We arent too many months away from a whole year of these sorts of stories not getting the attention they deserve: https://www.bbc.co.uk/news/health-61093736
www.urban75.net
I already responded to that older post of yours at the time, explaining that what you had heard in the news in regards stuff from the ONS was nothing to do with antibodies, it was estimates based on the household PCR sampling done for the ONS infection survey, added up to cover the entire period of the pandemic that their infection survey had been active for.
The ONS do an antibody thing too, which gives figures far above the 70% you had heard about, their figures come out only a little below 100%. However their figures as routinely presented dont differentiate between infection and vaccination based antibodies. For example a few days ago they offered this:
But yes, I also explained that there are antibody tests which can differentiate between antibodies from vaccination and those from infection.vaccination. Specifically, Roche N picks up antibodies from infection only, and Roche S picks up antibodies from infection/vaccination. These can be found in the weekly vaccine surveillance report. See the details on pages 41 to 43 of this document for example:
eg:
Limitations of that data include that its from blood donors so not a perfect reflection of the entire population, that it is a little out of date, and that antibody levels are expected to fall over time, and are expected to be different in people that have already been vaccinated before getting infected. So this data is unlikely to properly capture all infection-related antibodies since the very start of the pandemic. eg that document says stuff like this:
Seropositivity estimates for S antibody in blood donors are likely to be higher than would be expected in the general population and this probably reflects the fact that donors are more likely to be vaccinated. Seropositivity estimates for N antibody will underestimate the proportion of the population previously infected due to (i) waning of the N antibody response over time and (ii) observations from UKHSA surveillance data that N antibody levels are lower in individuals who acquire infection following 2 doses of vaccination. These lower N antibody responses in individuals with breakthrough infections (post-vaccination) compared to primary infection likely reflect the shorter and milder infections in these patients. Patients with breakthrough infections do have significant increases in S antibody levels consistent with boosting of their antibody levels.
That sort of things explains why there is quite a difference between the infection-induced antibodies shown in this data, and the estimates for how many poeple have had Covid during the pandemic so far which are obtained via a different, non-antibody method entirely. And its the non-antibody stuff that people are most likely to have seen in the news in recent weeks. A lot of those news items were based on the following article from April 22nd:
Coronavirus (COVID-19) Infection Survey technical article: Cumulative incidence of the number of people who have tested positive for COVID-19, UK - Office for National Statistics
