Important
This virus is not happening in a vacuum where no information existed previously
On Immunity, On testing, On serology, On transmission, On masks, On treatments...
We must stop this narrative that we know nothing of this virus until we learn it anew - again.
1/
This virus is not happening in a vacuum where no information existed previously
On Immunity, On testing, On serology, On transmission, On masks, On treatments...
We must stop this narrative that we know nothing of this virus until we learn it anew - again.
1/
The constant drum beat of “we do not know that yet” is tiring.
We KNOW SO MUCH! about SARS-CoV-2 and COVID-19. We knew it before this virus was ever discovered!
We’ve watched since January with study after study reaffirming out expectations of this virus in SO MANY WAYS.
2/
We KNOW SO MUCH! about SARS-CoV-2 and COVID-19. We knew it before this virus was ever discovered!
We’ve watched since January with study after study reaffirming out expectations of this virus in SO MANY WAYS.
2/
In many we ways we got lucky on this front.
Take HIV for ex. HIV was a new virus for which we generally did have to rewrite the text book
But this virus is different from HIV in that it is behaving in almost all ways per the “textbook”.
3/
Take HIV for ex. HIV was a new virus for which we generally did have to rewrite the text book
But this virus is different from HIV in that it is behaving in almost all ways per the “textbook”.
3/
1) Transmission. We knew that this was a transmissible respiratory virus, yet when the virus began transmitting internationally we said we weren’t sure if it would become global.
Of course it would - esp bc in a few weeks it had already transmitted to many countries in Asia
4/
Of course it would - esp bc in a few weeks it had already transmitted to many countries in Asia
4/
2) Transmission
We knew this is a respiratory virus and yet we said we didn’t have enough information to know if masks help or hinder
This was always ridiculous
Yes there were reasons (i.e. conserving PPE), but stating that we didn’t know enough shouldn’t have happened
5/
We knew this is a respiratory virus and yet we said we didn’t have enough information to know if masks help or hinder
This was always ridiculous
Yes there were reasons (i.e. conserving PPE), but stating that we didn’t know enough shouldn’t have happened
5/
3) Immunity:
We know MUCH about viral immunology. When antibodies started to be observed to wane we said this is an other worldly virus and though we must learn everything about it anew. But not so, it serves as a textbook example of immunity to an acute respiratory virus.
6/
We know MUCH about viral immunology. When antibodies started to be observed to wane we said this is an other worldly virus and though we must learn everything about it anew. But not so, it serves as a textbook example of immunity to an acute respiratory virus.
6/
3) Immunity cont’d:
Antibodies go high w primary infection and wane quickly. We know this. Yet it led to massive confusion/concern. People like @VirusesImmunity luckily chimed in to remind that this is normal and @apoorva_nyc wrote a nice about it
nytimes.com/2020/07/26/hea…
7/
Antibodies go high w primary infection and wane quickly. We know this. Yet it led to massive confusion/concern. People like @VirusesImmunity luckily chimed in to remind that this is normal and @apoorva_nyc wrote a nice about it
nytimes.com/2020/07/26/hea…
7/
3) Immunity Cont’d
Knowledge of immunity is accelerating b/c of this virus, yes. The important point is that this virus is not in isolation.
It fits in most ways what we expect / know already. We dont need entirely new empirical immunological evidence for every assertion.
8/
Knowledge of immunity is accelerating b/c of this virus, yes. The important point is that this virus is not in isolation.
It fits in most ways what we expect / know already. We dont need entirely new empirical immunological evidence for every assertion.
8/
4) Testing and transmissible virus
We’ve seen major confusion about PCR, role of Ct values, limitations of PCR and antigen tests, and whether tests can help understand infection status of people.
9/
We’ve seen major confusion about PCR, role of Ct values, limitations of PCR and antigen tests, and whether tests can help understand infection status of people.
9/
Over and over people say we don’t yet know enough to know about how to use Ct values to help determine transmissibility.
But we do! We know so much and have known so much. Ie. We know low Ct values mean likely transmissible. We know that high Ct values mean low viral loads.
10/
But we do! We know so much and have known so much. Ie. We know low Ct values mean likely transmissible. We know that high Ct values mean low viral loads.
10/
At the very least on this front we can use a low Ct value to say “this person definitely has a high viral load” because a bad swab isn’t going to add virus to the test. The other direction, not as clear. But this point need not be in question.
11/
11/
We know how viruses like this grow. Did we know the precise kinetics... no. But we know viruses like this grow exponentially once they take off and then slow down/get cleared.
So we didn’t need all of the empirical evidence to have a very good idea of viral trajectories.
12/
So we didn’t need all of the empirical evidence to have a very good idea of viral trajectories.
12/
5) Seasonality:
This is last point. I recognize we haven’t been w this virus for a full year and its not endemic- so hard to know if it’s seasonal. But we know so much about it already from its closest neighbors... it’s reasonable to make the leap that it’s likely seasonal
13/
This is last point. I recognize we haven’t been w this virus for a full year and its not endemic- so hard to know if it’s seasonal. But we know so much about it already from its closest neighbors... it’s reasonable to make the leap that it’s likely seasonal
13/
These leaps in these areas aren’t guesses. They are part assumptions but usually w clear cut scientifically defined aspects of viruses like this that enable us to combine complex concepts/data and develop pictures of a virus like this before all of the empirical data exists
14/
14/
When we can obtain the empirical data, great.
But by going back to first principles about viral replication, cell biology, immunity, transmission, droplets, pandemic spread, etc we often can infer a tremendous amount despite highly incomplete SARS-CoV-2 specific data.
15/
But by going back to first principles about viral replication, cell biology, immunity, transmission, droplets, pandemic spread, etc we often can infer a tremendous amount despite highly incomplete SARS-CoV-2 specific data.
15/
To sum
I hope that in this pandemic when the pace of necessary forward movement outstrips pace of data collection, we can recognize how much we already know
I am still looking for major aspects of this virus that do not fit the textbook. But they arise only very rarely.
I hope that in this pandemic when the pace of necessary forward movement outstrips pace of data collection, we can recognize how much we already know
I am still looking for major aspects of this virus that do not fit the textbook. But they arise only very rarely.
Extras
See this wonderful comment/review by @baumgarth @deeptabhattacha and their team on this very issue relating to immunity and sticking to the known knowns. This is a terrific work!
jimmunol.org/content/early/…
See this wonderful comment/review by @baumgarth @deeptabhattacha and their team on this very issue relating to immunity and sticking to the known knowns. This is a terrific work!
jimmunol.org/content/early/…
Extra
This on what we knew about the likely limits of contact tracing when many transmission chains exist, the limits of PCR based testing and the potential need/utility for rapid tests as countermeasures.
This on what we knew about the likely limits of contact tracing when many transmission chains exist, the limits of PCR based testing and the potential need/utility for rapid tests as countermeasures.
https://twitter.com/RanuDhillon/status/1315883920106291200
Here is another. We discussed back in March the implications of and likelihood that kids were silent spreaders. We never published this formally. Probably should have...
dash.harvard.edu/handle/1/42639…
dash.harvard.edu/handle/1/42639…
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