"Better immunity" refers to a stronger defense system in our body that helps fight off harmful viruses, bacteria, and diseases. It means having a higher ability to stay healthy and not easily get sick. Full definition
Not only are vaccines licensed for use in healthy, clinically normal animals only, an animal who is sick will probably not be able to form good immunity in response to the vaccination. (caberfeidh.com)
Two - thirds of your immune system is in the cells lining the intestinal tract — good immunity starts with a good diet! (integrativehealthcare.com)
It has been quite difficult to produce vaccines to protect animals and people against pathogens that do not cause good immunity after recovery from a natural infection. (2ndchance.info)