Covid, how hospitalizations change with the Delta variant
Hospitalizations and Sars-CoV-2: what emerges from the study published in the scientific journal Lancet
A study published in the scientific journal Lancet certifies what empirical experience had already hinted: the Delta variant of SARS-CoV-2 causes twice as many hospitalizations as the previous Alpha.
Alpha variant
As reported by the study 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 when the Alpha variant began to circulate it had a higher transmissibility than the previous wild strain. It quickly became the predominant strain accounting for 95% of cases in England in early February 2021. This variant was identified in 154 countries and was until recently the most widespread lineage in Europe and North America.
Delta variant
The delta variant was first reported in India in December 2020. After the previous waves of COVID-19, the number of confirmed and test positive cases in India increased rapidly, with around 30% infected in April 2021. he had contracted the delta variant. In England, instead, the delta variant was first detected in March 2021 . The percentage of cases in England caused by the delta variant has increased rapidly, reaching over 50% of the swabs sequenced by May 25, 2021.
WHO indications
WHO has outlined three criteria to designate the risk level of variants: increased transmissibility, increased virulence, change in the clinical presentation of the disease, and decreased effectiveness of health policies, social measures, available diagnostics, vaccines and therapies.
The delta variant: high transmissibility
Since March 2021, when the delta variant was registered in England, it has quickly become the predominant line, due to the high transmissibility. This variant has been shown to be associated with more severe disease than the previously dominant alpha variant (B.1.1.7).
The English study
The study was conducted among COVID-19 patients in England between March 29 and May 23, 2021 affected by the alpha or delta variant. 43,338 COVID-19 positive patients were analyzed , 8682 with the delta variant, 34 656 with the alpha variant, mean age 31 years. Data from these patients were compared with health data sets on vaccination, emergency care, hospitalization and mortality from the Public Health England Surveillance System, National Immunization Management, NHS Digital Secondary Uses Services, and Emergency Care Data. Set.
More aggressive delta variant
The results of the study speak of a greater aggressiveness of the delta variant . 2.3% of patients (196) with delta variant versus 2.2% of patients (764) with alpha variant were hospitalized 14 days after sample collection, in addition 5.7% of patients with variant delta (498) underwent emergency care against 4.2% of patients with the alpha variant, about 1448 people.
The most affected are the unvaccinated
In both groups, the majority of patients were unvaccinated, about 74% in both groups. The study showed a modest reduction in the efficacy of the vaccine against infection with the delta variant however vaccination has been shown to be able to reduce the risk of hospital admission. However, overall, the number of hospital admissions was low in the vaccinated subgroup.
The Scottish study
The Lancet analysis also reports a Scottish study published in PubMed that evaluates the data of 7723 patients with the delta variant and 11,820 with the alpha variant between 1 April and 6 June 2021. The results confirm the English study, tracing a risk higher hospital admission within 14 days for patients with the delta variant compared to the alpha variant (Added value of this study. The evidence from these two studies, Scottish and English, suggests that COVID-19 patients infected with the delta variant have approximately twice the risk of hospital admission compared to patients with the alpha variant.
Vaccinated and hospitalized
According to the study published by the Lancet “further research is needed to clarify whether the risks of hospitalization differ in vaccinated people infected with the delta variant compared to the alpha variant”. However, the Effectiveness of COVID-19 vaccines against hospital admission with the Delta (B.1.617.2) variant study estimated a low risk of hospitalization for individuals vaccinated after infection with one of the two variants. As reported by the BBC, according to this study, the efficacy of the double dose of Pfizer and AstraZeneca in avoiding hospitalization amounts to 96 and 92% respectively. "These two studies suggest that outbreaks of the delta variant in unvaccinated populations could lead to a higher health burden – the study reads -, particularly compared to previous prevalent strains of SARS-CoV-2."
This is a machine translation from Italian language of a post published on Start Magazine at the URL https://www.startmag.it/sanita/covid-come-cambiano-le-ospedalizzazioni-con-la-variante-delta/ on Tue, 31 Aug 2021 06:01:05 +0000.