WHAT IS AN ADDITIONAL DOSE OF A COVID-19 VACCINE :

• An additional dose, originally called a third dose
• Given to people with moderately or severely compromised immune systems
• To improve their response to the initial vaccine series
• Was used to refer to additional doses for the two mRNA vaccines, but now the term is “additional dose” because those who received a Johnson & Johnson “one dose” vaccine may also be eligible for a dose based on their immune systems.

WHAT IS A BOOSTER SHOT:

• Means of strengthening one’s immune system against a particular pathogen
• May be exactly the same original vaccine, in which case its goal is to increase the magnitude of protection by producing more antibodies.
• Additional dose after the protection provided by the original shot(s) has started to decrease over time
• One would get a booster after the immunity from the initial dose(s) naturally starts to wane.
• Designed to help people maintain their level of immunity for longer
• What a booster shot does is that it gives the memory cells the crucial signal to re-engage when the virus attacks.

DIFFERENCE BETWEEN THE TWO:

• A Covid-19 booster is given when a person has completed their vaccine series, and protection against the virus has decreased over time. Depending on the original series you had, some details will vary.
• An additional dose, however, is administered to people with moderately to severely compromised immune systems. This additional dose is intended to improve immunocompromised people’s response to their initial vaccine series