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> For vaccines available in the UK, effectiveness against symptomatic Omicron infection ranged from 0% to 20% after two doses, and from 55% to 80% following a b

> For vaccines available in the UK, effectiveness against symptomatic Omicron infection ranged from 0% to 20% after two doses, and from 55% to 80% following a booster dose how does this make any sense? a booster is the same as the original vaccine, the only reason i can see this making any sense is if the vaccine effectiveness was waning over time and everyone who they tested had been 6+ months since their 2 doses edit: it appears they measure antibody titers as a means of determining whether youll get symptoms or not. I find it strange that the goalpost is now avoiding "symptomatic infection" instead of "severe desease". Cold symptoms are symptoms but they arent anything to worry about typically?

tester89 5y ago
At least in this test https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-provide-update-omicron-variant https://www.pfizer.com/news/press-release/press-release-deta... they did account for that, which does suggest that 3 doses are in fact better than 2 without the waning effect. > The sera were collected from subjects 3 weeks after receiving the second dose or one month after receiving the third dose of the Pfizer-BioNTech COVID-19 vaccine.
jlokier 5y ago
The doses do not all set your immune system to the same state, despite being the same substance. The subsequent doses cause further evolution within the body to broaden the spectrum of its response. This is why there were two doses in the first place, on a schedule, instead of one dose. The sequence is more like a progressive immune system training program than a one-off health powerup like you'd get in a video game. Omicron is close enough that the figures show a significant effect after the third dose compared with the second. It was not something which could be assumed, because the response curve depends on details of the virus, so the recent data is good news. However the scientists had enough understanding of the details, and Omicron spreads so fast with unknown consequences at this time, that it was worth rolling out the booster soon after Omicron was detected. It is a popular misconception that each vaccine sets a simple "immunity %" stat, and that the booster simply resets that stat after it wanes. It's an easy idea to explain, but the immune processes are more subtle than that. Perhaps we need some of that subtlety to be better known now, so that people understand why the booster sequence is useful. https://www.bbc.co.uk/news/health-59639973.amp https://www.bbc.co.uk/news/health-59639973.amp

tester89 5y ago

At least in this test https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-provide-update-omicron-variant https://www.pfizer.com/news/press-release/press-release-deta... they did account for that, which does suggest that 3 doses are in fact better than 2 without the waning effect. > The sera were collected from subjects 3 weeks after receiving the second dose or one month after receiving the third dose of the Pfizer-BioNTech COVID-19 vaccine.

jlokier 5y ago

The doses do not all set your immune system to the same state, despite being the same substance. The subsequent doses cause further evolution within the body to broaden the spectrum of its response. This is why there were two doses in the first place, on a schedule, instead of one dose. The sequence is more like a progressive immune system training program than a one-off health powerup like you'd get in a video game. Omicron is close enough that the figures show a significant effect after the third dose compared with the second. It was not something which could be assumed, because the response curve depends on details of the virus, so the recent data is good news. However the scientists had enough understanding of the details, and Omicron spreads so fast with unknown consequences at this time, that it was worth rolling out the booster soon after Omicron was detected. It is a popular misconception that each vaccine sets a simple "immunity %" stat, and that the booster simply resets that stat after it wanes. It's an easy idea to explain, but the immune processes are more subtle than that. Perhaps we need some of that subtlety to be better known now, so that people understand why the booster sequence is useful. https://www.bbc.co.uk/news/health-59639973.amp https://www.bbc.co.uk/news/health-59639973.amp