Which statement about vaccine adverse effects is accurate?

• A. Anaphylaxis is a major adverse effect.
• B. Mild fatigue is the only adverse effect.
• C. Rash never occurs after vaccination.
• D. Vaccines have no adverse effects.

Answer: (A)

Vaccines can trigger a range of adverse effects, from mild local reactions to rare but serious, life-threatening events. Anaphylaxis is a recognized, potential adverse reaction that, although very uncommon, requires immediate treatment. Because of its severity, it is correctly described as a major adverse effect. The other statements oversimplify or misstate the reality: fatigue can accompany vaccination but is not the only adverse effect, rashes can occur after vaccination, and vaccines, like any medical intervention, can have adverse effects—none are completely without risk. In practice, vaccines are designed and monitored to keep risks very small, with systems in place to recognize and treat any severe reactions quickly.