And Yet There's Oregon 3
OK — so I REALLY didn’t intend a part 3, but there have been a couple updates already.
This dropped on medrxiv last night: Effectiveness of COVID-19 Vaccines Against SARS-CoV-2 Infection During a Delta Variant Epidemic Surge in Multnomah County, Oregon, July 2021
Which measured the vaccine effectiveness in Portland, Oregon (emphasis mine): “Results: 500 case-control pairs were matched (n=1000). Overall effectiveness of any completed COVID-19 immunization was 73% (95% Confidence Interval [CI] 49-86%) and 74% (95% CI 65-85%) for mRNA immunizations and 72% (95% CI 47-85%) for individuals that had started but not completed mRNA immunizations. Conclusions: Our findings estimate high, yet reduced, VE during Delta variant dissemination. These results highlight the importance of COVID-19 immunizations for reducing SARS-CoV-2 infection while juxtaposing the need for additional non-pharmaceutical interventions. Importantly, the reduced VE identified here may predict future reductions in vaccine performance in the context of ongoing viral genetic drift.From my post yesterday: “If the Oregon case/death rate were in the 0.5% range, there should have been something like 4500 breakthrough cases there during this period. This would change Oregon's EV from 90% to be about 74%.”
I think this says the 70-ish% number is looking like the right one for Delta, that death rates between unvaccinated and vaccinated people are essentially the same (ultimately using that assumption is how I estimated the 74% number).The thing I was expecting to beg an update with sometime this weekend, was the next breakthrough case report from the State of Oregon.1
The column on the right is the new set of numbers, more cases and unfortunately deaths being reported. Quickly taking the new numbers and turning the crank on what we did in previous posts:
So for the previous week’s numbers we got:
With this week’s data we end up with:
Slightly lower, but given what we’ve seen and said above, the State of Oregon still seems to be under-reporting vaccinated cases (most states are. Oregon at least is providing a regular breakthrough report. Even data like this is hard to come by). It will be interesting to see how this progresses. Hope Oregonians take this mask business seriously and turn the case numbers the other direction though…
I mean I can’t get through one of these without a footnote — also in here am pulling daily data from the (pretty nice!) Oregon dashboards: https://public.tableau.com/app/profile/oregon.health.authority.covid.19/viz/OregonsCOVID-19DataDashboards-TableofContents/TableofContentsStatewide
since the weekly reports and the breakthrough reports do not line up on the same day. I suppose providing a fully consistent and complete dataset takes all the fun out of it…