In a typical puppy vaccination schedule, vaccines are given every how many weeks until what age?

• A. Every 4 weeks until 20 weeks
• B. Every 3 weeks until 16 weeks
• C. Every 2 weeks until 18 weeks
• D. Every week until 15 weeks

Answer: (B)

Puppies start with maternal antibodies that can block vaccines, and those antibodies wane unpredictably over several weeks. To reliably stimulate the puppy’s own immune system, vaccines are given in a series with short, consistent gaps so each dose can provoke a response before protection fades. A three-week interval balances giving enough time for the immune system to respond after each shot while progressing through the series quickly, so by about sixteen weeks most puppies have developed protective immunity. Ending the series around sixteen weeks ensures coverage before maternal antibodies are too low or exposure risk rises, after which boosters follow a regular maintenance schedule. Other intervals either stretch the window too long or compress it too tightly, which can leave gaps in protection.