Final answer:
False, The claim that vaccines cause dangerous viral infections is false, as they are designed to safely stimulate the immune system without causing the disease.
Step-by-step explanation:
The statement that vaccines can be harmful because they cause dangerous viral infections is false. Vaccines work by exposing the immune system to antigens or parts of pathogens that stimulate an immune response, without causing the disease itself. Different classes of vaccines, including those made from live attenuated viruses, killed viruses, or molecular subunits, are designed to prevent disease safely. It's important to note that all vaccines are rigorously tested for safety and efficacy, and severe adverse reactions are extremely rare. A successful vaccination campaign leads to immunity in the population against diseases that could otherwise cause serious health issues or even death.