When vaccines are not properly stored, they lose their effectiveness. When they are stored outside of the recommended temperature range, their potency is affected. When a vaccine’s efficacy is lost, it’s gone for good, and the vaccine is practically spoiled and useless.
If the vaccine is ineffective, it can result in various problems, including the patient not being adequately protected from the disease for which the vaccine is being given.
Vaccines are temperature-sensitive, especially live vaccines like measles, which are adversely affected by high temperatures. If it gets too cold, diluent (the solvent used in some vaccines) can also freeze. Certain vaccinations, such as those for pneumococcal disease and tetanus, can be destroyed as a result.
As you would expect, destroyed vaccines cost money, and replacing vaccines is also costly. Vaccines must also be maintained at the proper temperature from when they are produced until they are administered to the patients.