Oral polio vaccine is highly effective and inexpensive (about US$0.10 per dose, or US$0.30 per child and its availability has bolstered efforts to eradicate polio. A study carried out in an isolated Eskimo village showed that antibodies produced from subclinical wild virus infection persisted for at least 40 years. Because the immune response to oral polio vaccine is very similar to natural polio infection, it is expected that oral polio vaccination provides similar lifelong immunity to the virus.
Contact immunity to polio can occur when attenuated poliovirus derived from the oral polio vaccine is excreted, and infects and indirectly vaccinates unvaccinated individuals.
Because mostly some microorganism may be very small and harmful that can affect humans or animals just by the experience of the microorganism.
Answer and explanation;
-A diverse community would be more resistant to disease, predation, and invasion because it would be a bigger diversity of genes, which means that the chance of disease would be more likely to spread in a different area than in a diverse population.
-Diversity is expected to increase the resilience of ecosystems. A diverse community would be more resistant to disease because of simple biology. The more sources for possible resistance the better the heterogeneous pool will be at resisting disease.
-High diversity strengthens a community and prevents invasion of the introduced predator. After a gradual loss of native species, the introduced predator can escape control and the system collapses into a contrasting, invaded, low-diversity state.
