Both vaccines should work the same - essentially the first vaccine dose in someone who has previously had covid would act similar to the second dose of vaccine for someone not previously infected. Both vaccines just make the immune system respond to the spike protein, they just differ in how they get the person to make the spike protein to respond to - via viral vector being transcribed into mRNA and then assembled into protein based on the mRNA (oxford) or skipping the transcribing part for mRNA vaccines and going straight to making the protein based off the mRNA template.
Both the person with previous covid and the person after their first vaccine dose have had their immune system primed to see the virus - for the spike protein (mainly) and other proteins for the previously infected person and the spike protein only for the vaccinated person. The next encounter (first vaccine for previously infected/second dose of vaccine for other) then induces the immune system to respond rapidly a second time to virus spike protein and strengthens the immune memory. This immune repose will be fast and very strong - expect that second dose of vaccine to knock you out more than the first, essentially the body is mounting a huge response to a pathogen it has a memory of. There’s no slow ramp up of immune response this time - it’s exceptionally fast if the first encounter with the virus/spike has done what it should.
Appreciate the clarification dj, particularly the first paragraph.
Some ideas I was wondering about:
- Differences in the ability of an immune system primed with 'natural' Covid immunity to fight off a variant due to the difference in characteristics of a natural immune response to that prompted from vaccination, even a secondary vaccination.
- Whether in theory this would make the 'strongest' persistent immunity a moderate Covid infection followed by a vaccination (or the other way around) due to strong B, T and antigen capability.
- Whether the auto-adjuvanticity of the mRNA vaccines change the enduring T-response (in effect a different character of the short term immunity - as shown in the NHS study on reinfection released last week) and whether this response is more durable once we have higher levels of vaccination in the population.
- How does the above impact the antigenic drift we're seeing in emerging variants
I believe the last point is being tested as the durable antibody response is still being figured out 8+ months down from the trial groups, at least from what I read in a published article last week (NEJM maybe but don't hold me to that!).