Mixed effects model analysis showed that there were highly significant differences (p<0.001) between the 21–30 years group (youngest vaccinees) and the 31–40, 41–50, and 51–60 groups, as well as a marginally significant difference (p = 0.092) between the 21–30 and the 61–72 years group ( Table 7 ).
In both cases, a strong association was found between gender and regional pain by three exact tests of independence (Pearson’s chi-squared, likelihood-ratio, and Fisher’s exact test), indicating a significant trend for women to develop this reaction compared to men (p = 0.002 and p<0.001 for the first and second vaccine dose across tests, respectively).
The corresponding correlations of male and female age groups with titers for the second period was -0.36 and- 0.07975, respectively, and they were marginally statistically significant (p = 0.043) and not significant (0.48), correspondingly.