With the shift to AppleCare+, Genius Bar staff will no longer have the option of offering free replacements, so customers who have been aware of Apple's informal replacement policy should be mindful of the change.
Prevention of TB involves both early treatment to reduce transmission and isolation of the infected person until they are no longer contagious. There is a vaccine against TB, but it is not used routinely in the U.S. because of efficacy issues and other problems.
1 You need to take many medicines for TB for at least 6 months to rid your body of the TB bacteria. You should begin to feel better within a month of starting the medicines.  For the first 2 to 4 weeks after starting the medicines, you may need to stay home to avoid spreading TB to others.