highly significantp < 0.0001
In the other age groups, we observed a more moderate but still highly significant rise ( p < 0.0001) in antibody levels (2.9, 2.9, 1.8, and 1.66, in the age group 0–15 years, 31–45 years, 46–60 years, and >60 years, respectively) ( Table 2 ).