Re:Israel data reportedly shows efficacy drop of Pfizer-BioN...
by lamontcg on Tuesday July 06, 2021 @12:41PM
(#27750932)
Yes, escape from circulating neutralizing antibodies (so the virus is able to infect you and replicate) is one thing.
Escape from CD4+ T-cells is another thing (the dreaded "reset to 2019" fear).
And the 1918 H1N1 influenza circulated as the only form of seasonal influenza until 1957 (when it was displaced by H2N2 which later became H2N3). From 1957 to 2009 H1N1 mutated in swine. After 50 years of mutating in probably billions of pigs the H1 envelope protein jumped back to humans in 2009. Since old people had pretty universally been exposed to pre-1957 H1N1 they had cross reactive partial immunity from T-cells that still recognized the H1 envelope protein and that pandemic fizzled.
If you can't escape CD4+ T-cells after 50 years of mutating in pigs, I don't think that this coronavirus is going to be able to escape them in a year or two.
Also at some point to achieve escape from neutralizing antibodies this virus is likely going to have to start making "choices" which make it less virulent.
A decline in vaccine efficacy against delta could also indicate that the enhanced transmissibility of delta comes through partial vaccine/immune escape and not through ratcheting up R0/Rt (which would be more consistent with reports that it isn't more lethal / doesn't have higher viral loads, since those switches are all likely to move together).
Escape from CD4+ T-cells is another thing (the dreaded "reset to 2019" fear).
And the 1918 H1N1 influenza circulated as the only form of seasonal influenza until 1957 (when it was displaced by H2N2 which later became H2N3). From 1957 to 2009 H1N1 mutated in swine. After 50 years of mutating in probably billions of pigs the H1 envelope protein jumped back to humans in 2009. Since old people had pretty universally been exposed to pre-1957 H1N1 they had cross reactive partial immunity from T-cells that still recognized the H1 envelope protein and that pandemic fizzled.
If you can't escape CD4+ T-cells after 50 years of mutating in pigs, I don't think that this coronavirus is going to be able to escape them in a year or two.
Also at some point to achieve escape from neutralizing antibodies this virus is likely going to have to start making "choices" which make it less virulent.
A decline in vaccine efficacy against delta could also indicate that the enhanced transmissibility of delta comes through partial vaccine/immune escape and not through ratcheting up R0/Rt (which would be more consistent with reports that it isn't more lethal / doesn't have higher viral loads, since those switches are all likely to move together).