A vaccine is used to produce artificial active immunity. Once a person has been given a vaccine, there is a time interval before they acquire long-term immunity to the disease. Which statement about this time interval explains the delay in gaining long-term immunity?
- ANo memory cells have been produced from B-lymphocytes.
- BNo plasma cells have been produced from B-lymphocytes.
- CThe primary immune response has not produced enough antibodies.
- DThe secondary immune response has not produced enough antibodies.