Three doses of Pfizer vaccine likely to protect against Omicron infection, tests suggest
Initial findings indicate stark reduction in protection against new Covid variant from two vaccine doseshttps://www.theguardian.com/world/2021/dec/08/omicron-can-partially-evade-covid-vaccine-protection-study-finds
Three doses of the Pfizer/BioNTech vaccine are likely to protect against infection with the Omicron variant but two doses may not, according to laboratory data that will increase pressure to speed up booster programmes.
Tests using antibodies in blood samples have given some of the first insights into how far Omicron escapes immunity, showing a stark drop-off in the predicted protection against infection or any type of disease for people who have had two doses. The findings suggest that, for Omicron, Pfizer/BioNTech should now be viewed as a “three-dose vaccine”.
The vaccine makers said they would continue “at full speed” with plans to develop an updated Omicron-based vaccine by March 2022 if needed – and their working presumption is that it will be. Separate results, from preliminary studies by the German Centre for Infection Research, also found significant reductions in antibody potency for the Pfizer/BioNTech, Moderna and Oxford/AstraZeneca vaccines against Omicron.
In the first official briefing from vaccine manufacturers on the likely efficacy of their shots against Omicron, Prof Uğur Şahin, the CEO and co-founder of BioNTech, said on Wednesday: “Individuals who have received two vaccines will most likely not have a significant prevention from infection or any type of disease. We know they will have memory T-cells, which may prevent severe disease.”
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Link to tweet
SARS-CoV-2 Omicron has extensive but incomplete escape of Pfizer BNT162b2 elicited neutralization and requires ACE2 for infection
https://www.ahri.org/wp-content/uploads/2021/12/MEDRXIV-2021-267417v1-Sigal.pdf
raised concerns that, based on the large number of mutations in the spike protein and elsewhere on
the virus (https://covdb.stanford.edu/page/mutation-viewer/#sec_b-1-351), this variant will have
considerable escape from vaccine elicited immunity. Furthermore, several mutations in the receptor
binding domain and S2 are predicted to impact transmissibility and affinity for ACE-2.
Here we investigated whether Omicron escapes antibody neutralization elicited by the Pfizer
BNT162b2 mRNA vaccine and whether the virus still requires binding to the ACE2 receptor to infect
cells. We used an early passage of isolated and sequence confirmed live Omicron virus isolated in
South Africa. We used a human lung cell line clone (H1299-ACE2) engineered to express the ACE2
receptor (2) to both isolate the virus and test neutralization. We also tested growth in the parental
H1299 which do not overexpress ACE2 and are not appreciably infectable with SARS-CoV-2 (Fig S1).
The H1299-ACE2 cells were similar to Vero-E6 in titer dependent focus formation, but were
considerably more sensitive (Fig S2).
We observed that Omicron infected the ACE2-expressing cells in a concentration dependent manner
but did not infect the parental H1299 cells, indicating that ACE2 is required for Omicron entry (Fig.
1A). We then tested the ability of plasma from BNT162b2 vaccinated study participants to neutralize
Omicron versus ancestral D614G virus in a live virus neutralization assay. We tested 14 plasma
samples from 12 participants (Table S1), with 6 having no previous record of SARS-CoV-2 infection
nor detectable nucleocapsid antibodies indicative of previous infection. For two of these
participants, we used samples from two timepoints. The remaining 6 participants had a record of
previous infection in the first SARS-CoV-2 infection wave in South Africa where infection was with
ancestral D614G virus (Table S1). Geometric mean titer (GMT) FRNT50 (inverse of the plasma
dilution required for 50% reduction in infection foci number) was 1321 for D614G. These samples
therefore had very strong neutralization of D614G virus, consistent with sampling soon after
vaccination. GMT FRNT50 for the same samples was 32 for Omicron, a 41-fold decline (Fig 1B).
However, the escape was incomplete, with 5 of the participants, all previously infected, showing
relatively high neutralization titers with Omicron.
Beta variant escape from BNT162b2 in a live virus neutralization assay has been reported to be
substantial (3) and our own data confirmed these results (4), with about 3-fold reduction in FRNT50.
The results we present here with Omicron show much more extensive escape. However, escape was
incomplete in participants with higher FRNT50 due to previous infection. Previous infection,
followed by vaccination or booster is likely to increase the neutralization level and likely confer
protection from severe disease in Omicron infection.
Omicron, aka B.1.1.529
https://covdb.stanford.edu/page/mutation-viewer/#omicron
BA.1
Mutations are from Pango-designation issue #361
BA.2
Mutations are from Pango-designation issue #361
= new reply since forum marked as read
if the same (well 6 months on in your case) can be done with 12 year olds.
I also am not a normal example, as all 3 of my jabs (and my wife's as well) were part of an experiment variant-tweaked Moderna trial here in Stockholm.
details here (and IF they make an Omicron variant-tweaked booster (the Delta jab was pre Omicron), we will be getting that 4th jab in March or early April, 2022, as part of the trial, we are true Guinea pigs, lol):
Moderna booster (given at 5 months post 2nd jab) report. Sun Sep 26, 2021
https://upload.democraticunderground.com/100215894665
We finally had a reaction after no effects from either asymptomatic origin-strain Covid back in late April early May 2020, and then 2 South African (Beta) variant-tweaked mRNA-1273.351 Moderna initial jabs (the 2nd one around 5 months back) as part of a trial here in Stockholm.
Thursday we got (as part of an additional, very small experimental trial) jabbed for the 3rd time and this was with the new Moderna mRNA-1273.617 Delta variant tweaked vax (100 µg dosage).
We had almost no reactions to the Beta variant jabs other than sore arms for like 12 hours or so.
Not this time, lolol.
By around 20 00 to 2200 (we got them at 14 00) we were both asking what type of lorry had run us over. Fever (over 100F) chills, headache from hell, and night sweats all night long, plus sore arms (the same intensity as the first two). Friday we were still not 100% recovered but had far less symptoms and no fever. Sore arms were gone by nightfall Friday. By this morning (Saturday) most all symptoms have disappeared for both me and wifey.
That first night was rough, sickest either of us had been in years tbh, but it came and went fairly quickly. I had the added 'pleasure' of some serious PMS as well (non vax related of course).
The doctors warned us to expect a heavy duty reaction based off a similar trial already running in the US.
I will post again when we get the results of a blood draw on October 7th. Moderna is no longer going to run with the beta variant specific only trials, at least not here in Sweden.
They also are testing a new multivalent vax, mRNA-1273.213, a candidate combining the Beta-specific and Delta-specific candidates. Our results (because we got both as single variant vaxes, so a similar profile) will be compared to that one.
That mRNA-1273.213 vax is one of the most likely variant-tweaked vaccines that could be made available to the general public (or so our doctors say, and of course they are speaking about Sweden, they would not make statements about the US). They also said that Pfizer (actually it is their partner, in Germany, BioNTech, that is running point on this) is already in trials with Delta variant (and all other variants as well, the same as Moderna os doing) tweaked vaccines too. Both Moderna and BioNTech can switch variant types on vaccines in less than 4 weeks. It is amazing technology.
