Obtained by steam distillation of the lavender flowers, lavender essential oil is effective in repelling dust mites, fleas, mosquitoes, ticks, bedbugs and spiders. Lavender does not kill insects. The aromatic scent of lavender is offensive, causing insects to flee the area.
The body's defense system. Most viruses do not cause serious diseases and are killed by the body's immune systemâits network of natural defenses. In many cases, people never even know they have been infected. But unlike bacteria, which can be killed by antibiotics, most viruses are not affected by existing medicines. Fortunately, scientists have been able to make vaccines, which help the body develop natural defenses to prevent many viral infections.
There are 4 main types of vaccines: 1  live attenuated vaccines, which contain a living, but weakened, form of the germ (organism); 2  inactivated vaccines, which contain a killed form of the organism; 3  subunit vaccines, which contain just the part of the organism that stimulates an immune response (the antigen); and.n antigen specifically induces the production of antibodies which can bind to it and neutralise it. While most vaccines work by inducing B lymphocytes to produce antibodies (see below), activation of T-cells â another type of immune system cell that helps protect against disease â is also important for some vaccines.