Cases surge in most vaccinated nation on Earth (Seychelles)
The Seychelles is the most vaccinated nation on Earth. But Covid has surged
[Media report.] The Seychelles […] can boast having the highest share of people vaccinated against Covid-19 anywhere in the world [~62%], above Israel and the U.K. On Monday, the Seychelles’ health ministry reported a steep rise in the number of cases. From 120 new cases reported on April 30, a week later over 300 cases per day were recorded on May 7 and May 8, respectively. The ministry noted that, of the patients requiring hospital treatment, 80% had not been vaccinated and tended to be people with co-morbidities. It added that “almost all” of the critical and severe cases requiring intensive care treatment had not been vaccinated either. To date, none of the patients who have died with Covid-19 have been fully vaccinated, it said.
WHO designates B.1.617 [Indian] variant as a variant of concern
[Via Johns Hopkins.] In this week’s WHO epidemiological update, the WHO designated the B.1.617 variant as a variant of concern (VOC). The WHO Virus Evolution Working Group has determined that viruses within the B.1.617 lineage, which contains three sublineages, to be VOCs because they appear to be more transmissible, less responsive to some treatments, and less susceptible to antibody neutralization. Additionally, animal models show the B.1.617 variant may cause more severe disease.
CDC says 28 blood clot cases, 3 deaths may be linked to J&J Covid vaccine
[Media report.] The median age of the patients was 40, ranging from 18 to 59 years old. Women who were 30 to 39 years old accounted for the biggest risk group.
Feasibility of large-scale population testing for SARS-CoV-2 detection by self-testing at home
We evaluated the applicability of a self-testing strategy for SARS-CoV2 in a population-based, cross-sectional study in Cantabria, Spain, between April and May 2020. Participants received the necessary material for the self-collection of blood and performance of a rapid antibody test using lateral flow immunoassay at home without the supervision of healthcare personnel. A total of 1,022 participants were enrolled. Most participants correctly performed the COVID-19 self-test the first time (91.3% [95% CI 89.4–92.9]). Prevalence of IgG antibodies against SARS-CoV2 for subjects with a valid rapid test result was 3.1% (95% CI 2.2–4.4), similar to the seroprevalence result obtained using a conventional approach carried out by healthcare professionals. COVID-19 self-testing should be considered as a screening tool.
The epidemiological impact of the NHS COVID-19 App
Here we investigated the impact of the NHS COVID-19 app for England and Wales, from its launch on 24 September 2020 through to the end of December 2020. It was used regularly by approximately 16.5 million users (28% of the total population), and sent approximately 1.7 million exposure notifications: 4.4 per index case consenting to contact tracing. We estimated that the fraction of app-notified individuals subsequently showing symptoms and testing positive (the secondary attack rate, SAR) was 6.0%, comparable to the SAR for manually traced close contacts. We estimated the number of cases averted by the app using two complementary approaches. Modelling based on the notifications and SAR gave 284,000 (108,000-450,000), and statistical comparison of matched neighbouring local authorities gave 594,000 (317,000-914,000). Roughly one case was averted for each case consenting to notification of their contacts. We estimated that for every percentage point increase in app users, the number of cases can be reduced by 0.8% (modelling) or 2.3% (statistical analysis). These findings provide evidence for continued development and deployment of such apps.