However, this may not be a good idea for outsiders lacking immunity to local bacteria, but certainly it should be ok for brushing teeth.
That means Haitians lack immunity to the bacterium that causes the disease, and medical workers lack the experience to deal with it.
Isolated tribes may lack immunity to common diseases, which can kill a large percentage of their people after contact.
Some lacked immunity to this disease of evil because of some tragedy in their lives.
The American natives lacked immunity and resistance to these infections.
Lacking immunity to flu viruses, children are most likely to acquire the virus, spread it among themselves and transmit it to others.
Spread to the natives by contact with whites, the native population lacked immunity to the disease and it spread quickly.
Lacking immunity to the newcomers' diseases, the population was decimated by the mid-nineteenth century.
But their greatest ally was infectious disease, to which the natives lacked immunity.
Young equines may lack immunity because they have not had prior exposure.