Dr. Boarhead’s Summary of Global Updates on the 2019 Novel Coronavirus: 7 February 2021
1. medRxiv:
The antibody response to the first vaccine dose in individuals with pre-existing immunity is equal to or even exceeds the titers found in naïve individuals after the second dose. Changing the policy to give these individuals only one dose of vaccine would not negatively impact on their antibody titers but would spare them from unnecessary pain and free up many urgently needed vaccine doses.
<29 Jan.>
[key info]
For individuals with pre-existing COVID-19 immunity, one shot of vaccine is sufficient.
https://www.medrxiv.org/content/10.1101/2021.01.29.21250653v1
2.
New York Times
:
The number of new average cases in the US was 40% lower on 29 Jan. than at the peak three weeks earlier. Hospitalizations were down significantly from record highs in early Jan. The number of tests per day had also decreased, which could obscure the virus’s true toll, but the positivity rate of those tests had also gone down, indicating that the spread had slowed down.
<31 Jan.>
[key info]
Several indicators show the current downward trend in cases in the US.
https://www.nytimes.com/interactive/2021/01/31/us/coronavirus-cases-hospitalizations-decreasing.html
3.
Lancet Infectious Diseases
:
21,977 adults were randomly assigned to the study of Gam-COVID-Vac (Sputnik V), with 16,501 to the vaccine group and 5,476 to the placebo group. From 21 days after the first dose, 16 (0.1%) of 14,964 participants in the vaccine group and 62 (1.3%) of 4,902 in the placebo group were confirmed to have COVID-19; vaccine efficacy was 91.6%.
<2 Feb.>
[key info]
Sputnik V was 91.6% effective.
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00234-8/fulltext
4.
Lancet
:
Only one-third of COVID-19 cases transmitted the virus to close contacts. Those with a relatively high viral load were much more likely to pass on the virus than were those with a low viral load. Cases were no more likely to transmit the virus if they had a cough.
<2 Feb.>
[key info]
Viral load is more defining than coughing in the possibility of transmission.
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30985-3/fulltext
5.
Nature
:
Low connectivity may be the main driver for prolonged, asynchronous outbreaks in sub-Saharan Africa (SSA) population centers. Some countries show rapid spread between administrative units, while in others connectivity is so low that the outbreak may be over in the administrative unit of the largest size before introductions successfully reach other poorly connected administrative units.
<2 Feb.>
[key info]
Low connectivity may result in asynchronous outbreaks.
https://www.nature.com/articles/s41591-021-01234-8
6.
Lancet
:
Of 16,442 patients enrolled in a study, 2,582 were randomly allocated to receive azithromycin and 5,181 to receive usual care alone. Overall, 561 (22%) patients in the azithromycin group and 1,162 (22%) in the usual care group died within 28 days.
<2 Feb.>
[key info]
Azithromycin might not reduce morality.
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00149-5/fulltext
7.
Journal of the American Medical Association
:
Of the 19,398,384 international travelers who entered China from 16 Apr. to 12 Oct. 2020, 3,103 had SARS-CoV-2 infection. Of all SARS-CoV-2-positive entrants, 1,354 (43.6%) were symptomatic at entry, 137 (4.4%) were pre-symptomatic and categorized as confirmed cases, whereas 1,612 (51.9%) were considered to have asymptomatic infection.
<2 Feb.>
[key info]
About 52% of infected entrants into China were asymptomatic.
https://jamanetwork.com/journals/jama/fullarticle/2775705?resultClick=1
8.
Nature
:
When human β-cells express viral entry proteins, and SARS-CoV-2 infects and replicates in cultured human islets, the infection can reduce the number of insulin-secretory granules in β-cells and impair glucose-stimulated insulin secretion. Therefore, human pancreas is identified as a target of SARS-CoV-2 infection, and β-cell infection can contribute to the metabolic dysregulation observed in COVID-19 patients.
<3 Feb.>
[key info]
Diabetes can arise as a result of SARS-CoV-2-associated β-cell destruction.
https://www.nature.com/articles/s42255-021-00347-1
9.
Science
:
Coronaviruses acquire substitutions more slowly than other RNA viruses, but this slow substitution rate can be overcome by recurrent deletions in the spike glycoprotein. Deletions in recurrent deletion regions (RDRs) confer resistance to neutralizing antibodies. By altering stretches of amino acids, deletions appear to accelerate SARS-CoV-2 antigenic evolution and may, more generally, drive adaptive evolution.
<3 Feb.>
[key info]
Recurrent deletions in the SARS-CoV-2 spike glycoprotein may drive antibody escape.
https://science.sciencemag.org/content/early/2021/02/02/science.abf6950.full
This is issue fifty-eight,
edited on the basis of information from the official websites including but not limited to those of
The World Health Organization,
The European Centre for Disease Prevention and Control,
The Centers for Disease Control and Prevention of the United States of America, &
The Center for Infectious Disease Research and Policy of the University of Minnesota
and from the forums of FluTrackers.com.
This issue is edited by Alex Sun, Dorothy Fang, Dora Zhang, and
Fred Wong,
under the supervision of Dr. Jason Chu and Conch Zhang.
2020 © The Chung Kwong Wui
