella (MMR) vaccinations against COVID-19. METHODS: The antibody responses to MMR and tetanus vaccines were determined in 53 patients affected with SARS-CoV2 infection and 52 age-matched healthy subjects. Serum levels of antibodies specific for NP and RBD of SARS-CoV2 were also determined in both groups of subjects with ELISA. RESULTS: Our results revealed significant differences in anti-NP (P<0.0001) and anti-RBD (P<0.0001) IgG levels between patients and healthy controls. While the levels of rubella- and mumps specific IgG were not different in the two groups of subjects, measles-specific IgG was significantly higher in patients (P<0.01). The serum titer of anti-tetanus antibody, however, was significantly lower in patients compared to healthy individuals (P<0.01). CONCLUSION: Our findings suggest that measles vaccination triggers those B cells cross-reactive with SARS-CoV2 antigens leading to the production of increased levels of measles-specific antibody.

Differential Antibody Response to SARS-CoV-2 Antigens in Recovered and Deceased Iranian COVID-19 Patients.

The coronavirus infectious disease 2019 (COVID-19), which is initiated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has imposed critical challenges to global health. Understanding the kinetic of SARS-CoV-2-specific IgM and IgG responses in different subsets of COVID-19 patients is crucial to get insight into the humoral immune response elicited against the virus. We investigated IgM and IgG responses against SARS-CoV-2 nucleocapsid (N) and receptor-binding domain (RBD) of spike protein in two groups of recovered and deceased COVID-19 patients. The levels of IgM and IgG specific to N and RBD proteins were detected by ELISA. N- and RBD-specific IgM was higher in deceased patients in comparison with recovered patients, while there was no significant difference in N- and RBD-specific IgG between the two groups. A significant correlation was observed between IgG and IgM titers against RBD and N, in both groups of patients. These results argue against impaired antibody response in deceased COVID-19 patients.