Credit ACIP/CDC
#17,765
We've an early report on the apparent effectiveness of the new (XBB) COVID vaccine in preventing COVID hospitalizations (vs. unvaccinated) in Denmark from a preprint penned by their Statens Serum Institut (SSI).
Because of their relatively small population (5.8 million), a well-monitored universal healthcare system, and a high degree of testing, Denmark has a unique ability to track the effectiveness and impact of each vaccine release.
According to their latest study, the updated vaccine has reduced hospitalizations by about 75% (over unvaccinated individuals). Unknown, of course, are how long this protection will last and how this vaccine will fare against future variants.
But for now, this is encouraging news.
The translated statement, and a link to the preprint, follow:
Autumn's covid-19 vaccines reduce the risk of hospitalization by 75 percent
The variant-updated covid-19 vaccines, which target newer variants of the coronavirus and have been given since October this year, provide good protection against serious illness.Last edited on November 16, 2023
The season's covid-19 vaccines, which have been offered to all Danes over 65 and selected risk groups since October, are effective and provide good protection against serious illness.
This is the conclusion of a study from the Statens Serum Institut (SSI).
The study shows that the vaccinated have approximately a 75 percent lower risk of hospitalization due to covid-19 than non-vaccinated from seven days after vaccination.
"We can see that the season's vaccine has a really good effect."Christian Holm Hansen, statistician and epidemiologist at SSI and is behind the studyTargets XBB 1.5.
From 1 October this year, all Danes over the age of 65, as well as people in selected risk groups, have been offered vaccination against COVID-19. It takes place this year with updated vaccines which are directed against the so-called XBB.1.5 variant, an omicron sub-variant which has dominated over the last year in Denmark as well as many other places in the world.
Although studies have been done showing that the vaccines are safe and effective in producing a robust immune response, there is not yet good real-world data on the protective effect of the vaccines in the population.
Good Danish registers
In Denmark there are good registers which are updated every day with very little delay.
"This means that we can always see who lives here and who has been vaccinated and when. We can also quickly get an overview of who has been hospitalized and with what. It is quite special that you have such good data on the population of an entire country - it is not something you have very many other places in the world. Thus, we are also in a position to investigate the protective effect of the vaccines quickly after the start of the vaccine rollout.”Christian Holm Hansen, statistician and epidemiologist at SSI
In the new study, data has been analyzed from the month of October this year as people were vaccinated. After that, the incidence of hospitalization due to covid-19 from 8-26 October among people who had received the new vaccine, compared to the incidence among people who had not yet received it. The study only included people who had also been vaccinated against covid-19 last autumn/winter.
Significantly fewer admissions
The results of the study showed that the incidence of hospitalization due to covid-19 was significantly lower among the vaccinated compared to the unvaccinated. The analysis, which i.a. is adjusted for sex, age and for underlying diseases shows that the incidence of new admissions is approx. 75% lower than among people who have not yet received the new vaccine.
"It is a reassuring result, which indicates that the new vaccine works effectively against the SARS-CoV-2 variants that abound at the moment."Christian Holm Hansen
The study has been published and is available in preprint here https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4627268 , and is awaiting peer review.
Effectiveness of the XBB.1.5 updated COVID-19 vaccine against hospitalisation: a nation-wide cohort study in Denmark, October 2023
3 Pages Posted:
Christian Holm Hansen, Ida Rask Moustsen-Helms, Morten Rasmussen, Bolette Søborg, Palle Valentiner-Branth, Henrik Ullum
Statens Serum Institut
Date Written: November 8, 2023
Abstract
The XBB.1.5 updated COVID-19 mRNA vaccines currently form part of the national immunisation programmes in many countries including Denmark. Here we present a cohort analysis with national electronic health registry data estimating the protection offered by the updated vaccines against hospital admission in October 2023.After adjustment in a Cox proportional hazards regression model for sex, age, residency region and comorbidities, those who had received the seasonal COVID-19 vaccine were much less likely to have been hospitalised for COVID-19 compared with those who had not received the vaccine (HR=0.247, 95% CI 0.157, 0.389), although a negative control outcome analysis indicated that the unvaccinated group had somewhat poorer health in general. Overall, our early results indicate a high level of protection from the XBB.1.5 vaccines.
