Really had a good chance to look through the UK data at length.
First, it's a lot better data set than I had thought. I didn't realize they were doing sequencing to parse out Delta.
While there is no denying the booster decreases infection risk vs 2 shots, that increase is quite small, 10-15% increase. That increase holds true as immunity wanes on a sliding scale through week 10 and does so with such a similar pattern that it's pretty safe to assume that continues on beyond week 10. After 5 months preventing contagion is approaching zero again.
It's really consistent across different vaccines, with or without past infection, etc. There are differences. People with past infection tend to do about as well as people with 2 shots. The people fully vaccinated with booster with a past infection do the best but it's not a huge difference.
For me, I basically had 0 protection agianst infection from Omicron despite being fully vaccinated and boosted since I am more than 5 months removed from booster. I kind of already knew this but shame on the Government for leaving that window open for the most susceptible groups of people. They should have been promoting a 4th or even 5th shot for some people by now if the goal is to prevent infection. My wife should have had a coin flip chance of not getting infected 6 weeks past her booster shot. My kids should have had a coin flip chance as well. Unfortunately all three lost their coin flip. Same goes for the rest of my family and most friends regardless of vaccine status, prior infection, etc. So far, in my large circle of friends and family if you get exposed at any decent level your are getting sick.
Also worth considering there is nothing in the way of causation for that data. Does the person who is getting double vaxxed and boosted take more precautions than the person that is unvaxxed? I think we all can agree that is probably the case with a relatively high degree of certainty but we don't know how much that accounts for the differences in the data. So in the real world, the vaccine is likely even less effective at preventing infection but it is impossible to say by how much. It's almost certainly what explains the difference in my group as well. We've quit trying to not get infected and it shows. I say quit, I still don't go into crowded places, still wear masks on airplanes and at airports. Rarely go out to eat. Haven't been to a sporting event, concert, convention, etc. I did have dinner with my family. I have eaten out 3 times in the last 3 months but only in relatively empty places. So even then, I can't say I haven't completely given in. I will now though.
So from the time of booster to having a less than 50% chance of preventing infection, the window is only about 10-11 weeks and that is under the assumption that people getting vaccinated and boosted are taking similar precautions to those that aren't getting vaccinated.
I really think this is strong evidence that suggests if we are going to do booster shots we need to greatly increase capacity to roll shots out and focus on booster drives at the appropriate time. While the waves aren't exact with seasonal change they have been consistently been within a few weeks. Then again, that window of preventing contagion is so small that it may just delay the inevitable and spread the wave out over a longer period. If our goal is to reduce infection then we need to come up with a booster schedule that includes boosters 5 times a year for everyone to reduce infections by 50% with the understanding that 50% probably also involves some mitigation efforts to reach that level of effectiveness.
Let me know when this starts to sound silly.
The good news, the data also shows that Omicron is indeed much less severe across the board on magnitudes of a sheet ton and vaccines tend to hold up for longer against severe disease than they do to prevent infection.