Herd immunity indicate that large proportion of people in a certain community are immune. The implication is when there are few susceptibles the natural infection cannot keep going in the community and incidence goes down to a low leve
Kusatetezedwa kwa ng'ombe kumasonyeza kuti anthu ambiri m'dera linalake satetezedwa. Tanthauzo lake ndi pamene pali zochepa zomwe zingayambitse matenda achilengedwe sangathe kupitirizabe m'deralo ndipo zochitika zimatsikira pansi 