4 ms·

Shouldn’t there be a “with existing vaccines” be attached to that? Delta was particularly infectious due to some mutations, but are those mutations antithetica

Shouldn’t there be a “with existing vaccines” be attached to that? Delta was particularly infectious due to some mutations, but are those mutations antithetical in some way to antibody production? Why can’t b-cells just update their response and block that pathway with a new vaccine? My understanding is this was always expected to be whack a mole with the virus anyway. All other endemic coronavirus reinfect people.

wonderwonder 5y ago
We have 45% of Americans refusing to get a vaccine now, imagine the push back if we are attempting to get people to take a new one every 6 months. I don't have a better answer I just know that absolute chaos is down that road.
- anonuser123456 5y ago
  I don’t think it’s that bad. Remember that children < 12 still can’t get it, which is a good chunk of people. Also, some people are not antivax, they are afraid of new mRNA technology. When the technology has had more time to bake, they will feel more comfortable. Finally, Novavax will be coming online soon. That should help with some of the mRNA skeptics.
  - eigen 5y ago
    > Also, some people are not antivax, they are afraid of new mRNA technology. then they can get the Janssen (aka Johnson & Johnson) vaccine which is not based on mRNA but an Adenovirus vector.
    - halfjoking 5y ago
      It’s viral vector which isn’t a traditional vaccine. Viral vector has only been used before for Ebola. All US vaccines execute custom RNA code that was spliced from the real virus. Viral vector just gets that code in the cell by a different method.
    - 015a 5y ago
      Theoretically, though its far-and-away the most media maligned vaccine, and many clinics have ceased carrying it (I specifically have close contact with a few pharmacists who run rural CVS pharmacies; they sent their entire stock of J&J back, and regional has stopped sending more. its all mRNA).
shusaku 5y ago
I can’t read the article because of the pay wall. But the claims I’ve seen elsewhere basically say even with a perfect vaccine, you’d need something like 90% coverage to try and snuff out delta with vaccines alone because it is so incredibly contagious. So to a certain extent you can’t just fix the problem with a new vaccine.
- MereInterest 5y ago
  To my understanding, that's correct. The R0 of the initial strain was somewhere around 2-3. For every infected individual, 2-3 additional individuals were infected. For the delta variant, R0 is around 8-9. In order to get herd immunity, `R0 * vaccination_rate * vaccine_effectiveness` must be less than 1. Even if a new vaccine can reach the same 95% rate as the original vaccine had on the original strain, the increase of R0 raises the necessary vaccination rate from ~65% to ~85%. That's not to say that it's impossible. Chicken pox has a similar R0, but universal vaccination has greatly decreased the spread of the disease. At this point, it mainly occurs in small pockets of non-vaccination, and cannot spread significantly into the wider population. But that requires education and popular support, and is where we'll need to focus our efforts next. [0] https://www.cnn.com/2021/07/29/politics/cdc-masks-covid-19-infections/index.html https://www.cnn.com/2021/07/29/politics/cdc-masks-covid-19-i...
jhayward 5y ago
> but are those mutations antithetical in some way to antibody production? The problem Delta presents to antibody-based protection is that there is a several day lag in the body's response to detecting the virus until it produces mass antibodies. If the (small) number of circulating antibodies are overcome by a large viral load, and if the virus becomes transmissible in a shorter time period, it can "get inside the curve" of antibody response and result in a transmissible infection before the host mounts a full response. Delta is apparently a couple of days 'faster' than the previous Alpha strain in getting to the transmissible stage.
- anonuser123456 5y ago
  I see. So the issue isn’t so much a neutralizing antibody mismatch, but rather an antibody production lag in b cells. That makes covid a long run big problem. We’ll have to be repeatedly challenged with the antigen to keep antibody levels high. Kind of a minor inconvenience for some, but a large % of the population will not comply. Edit: It would seem that it is basically speculation at this point. Memory b-cell response effectiveness will depend on the binding affinity of its antibodies. A high binding affinity antibody producing memory cell will much more rapidly mount an effective response than one that must undergo further affinity maturation.
  - jhayward 5y ago
    The role of cellular immunity isn’t as clear. What would probably make a big difference, though, would be mucosal immunity given by a nasal vaccine. Get those antibodies located at the point of infection and they can get to work earlier.

