22 Jan 2021 Episode 103 News on variants and vaccines

Fri, 01/22/2021 - 21:55

Dear colleagues,

 

My next episode (after this one) will be on pathogenesis and requires some more time.

For now just an update on the spread of the variants and their susceptibility to vaccine-induced antibodies: reason for concern, but not for panic;

Ep 103-1a: Further evidence that the “British variant” will most probably be susceptible towards the present vaccination with Pfizer-BioNTech. In this study a “pseudovirus” with the full B117 spike was used and sera from people three weeks after the second dose vaccination

Ep 103-1b: Another study used sera from people who had received the first dose 3 weeks before. Although a combination of 3 mutations (deletion 69/70, N501Y, A570D) has little impact on neutralization sensitivity of these sera, replacing the WT spike with the full B117 spike did lower the neutralization sensitivity slightly.  Not unexpectedly, individuals over 80 also tended to have lower titers of neutralizing antibodies

The next step is to prove that these sera also neutralize the full infectious virus, but the chances are high.  

I could not find an official paper yet on the increased pathogenicity of B117 (which is in the media today.

Ep103-2: Confirmation that the D614G variant is indeed more infectious, produces a higher viral load and is more found in younger populations, but there is NO increased mortality.  I could not find evidence that this G variant is equally susceptible to vaccination than the D variant.

Ep 103-3: The first signs of effectivity of the Pfizer vaccine emerge in Israel: In a preliminary analysis of 200,000 people older than 60 who received the vaccine, compared with a matched group of 200,000 who did not, researchers found that the chances of testing positive for the virus were 33% lower two weeks after the first injection. Clearly, these results have not yet been formally published.  

Ep 103- 4: As could be expected, the South-African variant is also spreading over the world.  I could not find evidence on it’s susceptibility to neutralization by sera from vaccinated people.

Ep 103-5: A “journalist” update on the Brazilian P1 strain: it is spreading very quickly in Manaus, but that is probably also due to the non-compliance with non-pharmacological measures, which are  being discouraged by the Bolsonaro “afficionados”. Until now, there is only one documented case of reinfection with the P1 variant, but the question is how well this is monitored

Ep 103-6: More worrying news with regard to the South-African variants. Cele et al show that several convalescent sera from patients who were previously infected with the “regular” SARS-CoV-2  (including D614G) had rather weak neutralizing activity against two full variant viruses (no pseudovirus constructs this time).  

Ep 103-7: Wang et al used sera from fully vaccinated subjects with either Pfizer or Moderna and found a “slight, but significant” reduction in neutralization activity against pseudoviruses that carried E484K or N501Y or the K417N:E484K:N501Y

 

Finally, a call for action in The Lancet: we need to strengthen the non-pharmacological intervention at this stage in a wise and consistent manner!!!

 

Have a nice weekend

 

Guido

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