Human Viruses and Vaccine Mechanisms

Human viruses are adept at growing in human cells by using specific receptors. This strength is used to weaken them for live vaccines by growing them in chick embryo cells, where they adapt but become less effective in humans. This adaptation allows the immune system to respond without causing illness, providing immunity.

How do human viruses typically gain access to human cells?

• By using specific receptors that match cell surface molecules

• By directly injecting their genetic material

• By disguising themselves as nutrients

• By breaking down the cell membrane

What is the key to creating live vaccines from viruses?

• Weakening the virus by forcing it to grow in different cells

• Combining the virus with other pathogens

• Allowing the virus to mutate freely

• Increasing the virus's strength in human cells

Why do most virus particles struggle to grow in chick embryo cells?

• They lack the necessary nutrients

• They are outcompeted by other microorganisms

• They cannot access the chick cells

• They are destroyed by chick cell enzymes

What happens to a virus as it adapts to grow in chick cells?

• It becomes more effective at infecting human cells

• It loses its ability to reproduce

• It becomes less effective at growing in human cells

• It becomes resistant to all vaccines

How do weakened viruses in vaccines help the immune system?

• They give the immune system time to respond without causing disease

• They directly produce antibodies

• They multiply rapidly to overwhelm the immune system

• They cause a mild infection to build immunity

What is the main benefit of using live vaccines with weakened viruses?

• They are effective against all types of viruses

• They require no booster shots

• They eliminate the virus from the body

• They provide immunity without causing the disease

What is the role of the immune system when exposed to a weakened virus in a vaccine?

• To mutate the virus further

• To ignore the virus as it is harmless

• To gather information and mount an antibody response

• To destroy the virus immediately