Which statement about influenza vaccines is true?

Which statement about influenza vaccines is true?

• A. They provide 100% protection
• B. They never reduce the risk of infection
• C. They greatly lower the chance of catching the flu and help prevent spread
• D. They cause influenza

Answer: (C)

Vaccines against influenza work by teaching the immune system to recognize the virus, so they don’t provide perfect protection but do reduce the likelihood of getting sick. Seasonal flu vaccines are updated each year to match circulating strains, and their effectiveness varies by season and person. Even when a vaccinated person does get influenza (a breakthrough infection), the illness is often milder and less likely to lead to serious complications, and fewer people in the community become infected overall, which helps prevent spread. This is why the statement that influenza vaccines greatly lower the chance of catching flu and help prevent spread is true. The other ideas aren’t accurate: no vaccine is 100% protective, so 100% protection isn’t achievable; vaccines can reduce risk, so saying they never reduce risk is false; and vaccines do not cause influenza—their purpose is to stimulate immunity, with real influenza caused by the virus itself, not the vaccine.

Vaccines against influenza work by teaching the immune system to recognize the virus, so they don’t provide perfect protection but do reduce the likelihood of getting sick. Seasonal flu vaccines are updated each year to match circulating strains, and their effectiveness varies by season and person. Even when a vaccinated person does get influenza (a breakthrough infection), the illness is often milder and less likely to lead to serious complications, and fewer people in the community become infected overall, which helps prevent spread. This is why the statement that influenza vaccines greatly lower the chance of catching flu and help prevent spread is true.

The other ideas aren’t accurate: no vaccine is 100% protective, so 100% protection isn’t achievable; vaccines can reduce risk, so saying they never reduce risk is false; and vaccines do not cause influenza—their purpose is to stimulate immunity, with real influenza caused by the virus itself, not the vaccine.