1.   In fact being a carrier helps to boost natural immunity.

2.   Some, especially adults, have a natural immunity.

3.   And poisoned bait, he says, can be ineffective because mice may develop a natural immunity to the poison.

4.   Because of genetic mutations, they are bald and have little natural immunity to disease.

5.   Carina Blackmore, a veterinarian with the state health department, said the vaccine will not harm a horse that already has natural immunity to the virus.

6.   Chimpanzees, shown to have been the source of the AIDS virus, are unsuitable for research on treatments because they apparently have a natural immunity to the disease.

7.   Experts think it shows that very low levels of HIV can act like a vaccine that stimulates effective natural immunity, perhaps indefinitely.

8.   Growing up in the shaky environs of San Francisco, choreographer Margaret Jenkins developed a kind of natural immunity to earthquakes.

9.   If he survives, he will be on his way to developing the natural immunity that protects most adult Africans from fatal bouts with malaria.