How Do Vaccines Work
Dr. Kristine Tsai
5/25/20252 min read


Inactivated (non-live) Vaccines work by taking a small blueprint protein of the enemy virus or pathogen (a small piece of the puzzle) and introduces this puzzle piece to our body (usually the muscle cells in your arm, thigh or bottom). This puzzle piece is foreign to the body, so it activates your cells to "present" it to your body's military/army (your immune system), who studies this puzzle piece and begins training exercises and creating weaponry (like neutralizing antibodies) to defend against this foreign invader. Because the puzzle piece blueprint is just a blueprint - it cannot infect or destroy cells - so it simply gets gobbled up by your immune system or degrades on its own in a few days.
While your immune system goes through its military training exercises, you will feel like you're getting a major internal workout, especially if it's a particularly effective vaccine. You get soreness or swelling in the arm and lymph nodes, some chills, fatigue, sometimes a fever (which is activated by your immune system) and body aches. Usually a very limited and short training exercise, most people feel better after about 3-4 days of this workout and your immune system is now newly trained, and therefore, stronger, to defend against the real, full strength, foreign invader.
Extra vaccine doses and boosters are simply allowing the immune system to re-train (continuing education, if you'd like to call it) to build more weaponry (antibodies) against the disease (as the weapons may need polishing or replenished from time-to-time).
Many Modern Vaccines are NON-LIVE, inactivated viruses. They cannot "infect" the immune compromised. This is why those who have weak immune systems or are pregnant can safely take these vaccines. There are a few LIVE-Weakened vaccines currently still given (such as the measles vaccine), therefore it is crucial that you speak with your trusted healthcare physician or licensed clinician to ensure you are safely getting a vaccine.
Vaccines are a major landmark of our health and wellness in modern society - it has given us an incredible tool to fight infectious disease and has increased life-expectancy and quality of life of humans over the past century.
Primary Care Expertise
Discovering & inspiring wellness and adventures in individuals and communities, delightfully!
BUSINESS CONTACT
BLOG INSIGHT & REVIEWS
info@delightfulmd.com
P: +1.614.468.3118
© 2025 The Delightful MD. All rights reserved.
Dr. Kristine Tsai practices in the Central Ohio Region. Her current in-office practice does not manage and is not an affiliate of or partnered with The Delightful MD. The information presented on this site is for general education, resources and opinion discussions and is not intended to replace the careful and personalized advice from your own physicians - please ensure continuity of your health care with your dedicated health team and contact them with any medical concerns. Site opinions and content cannot be considered legal advice. Scientific content is ever-changing, and educational pieces are only as current as the date posted on the site content or blog. Clinical questions or concerns will not be addressed by the staff of The Delightful MD.
F: +1.888.366.1236
(HIPAA Compliant Fax)

