COVID-19 Science News: Week Starting 08/06

4 min readJun 14, 2020

Disease & Infection

The WHO made headlines with their statements about asymptomatic transmission recently. [1] They have clarified and corrected their statements, however the main points are worth reiterating. [2]

There is a distinction between asymptomatic and presymptomatic patients. The former never develop symptoms; the latter term is used to describe infectious patients who infect others and go on to develop symptoms later.

A meta-analysis conducted by researchers in Australia determined that only five (of 571) published studies appropriately screened for truly asymptomatic patients. Their pooled analysis put the proportion of asymptomatic cases at 16 % (albeit with quite wide confidence intervals) and it tentatively concludes that these patients may be marginally less infectious than symptomatic or pre-symptomatic ones. [3]

It is well established that presymptomatic patients shed large amounts of virus. [4] It is presumed that a similar situation occurs with asymptomatic cases, as viral loads are similar to presymptomatic patients. [5] This is hard to study, as it is inherently difficult to identify and reliably trace these individuals. [6] There are many hypotheses as to why some people are asymptomatic, but none have any solid evidence behind them yet.

A great infographic for the disease progression has been created by Prof. David Liu from Harvard. [7]

COVID-19 Disease Timeline. Credit: Prof. David R. Liu, Professor of Chemistry and Chemical Biology at Harvard University

A quick note, a study in PNAS that claims to identify airborne transmission as the main cause of spread and that masks are the most effective measure taken is heavily flawed and is on track for retraction. [8,9]
Author’s note: The findings are not adequately justified by the authors but this does not mean the opposite is true!

Two separate analyses (Germany, US) provide further support for the use of masks. The exact % reduction of infections due to their use is not precisely defined, however they are deemed to be certainly effective. Non-surgical masks and simple face coverings also appear effective at preventing infectious individuals from infecting others. [10,11]

A preprint describing the development of Biovacc-19’s SARS-CoV-2 vaccine has made headlines recently as alleged evidence of the synthetic origin of the virus. [12,13] To the best of my reading, this document makes no such claim. Regardless, there are several lines of strong evidence indicating that SARS-CoV-2 is a virus arising from combination of viruses present in bats and pangolins. [14–16]

Genomic analysis of virus samples in California demonstrates how international and interstate travel spreads the virus over vast distances. [17] A large virus genome sequencing effort is underway in the UK, with over 7,000 genomes sequenced so far in only 4 weeks. [18]

Vaccine News

Moderna has released animal data for their mRNA vaccine. Only mice data shown, quite some noise in some data. The absence of monkeys or other primates being challenged with virus is curious. Phase II has begun for this vaccine already, Phase I is completed but the data have still not been released. [19]

Various reports on other vaccines have also been circulating, but no publications containing hard data. [20]

Antibodies & Immunity

Antibody testing on 2766 members of the general population in the Swiss canton of Geneva shows that at most ~10 % of the people tested show antibodies against SARS-CoV-2. This is despite the region being one of the hardest hit, indicating the effectiveness of the measures taken. These same data suggest that 11–12 infections occurred in the community per confirmed case. This also means that a second wave of infection is extremely likely. [21]

Multiple companies have started dosing patients with their anti-SARS-CoV-2 monoclonal antibodies these past days. Eli Lilly, Junshi Biosciences and Regeneron are among those already in trials; Vir Biotechnology and GSK are expected to join them soon. [22]

Other Therapies

A receptor (Neuropilin 1) other than the now-famous ACE2 seems to be associated with SARS-CoV-2 infection. The study suggests that this could be an additional potential therapeutic target. [23]

The role of interferons in lower respiratory infections (COVID-19 included) reveals a dual role, protective in some cases and exacerbating in others. These studies highlight the importance of timing in the administration of therapeutics for patients, specifically that the use of interferons late in disease progression may be detrimental. [24–26]

The now-infamous Dr Raoult has published a (not yet peer reviewed) review of studies on hydroxychloroquine. As with his other publications on the issue, many concerns are raised; chief among them the fact that the Editor-in-Chief of the journal the review is set to be published in works for Dr Raoult. [27–29]

References

COVID-19 Science News: Week Starting 08/06

Written by Michael Bogdos