The results do not provide enough evidence to support alternative hypothesis because in other alternative calculation remains the same and it gives the same z with p value. The sample was appropriate for this study. The thumb rile says n>100 and we have samples size of n>500. Therefore since the size is more than the thumb rule then the sample was appropriate for the study. There are possible limitations to this study. These limitations are that after calculation we cannot define which vaccine is better. Assuming by thumb rule that data follow normal distribution, theres no evidence that it actually follows approximated normal distribution. In order to conduct a follow up study to this one is by comparing paired test. This would be reliable because these are independent samples. Practical significance is whether the differences are large enough to be out of value in practical sense. Statistical significance is the unlikelihoods that mean is different observed in the sample have occurred due to sample error (2012).
(2012).StatisticalVersusPracticalSignificance.UniversityofGuelphNumeracyProject.Retrieved from https://atrium.lib.uoguelph.ca/xmlui/bitstream/handle/10214/1869/A_Statistical_versus_Practical_Significance.pdf?sequence=7