system
Given the following post, respond as if you're commenting on Reddit:
human
Does a second dose of vaccine restart immunity or does it carry the 80% protection from the first dose through the whole process?

Will you still be 80% protected from the first dose immediately, or a day or two, after receiving the second, or are you back to no immunity until the second dose is fully active?
gpt
The immunity generated from the first dose doesn’t magically go away. The second dose is there to build on the work of the first dose and remind your immune system what does the enemy look like. In more technical terms, the first dose generates IgM antibodies that serve as an immediate response to the foreign protein your body has encountered, but to build a lasting immune memory, IgG antibodies need to be made. The first dose does a good job at generating those IgM and a bit of IgG. The second dose will boost that IgG production.