Developing immunity

During the body’s first encounter with a pathogen, there will only be a very small number of lymphocytes with the specific receptors for the antigen. It then takes time for the cells to divide to form clones; B-cells to secrete antibodies, T-cells to destroy infected cells If the same pathogen invades again, memory cells give a faster, more effective response (antibody production is much faster)

An infection is an example of acquiring natural immunity. It is called active as your body needs to work to produce the necessary antibodies A mother breast feeding her baby is an example of passive immunity. Antibodies are passed to the baby in the milk, so the immune system doesn’t have to produce them. The milk (colostrum) that is produced for the first few days after birth is particularly rich in antibodies.

Vaccinations Active immunity: Antigen is injected into the body. This may be in the form of an inactivated bacterial toxin or attenuated (not harmful) virus. Passive immunity: injection of antibodies or antitoxins

Passive immunity doesn’t last as long as active immunity (only weeks or months): Lymphocytes are not stimulated to clone themselves Memory cells are not made This type of immunity can only last as long as the antibodies/toxins last in the blood

Live attenuated vaccines Dead/inactivated vaccines Subunit vaccines mRNA vaccines lively dinos savour munch

Approximately 80-85% of the population need to be vaccinated to stop the spread of the disease. This provides protection from the disease for individuals that can’t be vaccinated for a particular reason

There is a continual need for new drugs and antibiotics Thousands of prescription drugs are derived from plant species, many of which are found in tropical rain forests. For this reason among others, it is important to preserve the rain forest’s biodiversity.