Vaccine News: Cambridge Study Shows That Pfizer-BioNTech Vaccine Exhibits Reduced Neutralization Potential Against SARS-Cov-2 B.1.1.7 Variant!
: A new research by scientists from Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID)-University of Cambridge, University College London, University of Kent and Addenbrookes Hospital-UK shows that the Pfizer-BioNTech vaccine exhibits reduced neutralization potential against SARS-CoV-2 B.1.1.7 variant.
The new study findings contradicts Pfizer’s own study and also statements by a lots of fraudulent ‘experts’ and journalists who in the past week have been reporting that the B.1.1.7 variant is not affected by the current COVID-19 vaccines.
SARS-CoV-2 transmission is uncontrolled in many parts of the world, compounded in some areas by higher transmission potential of the B1.1.7 variant now seen in over 60 countries.
To make things worse, many countries are extending the interval between doses of vaccine in order to expand vaccine coverage. It is unclear whether real world neutralizing antibody titres will follow those in clinical trials, particularly in elderly persons, and how this will be impacted by mutations in strains such as B1.1.7.
In this study the research team tested immune responses in patients 3 weeks following the first dose of the Pfizer BioNTech vaccine BNT162b2. They also tested neutralizing antibody responses against pseudoviruses expressing wild type Spike proteins or expressing 3 key mutations present in B.1.1.7 (deletion 69/70, N501Y, A570D). IgG Spike antibody titres correlated well with neutralization.
The team observed a range of neutralization titres against wild type, with geometric mean titre (GMT) of 24. The vaccine sera exhibited a range of inhibitory dilutions giving 50% neutralization (ID50) from 1:4 for 50% neutralization as compared to those under 80 years old (8/15 versus 8/8 P=0.052) after the first dose. Neutralization titres were not significantly impacted by the combination of three Spike mutations tested, but were reduced against the full set of Spike mutations present in the B.1.1.7 variant.
The highest fold change was approximately 6 and the median fold change for the B.1.1.7 variant versus wild type was 3.85 (IQR 2.68-5.28).
The study findings were published on a preprint server and are currently being peer reviewed. https://www.medrxiv.org/content/10.1101/2021.01.19.21249840v1
The study team conducted the study to observe the efficacy of the Pfizer-BioNTech COVID-19 vaccine BNT162b2 against the new variant of SARS-CoV-2, the agent that causes the COVID-19 disease.
This new B.1.1.7 variant, which has higher transmission potential than previous SARS-CoV-2 strains, recently emerged in the UK, South Africa and Brazil and has now been identified in more than 60 countries.
The sudden emergence of B.1.1.7 has triggered concerns over whether the vaccines that are currently being rolled out in an effort to control the COVID-19 pandemic will still be effective against SARS-CoV-2.
Dr Ravindra Gupta from the Cambridge Institute for Therapeutic Immunology and Infectious Diseases-University of Cambridge and his fellow colleagues have demonstrated evidence of a r
educed antibody response against the B.1.1.7 mutant among individuals (aged between 64 and 85) three weeks after they received the first dose of the Pfizer BioNTech vaccine BNT162b.
The study team says the reductions were expected.
The team however said that nevertheless, “further work is needed to establish the impact of these observations on real-life vaccine efficacy.”
From the early stages of the COVID-19 outbreak that began in Wuhan, China, in late 2019, the rapid spread of SARS-CoV-2 has culminated in a global pandemic that has had scientists racing to develop vaccines against the causative agent SARS-CoV-2.
The rather rapid and unprecedented scientific response to this global challenge has led to three vaccines now being licensed for use, namely the Pfizer BioNTech BNT162b2 vaccine, the Moderna mRNA-1273 vaccine, and the Oxford-AstraZeneca ChAdOx1 nCoV-19 vaccine.
All these vaccines all target a protein expressed on the surface of SARS-CoV-2 called spike, which is the main structure the virus uses to bind to and infect the cell.
