I am getting lots of questions if my pre-print about some #SARSCoV2 sequences that were removed from Sequence Read Archive tell us anything about lab accident versus natural zoonosis.
I posted summary of pre-print below, but did not directly address this point explicitly (1/n)
The answer is NO. The people using it to strongly support either argument are those that have become so emotionally invested in their opinion that they have lost the ability to analyze anything objectively outside of the framework of that argument. (2/n)
What the pre-print does imply is as follows:
First, there may be additional relevant data in obscure locations that aren't the places where we are accustomed to looking (e.g., on the Google Cloud, in table 1 of a paper on diagnostics, etc):
Second, in my opinion, anybody doing phylogenetics on early #SARSCoV2 sequences from China should spend as much time on metadata as algorithms. Sequences in databases may be non-representative. Sequences collected in Guangdong might be from infections from Wuhan. Etc. (4/n)
Third, preprint provides modestly more evidence for progenitor being in clade A (not market clade), & substantially more evidence it might have T at site 29095. However, current inferences are likely based on incomplete data. @sergeilkp says it best:
In new study led by @bblarsen1 in collab w @veeslerlab @VUMC_Vaccines we map functional & antigenic landscape of Nipah virus receptor binding protein (RBP)
Results elucidate constraints on RBP function & provide insight re protein’s evolutionary potentialbiorxiv.org/content/10.110…
Nipah is bat virus that sporadically infects humans w high (~70%) fatality rate. Has been limited human transmission
Like other paramyxoviruses, Nipah uses two proteins to enter cells: RBP binds receptor & then triggers fusion (F) protein by process that is not fully understood
RBP forms tetramer in which 4 constituent monomers (which are all identical in sequence) adopt 3 distinct conformations
RBP binds to two receptors, EFNB2 & EFNB3
RBP’s affinity for EFNB2 is very high (~0.1 nM, over an order of magnitude higher than SARSCoV2’s affinity for ACE2)
Over 4 yrs after being first to publicly release SARS-CoV-2 genome, Yong-Zhen Zhang just published large set of viral seqs from first stage of COVID-19 outbreak in China
Zhang recruited nearly all COVID-19 patients hospitalized at Shanghai Public Health Center in first 2/3 (Jan-Sep) of 2020.
The largest source of Shanghai patients in Jan/Feb 2020 was imported cases from Wuhan or elsewhere in Hubei, thereby providing window into Wuhan outbreak.
Overall, Zhang obtained 343 near-full-length SARS-CoV-2 sequences from 226 distinct patients, including 133 sequences from samples collected no later than Feb-15-2020.
A phylogenetic tree showing these sequences is below.
In new study led by Caleb Carr & @khdcrawford, we measure how all mutation to Lassa virus glycoprotein complex (GPC) affect cell entry & antibody escape
Results show how prospective assessment of effects of mutations can inform design of countermeasures biorxiv.org/content/10.110…
As background, Lassa virus causes of thousands of deaths each year, mostly from spillovers from its rodent host, but there is occasional human-to-human transmission.
Lassa is biosafety-level-4 priority pathogen, & efforts are underway to develop vaccines & antibody therapeutics.
We used pseudovirus deep mutational scanning to study effects of nearly all 9,820 amino-acid mutations to Lassa’s GPC at biosafety-level-2 by making genotype-phenotype linked libraries of lentiviral pseudotypes blog.addgene.org/viral-vectors-…
Here is my brief analysis of Dec-28-2019 SARSCoV2 submission to Genbank.
This analysis supports my conclusion to WSJ () that this submission does not tell origin of virus, but does show sequence known to Chinese Academy of Sciences weeks before released wsj.com/politics/natio…
Here is link to my full analysis:
See also images of the same posted below (although it's probably just easier to click on link above and read HTML). github.com/jbloom/SARS2_2…
I also don't think Genbank/NCBI could have reasonably known at time that this sequence was so valuable given that Chinese govt did not announce they had sequence or had submitted it, and Genbank receives vast numbers of submissions.
As background, human influenza constantly evolving. So people exposed to different strains, depending on their age & idiosyncratic history of infection/vaccination.
Different exposure histories cause people to make antibodies w different specificities