Subjects Who Developed SARS-CoV-2 Specific IgM after Vaccination Show a Longer Humoral Immunity and a Lower Frequency of Infection

To assess whether IgM development was also associated with longer-lasting immunity, scientists analyzed anti-SARS-CoV-2 spike protein IgG and IgM, and anti-nucleocapsid IgG in 1872 vaccine recipients at different time points.