When we are exposed to antigens the body sends an immune response to prevent any infection or disease. Vaccines contain the same parts of antigens that can cause diseases, though they are weakened so that they don't actually cause disease, then they trigger the immune system to produce antibodies, which then help to fight against pathogens.
It introduces the body to a virus strand(s) to initiate internal resistance, which is created after a variety of metabolical processes. The idea is that the body would develop immunity to the virus without actually "getting" the virus.
After about 48 to 72 hours -- or once the swelling has satisfactorily decreased -- heat can then be used to increase blood flow to the injury and aid your recovery.
If it was 1250 J of work done, and a object that weights 50 N, you subtract 50 from 1250 which is 1200 J. Work has been done, so you subtract the high number from the lowest.
