Negative vaccine efficiency for Omicron Variant

According to official sources

My apologies — this data isn’t quite what it appears and so I’ve updated this document at strategic locations. The graphs show negative efficiency for two doses against the Omicron variant. The booster does return protection into positive territory, but I note that we expect boosters to provide some improvement in protection — the question is, for how long.

Yesterday the UK Health Security Agency released their latest Technical Bulletin on covid variants. Hidden deep in the bowels of this document was this rather important figure:

The graph on the left suggests that two doses of Astra Zeneca vaccine results in an increased risk of catching Omicron variant and having symptoms, compared with never being vaccinated in the first place. I note that the efficiency appears to increase in later weeks — I think that this might be an artefact, but I’d note that our period of concern is probably between now and February — and most of those only double vaccinated, including our healthcare workers and vulnerable, will be in this zone of negative efficiency during this peak risk period.

The booster does seem to return protection into positive territory, but we don’t have any information as to how long this protection will last and if it will manage to stay offering positive levels of protection this time (I doubt it).

That this analysis has used the troublesome Test-Negative Case-Control methodology, and I have my doubts that the 3x Pfizer vaccinated even have a vaccine effectiveness of about 40%, as indicated in the graph on the right (it is even possible that 2x Pfizer also has a negative vaccine efficiency against symptomatic infection — if only they’d make the effort to undertake a proper cohort study — it is rather important to get this right).

The bulletin makes a big point about high efficiency in the period from 2 week of the vaccination, however, there’s a big difference between short term protection (from 2 weeks to about 8 weeks) and longer term protection. This is because the vaccines do induce a short term IgA antibody response which does have an impact on protection against upper respiratory tract infections (unlike their trumpeted IgG antibody response, which doesn’t); however these vaccine induced antibodies wane to an insignificant level after approximately 7-9 weeks and it is the impact of the immune response to the vaccination after this point that really defines their protective function.

Two more points:

• This is for protection against symptomatic infection — how many more infections are asymptomatic?

• These people believe that they are protected, and vaccine passports means that they can enter crowded buildings without needing a negative test — is this negative vaccine efficiency going to result in far far more cases than if we didn’t have vaccine passports?

You’d think that this new data might explain why the authorities were so eager to get everyone boosted so quickly…