COVID-19

1. The administration of a vaccine to help the immune system develop protection from a disease
4. A wave or series of waves of a certain disease
5. A small part of material selected for inspection or analysis
8. A change in a DNA sequence
9. The identification of the disease
11. A condition in which your airways narrow and swell
12. A medical scientist that studies viruses
14. An organism causing disease to its host
15. To be contaminated with disease

2. The continued presence of infectious virus following the primary infection
3. A virus that is no longer dangerous and cannot cause any harmful effect
6. A group of signs and symptoms that occur together and characterize a particular abnormality or condition
7. Different types of a virus
10. An organism’s complete set of genetic instructions
13. A new dose of vaccine that is received when previous is already inactive