But it should be noted that these vaccines were designed against the Wuhan strain isolated in 2019.
However since then, the virus has evolved to optimize its infectivity and evade being targeted by drugs and the immune system.
Currently SARS-CoV-2 transmission has been confounded in many areas of the world by the recently emerged B1.1.7 variant, which has now been identified in over 60 countries.
Alarms are growing as to whether the Pfizer BioNTech, Moderna, and Oxford-AstraZeneca vaccines will be effective against this new variant.
Also as vaccine supply is limited, and many governments have had to extend the interval time between first and second doses in order to expand vaccine coverage.
Dr Gupta told Thailand Medical News, “Information on vaccine-elicited responses in real-world settings outside of highly selective clinical trials is important. It is unclear whether real-world neutralizing antibody titers will follow those in clinical trials, particularly in elderly persons, and how this will be impacted by mutations in strains such as B1.1.7.”
The study team assessed immune responses induced three weeks following one dose of the Pfizer BioNTech vaccine BNT162b2 vaccine among 23 individuals who have received the first dose as part of vaccine rollout in the UK.
The researchers also tested neutralizing antibody responses against pseudoviruses engineered to express wild-type spike protein or the three key mutations present in B.1.1.7 (deletion 69/70, N501Y, A570D). In addition, the team tested a panel of sera from eleven individuals who had recovered from SARS-CoV-2 infection.
Importantly the study cohort had a median age of over 80 (82 years), in line with the targeting of this age group in the initial UK vaccine rollout.
The study team reported that titers of anti-spike immunoglobulin G (IgG) correlated well with neutralization responses.
The study findings showed that ant-spike IgG antibody titers were much higher among vaccinated individuals than among healthy controls and were similar to those seen among recovered individuals.
But there was an almost 100-fold variation in IgG responses among the vaccinated participants. Those older than 80 years exhibited significantly reduced IgG responses and lower neutralization potency than those younger than 80.
The study team said, “This may or may not be compensated for by the second dose and it will be important to follow all participants over the following months for measurement of neutralization activity as well as data on re-infection.”
The three B.1.1.7 mutations in spike did not significantly impact neutralization titers among recovered individuals or people who had been vaccinated.
The study team next engineered a pseudovirus to express spike protein that included the full set of mutations present in the B.1.1.7 variant (del69/70, del 144/145, N501Y, A570D, P681H, T716I, S982A, D1118H).
Significantly when sera were tested against this full set of B.1.1.7 spike mutations, neutralization titers were reduced among the vaccinated individuals.
It was found that among 15 individuals who had exhibited neutralization activity three weeks following vaccination, 10 showed evidence of a reduced antibody response against the B.1.1.7 mutant.
On the whole, reduction in efficacy was less than 3-fold, while the most significant reduction was around 6-fold, and the median reduction was 3.85-fold.
The study team said, “These changes are what we expected to see given the mutational profiles.”
They warned further research is needed to investigate the impact of these observations on real-life vaccine efficacy.
The study team said, “Other variants also need to be tested against vaccine sera, some with more concerning mutations such as E484K and K417N that have been shown to impact neutralization by monoclonal antibodies or convalescent sera.”
It should be noted that another recent study also showed that the B.1.1.7 variant could escape neutralization by certain monoclonal antibodies. https://www.biorxiv.org/content/10.1101/2021.01.15.426849v1
In the meanwhile the EU is current sounding high alert warnings against the new variants including the B.1.1.7 https://www.ecdc.europa.eu/en/publications-data/covid-19-risk-assessment-spread-new-variants-concern-eueea-first-update
While all this new studies and warnings are emerging, we still have so called ‘experts’ and ‘medical journalists ‘saying that the current COVID-19 vaccines are not affected by variants like the B.1.1.7. https://www.usnews.com/news/health-news/articles/2021-01-21/will-vaccines-work-against-the-new-coronavirus-variants
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