Friday, April 23, 2021

Eurosurveillance: Characteristics of SARS-CoV-2 VOCs B.1.1.7, B.1.351 or P.1: Data from 7 EU/EEA Countries

 

#15,922

There is great controversy over just how dangerous the newly emerging VOCs (Variants of Concern) truly are, with some researchers openly questioning the original and updated NERVTAG Report On Increased Severity With COVID Variant B.1.1.7 that pegs the variant as being as much as 60% more lethal than the original COVID virus.

A Lancet study, published earlier this month - which looked at hospitalized patients - found no increased risk of death with B.1.1.7.

While these may appear to be mutually exclusive findings, there is another interpretation that works.  B.1.1.7 is believed roughly 60% more transmissible than `Classic COVID' - and may even cause more moderate-to-severe illness - resulting in a greater number of infected, and hospitalized patients. 

Once hospitalized, B.1.1.7 cases may be no more likely to succumb than non-VOC patients, but overall the variant could still be deadlier if your odds of being hospitalized with a VOC are substantially higher. 

And that appears to be the finding of this latest offering from Eurosurveillance, published yesterday, which finds:

A larger proportion of VOC cases were admitted to hospital (B.1.1.7/SGTF 11.0%; B.1.351 19.3%, and P.1 20.0%; p < 0.001 for all VOC) and ICU (B.1.1.7/SGTF 1.4%, p = 0.002; B.1.351 2.3%, p = 0.001 and P.1 2.1%, p = 0.005) compared with non-VOC cases (7.5%, hospitalised and 0.6% requiring ICU; Table 1, Supplement A, Figure S6).

While at the same time, they found:

In the age-stratified models, B.1.1.7/SGTF cases in the age groups 20–39 and 40–59 years had, respectively, 3.0 and 2.3 times higher odds of hospitalisation when compared with non-VOC cases, while ICU admission or death did not differ significantly in any age group (Table 3).

The full report is very much worth perusing.  I've only reproduced the Abstract and some excerpts from the discussion/conclusion, so follow the link to read it in its entirety.



Here, we analyse coronavirus disease (COVID-19) cases infected with any of the three severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOC): B.1.1.7/S gene target failure (SGTF), B.1.351 or P.1. We compare them with cases reported as infected with non-VOC virus with a focus on disease severity.

SARS-CoV-2 variant viruses 

In December 2020, the United Kingdom (UK) reported an emerging SARS-CoV-2 VOC classified as Pangolin lineage B.1.1.7 [1]. In the UK, and shortly thereafter in Denmark, B.1.1.7 infections increased rapidly. In parallel to the identification of B.1.1.7, increased whole-genome sequencing (WGS) efforts globally led to the identification of further SARS-CoV-2 VOC, including B.1.351 (described in South Africa) or P.1 (originating in Brazil) [2-6]. While viral evolution is expected and has occurred since the discovery of SARS-CoV-2, these VOC were associated with higher transmissibility and severity as well as altered antigenicity with potential implications for acquired immunity or effectiveness of current vaccines compared with other circulating lineages lacking particular defining mutations such as E484K, N501Y or del69-70 [7-12].

Discussion
 
This analysis outlines the characteristics of SARS-CoV-2 VOC infections in seven EU/EEA countries and suggests a higher risk for hospitalisation, and also for ICU admission in age groups < 60 years for B.1.1.7/SGTF, B.1.351 and P.1. Similarly, Germany reported increased hospitalisation in age groups < 60 years following B.1.1.7 dominance [16]. Earlier, higher infection rates in younger, school-age age groups with subsequent infections across all age groups have been observed in the UK [7,9]. Higher odds of hospitalisation for B.1.1.7 cases have also been reported by Denmark [8], but there is currently a lack of published data on severity for B.1.351 and P.1.

(SNIP)
 
Although testing for variant viruses in December 2020 mainly targeted travellers from affected countries and their contacts, only a minority of cases in our analysis for whom data was available for the study period were reported as importations. Testing of contacts of travellers or targeted testing in schools or workplaces generally or in response to outbreaks could also explain higher detection rates in younger age groups. Finally, the pooling of SGTF cases with B.1.1.7 cases could have led to some misclassification, despite evidence of high correlation between these cases. However, a small minority of 130 such cases had information on hospitalisation, which makes it unlikely that they had substantially impacted the severity outcomes.

Conclusion

We show an increased risk for hospitalisations and ICU admission associated with the SARS-CoV-2 variants B.1.1.7/SGTF, B.1.351 and P.1, also in middle-aged individuals, which underlines the necessity to rapidly reach high levels of vaccine coverage and adhere to public health measures to reduce SARS-CoV-2 incidence and prevent severe cases. Enhanced testing and contact tracing implemented with a special focus on cases with VOC are also measures to reduce spread.

          (Continue . . . )

It is probably also worth noting that hospital treatment for COVID has improved somewhat over the past 12 months - at least in areas which are not currently inundated with cases - and that may be skewing hospital fatality data in some cases. 

While this study won't settle the matter, and the debate over the impact of COVID variants will continue, this paper adds another checkmark to the more severe side of the ledger.

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