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> test asymptomatic people for COVID-19 and then genome sequence the SARS-CoV-2 strain that has infected them with the aim of identifying a virus with mutation(

> test asymptomatic people for COVID-19 and then genome sequence the SARS-CoV-2 strain that has infected them with the aim of identifying a virus with mutation(s) in an essential viral gene(s) But without these essential genes the virus would not multiply / infect people anyway, right? Also, how is it different from inactivated vaccines that are currently being developed ? Also, why cant someone engineer such a virus with appropriate deletions? https://www.cell.com/immunity/fulltext/S1074-7613(20)30120-5#%20 https://www.cell.com/immunity/fulltext/S1074-7613(20)30120-5...

danieltillett 6y ago
1. You are looking for partial deletions of essential genes, not full. Many of these deletions are going to weaken the virus, but not cause the virus to not be able to replicate. 2. An inactivated vaccine will have to be given again and again. A live attenuated vaccine can drive the dangerous strains to extinction. Also attenuated vaccines protect those not vaccinated. 3. In theory you could engineer a virus with deletions, but nobody knows what deletions will work. By using natural deletions you know are mild you get around this problem. It also solves the regulatory issue as you are not going to be able to quickly test a lab made strain.
- buboard 6y ago
  and how would we know that the harmless-virus infection protects against the dangerous strain? are there already databases of sequenced strains? and how would the regulatory aspect work? if the harmless individual is no longer infectious, how would people be infected
  - danieltillett 6y ago
    1. You would check the person’s immune response. With luck they have infect a pool of people in the local area which should give you more data. 2. Yes there are, but we need to look for a quite rare mutant. 3. We would be genome sequencing clinical samples - these would be kept in storage until the data comes back.

danieltillett 6y ago

1. You are looking for partial deletions of essential genes, not full. Many of these deletions are going to weaken the virus, but not cause the virus to not be able to replicate. 2. An inactivated vaccine will have to be given again and again. A live attenuated vaccine can drive the dangerous strains to extinction. Also attenuated vaccines protect those not vaccinated. 3. In theory you could engineer a virus with deletions, but nobody knows what deletions will work. By using natural deletions you know are mild you get around this problem. It also solves the regulatory issue as you are not going to be able to quickly test a lab made strain.

buboard 6y ago
and how would we know that the harmless-virus infection protects against the dangerous strain? are there already databases of sequenced strains? and how would the regulatory aspect work? if the harmless individual is no longer infectious, how would people be infected
- danieltillett 6y ago
  1. You would check the person’s immune response. With luck they have infect a pool of people in the local area which should give you more data. 2. Yes there are, but we need to look for a quite rare mutant. 3. We would be genome sequencing clinical samples - these would be kept in storage until the data comes back.