| Neither one really addressed the question of mandatory vaccination and its effect on mortality and herd immunity. |
| This was possibly due to temporal variation in other factors, such as viral incursions from surrounding countries and levels of herd immunity. |
| This pattern of rising and falling herd immunity explains why epidemic diseases tend to occur in waves i.e., exhibit a periodicity in prevalence. |
| Because of the herd immunity that exists because of mass vaccination, the unvaccinated are also protected. |
| There, public health officials have now documented mass HPV vaccination and the first glimmers of herd immunity. |
| They found no evidence that vaccination prevents viral transmission, putting the whole herd immunity myth once again into question. |