wonderwonder 5y ago

We have 45% of Americans refusing to get a vaccine now, imagine the push back if we are attempting to get people to take a new one every 6 months. I don't have a better answer I just know that absolute chaos is down that road.

anonuser123456 5y ago
I don’t think it’s that bad. Remember that children < 12 still can’t get it, which is a good chunk of people. Also, some people are not antivax, they are afraid of new mRNA technology. When the technology has had more time to bake, they will feel more comfortable. Finally, Novavax will be coming online soon. That should help with some of the mRNA skeptics.
- eigen 5y ago
  > Also, some people are not antivax, they are afraid of new mRNA technology. then they can get the Janssen (aka Johnson & Johnson) vaccine which is not based on mRNA but an Adenovirus vector.
  - halfjoking 5y ago
    It’s viral vector which isn’t a traditional vaccine. Viral vector has only been used before for Ebola. All US vaccines execute custom RNA code that was spliced from the real virus. Viral vector just gets that code in the cell by a different method.
  - 015a 5y ago
    Theoretically, though its far-and-away the most media maligned vaccine, and many clinics have ceased carrying it (I specifically have close contact with a few pharmacists who run rural CVS pharmacies; they sent their entire stock of J&J back, and regional has stopped sending more. its all mRNA).

shusaku 5y ago

I can’t read the article because of the pay wall. But the claims I’ve seen elsewhere basically say even with a perfect vaccine, you’d need something like 90% coverage to try and snuff out delta with vaccines alone because it is so incredibly contagious. So to a certain extent you can’t just fix the problem with a new vaccine.

MereInterest 5y ago
To my understanding, that's correct. The R0 of the initial strain was somewhere around 2-3. For every infected individual, 2-3 additional individuals were infected. For the delta variant, R0 is around 8-9. In order to get herd immunity, `R0 * vaccination_rate * vaccine_effectiveness` must be less than 1. Even if a new vaccine can reach the same 95% rate as the original vaccine had on the original strain, the increase of R0 raises the necessary vaccination rate from ~65% to ~85%. That's not to say that it's impossible. Chicken pox has a similar R0, but universal vaccination has greatly decreased the spread of the disease. At this point, it mainly occurs in small pockets of non-vaccination, and cannot spread significantly into the wider population. But that requires education and popular support, and is where we'll need to focus our efforts next. [0] https://www.cnn.com/2021/07/29/politics/cdc-masks-covid-19-infections/index.html https://www.cnn.com/2021/07/29/politics/cdc-masks-covid-19-i...

jhayward 5y ago

> but are those mutations antithetical in some way to antibody production? The problem Delta presents to antibody-based protection is that there is a several day lag in the body's response to detecting the virus until it produces mass antibodies. If the (small) number of circulating antibodies are overcome by a large viral load, and if the virus becomes transmissible in a shorter time period, it can "get inside the curve" of antibody response and result in a transmissible infection before the host mounts a full response. Delta is apparently a couple of days 'faster' than the previous Alpha strain in getting to the transmissible stage.

anonuser123456 5y ago
I see. So the issue isn’t so much a neutralizing antibody mismatch, but rather an antibody production lag in b cells. That makes covid a long run big problem. We’ll have to be repeatedly challenged with the antigen to keep antibody levels high. Kind of a minor inconvenience for some, but a large % of the population will not comply. Edit: It would seem that it is basically speculation at this point. Memory b-cell response effectiveness will depend on the binding affinity of its antibodies. A high binding affinity antibody producing memory cell will much more rapidly mount an effective response than one that must undergo further affinity maturation.
- jhayward 5y ago
  The role of cellular immunity isn’t as clear. What would probably make a big difference, though, would be mucosal immunity given by a nasal vaccine. Get those antibodies located at the point of infection and they can get to work earlier.