variant - n. something that is different in some way from others of the same kind

income –n. money that is earned from work, investments and business; used to describe the average amount of money people make is a certain place

booster (shot) –n. an extra amount of a vaccine that is injected into a person or animal that improves or extends protection against a targeted disease

expose - v. to cause something to be affected by a virus or something that could be harmful

emphasize - v. to give special attention to something

critical - adj. extremely important

peak - adj. filled with the most activity