Thursday, September 09, 2021

Denmark: More Research Finding A Greater Risk Of Hospitalization With The Delta Variant


 The Dominance Of Delta - Credit CDC NOWCAST

#16,173

The above graphic from this week's CDC NOWCAST shows that Delta variant comprises roughly 99% of all cases in the nation (based on extrapolation of recent sequence surveys), making Delta the most robust, and dominant, COVID variant seen to date. 

Whether Delta's dominance is permanent - or like Alpha before it, is only transitory, and will yield to another variant down the road - is unknown.  But for now, if you have COVID - and reside in the United States - you almost certainly have the Delta variant. 

Since its emergence last spring, we've seen a number of studies suggesting that Delta is not only far more transmissible than Alpha or the `wild type' before it, it also produces more severe illness. A number of countries have reported increased hospitalization with Delta, but fatality rates have not risen, possibly due to better treatments available now compared to 2020. 

The Lancet: Hospital Admission & Emergency Care Attendance Risk for SARS-CoV-2 Delta Variant Compared with Alpha

CDC Elevates Delta (B.1.617.2) Variant to VOC & Lancet Report On Hospitalizations & Vaccine Effectiveness

UK PHE Update, Technical Briefing & Revised Risk Assessment On COVID Variant B.1.617.2 (Delta) - June 3rd, 2021

Today Denmark's SSI has published a summary of research out of Denmark which also finds a doubled-risk of hospitalization with the Delta variant over Alpha. 

First the report from the Statens Serum Institut, then a link and an excerpt from the Lancet Correspondence.


The Delta variant carries a greater risk of hospitalization among the unvaccinated
There is a greater risk of being admitted to hospital if you have not been vaccinated against covid-19 and become infected with the Delta variant. This is shown by a new study from the Statens Serums Institut. The results have just been published as a commentary in the journal Lancet Infectious Diseases.

Last edited September 9, 2021

If you are not covid-19 vaccinated and become infected with the delta variant, there is a 201% greater risk that the infection will lead to you being admitted to hospital than for the alpha variant.

This is the conclusion from a new research study from the Statens Serum Institut (SSI), Aalborg University and the Danish Covid-19 Genom Consortium.

The analyzes have just been published in the journal Lancet Infectious Diseases as a commentary on a study from England that shows a risk of 132%. An increased risk has also been seen in a study from Scotland (82%) and in a study from Canada (108%), but not in Norway.

Harder to assess the severity of new variants

SSI estimates that the different risk variables may reflect that the severity of new variants becomes more and more difficult to assess.

"This is because we are now experiencing fewer tests, other infection patterns, and a change in behavior, all the while the vaccines are being rolled out," says SSI's technical director Tyra Grove Krause.
Vaccination is important

The more contagious delta variant was first detected in India in December 2020. It has since spread to most of Europe and also in Denmark, where it now accounts for close to 100% of all virus-sequenced cases of infection.

SSI has previously shown vaccination provides high protection against covid-19 hospitalization after infection with the Delta variant (94% for Pfizer and 97% for Moderna), and the new results again support the importance of being vaccinated and of course adhering to the general advice on infection prevention from the National Board of Health. ” says Tyra Grove Krause.
Read more

Read the new study here

A Brief excerpt from their correspondence follows. Significantly, this  200% increase in hospitalization risk was only observed in those who were not fully vaccinated.  Follow the link to read the letter in its entirety. 
Correspondence


Refers to

Katherine A Twohig, Tommy Nyberg, Asad Zaidi, Simon Thelwall, Mary A Sinnathamby, Shirin Aliabadi, Shaun R Seaman, Ross J Harris, Russell Hope, Jamie Lopez-Bernal, Eileen Gallagher, Andre Charlett, Daniela De Angelis, Anne M Presanis, Gavin Dabrera Hospital admission and emergency care attendance risk for SARS-CoV-2 delta (B.1.617.2) compared with alpha (B.1.1.7) variants of concern: a cohort study

The Lancet Infectious Diseases, Available online 27 August 2021, Pages Download PDF


(Excerpt)

To corroborate these results, we updated our Danish national analysis of hospitalisation risk associated with the alpha variant between Jan 1 and March 28, 2021,4 with cases until June 27, 2021, including patients with the delta lineage. We found a similarly increased risk of hospitalisation associated with the delta variant (risk ratio 2·83 [95% CI 2·02–3·98]; appendix p 2). Our analysis included 44 patients admitted to hospital with the delta variant, only four (9%) of whom were admitted more than 14 days after first vaccination. 

The risk of hospitalisation was only significantly increased among non-vaccinated people and among those who tested positive within 14 days after the first vaccine dose (appendix p 2). We consider the two study findings comparable (because the underlying populations had similar COVID-19 vaccine coverage and rollout for doses one and two, and despite the Oxford-AstraZeneca ChAdOx1 vaccine comprising approximately 3% of administered vaccine doses by June 23, 2021, in Denmark, which is lower than in England). In addition, there were only minor differences between the analyses in regression method and adjustment factors.



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