But the drugs don't provide permanent immunity, so constant monitoring is necessary to make sure malaria doesn't return. (canadianbusiness.com)
The question of whether it is better for healthy children, who rarely suffer complications from flu, to get the flu and develop permanent immunity to that flu strain or it is better for children to get vaccinated every year to try to suppress all flu infection in early childhood is a question that has yet to be adequately answered by medical science. (wellnessmama.com)
Analysis, he had found, had little effect on the latter, whereas suggestion often «supplied immediate help and permanent immunity from the return of the habit.» (religion-online.org)