Scientists identify key differences in immune responses to the AstraZeneca and Pfizer vaccines.
A recent study conducted by a team from SAHMRI and Flinders University in Australia has revealed significant variations in the way the AstraZeneca and Pfizer COVID-19 vaccines affect the immune system. The findings, published in Cell Reports Medicine, are part of the COVID-19 Vaccine Immune Responses Study (COVIRS) and were based on the analysis of the immune responses of 102 adults of various ages residing in South Australia, where there was no SARS-CoV-2 community transmission at the time of the study.
The participants in the study had their blood samples collected immediately after receiving each dose of either the Oxford/AstraZeneca or Pfizer/BioNTech COVID-19 vaccine, in order to evaluate their early immune response. Further tests were conducted 28 days after each immunization to measure the activity of B and T cells, both of which play a crucial role in the immune response. B cells produce antibodies, while T cells target and eliminate infected cells.
The vaccines are alike in the sense that they induce the immune system to recognize and protect against the SARS-CoV-2 virus, but they differ in how this is achieved. The Pfizer vaccine uses mRNA technology to induce host cells to produce the SARS-CoV-2 Spike protein, while the AstraZeneca vaccine uses a harmless virus (a chimpanzee adenovirus) to encode the Spike protein.
"After the first dose, we were surprised to find the Oxford/AstraZeneca vaccine elicits an unexpected memory-like response in the immune system, recognizing the vaccine as if it's something it's seen before," says Professor Lynn, from the College of Medicine and Public Health at Flinders University.
"This response is targeted against the adenovirus vector in the vaccine, not the Spike protein and the intensity of this response correlates with the expression of proteins that act as a pre-cursor to thrombosis, or blood clotting. While Vaccine-induced immune thrombotic thrombocytopenia (VITT) is an extremely rare side effect associated with the Oxford/AstraZeneca vaccine that none of the participants developed during the study, this research offers a potential explanation for the connection between the Oxford/AstraZeneca vaccine and the cases of VITT that have been reported."
The study also found those who'd only had two doses of the Oxford/AstraZeneca vaccine generally produced lower amounts of antibodies and less of a specialized type of T-cell that helps with antibody production; compared to those who had two doses of the Pfizer/BioNTech vaccine.
However, this was rectified once they had their third booster dose of an mRNA vaccine, illustrating the importance of booster doses. The study added evidence to the notion that COVID-19 vaccines offer some people more effective protection than others.
The reasons for this variability are not well understood, but Professor Lynn says age is a factor, with older people generally having a lower immune response after two doses. Fortunately, a third booster dose was highly effective at overcoming this. Immune responses induced immediately after vaccination predicted the subsequent B and T cell response to the vaccine measured a month later.
"One to two days after initial vaccination we measured gene expression responses in the blood which correlated with adaptive immune responses that mediate protection 28 days later," Professor Lynn says.
A further surprise to researchers was the finding that feeling unwell after a vaccine dose may in fact be linked to its effectiveness.
"People who showed symptoms of fatigue and fever immediately after the third dose were more likely to have better T-cell responses. T-cells play a vital role in vaccine efficacy as they can directly kill viral cells," Professor Lynn said.
Overall, this project has provided important new insights into the early immune responses to these vaccines and offers a greater understanding of how they work to protect against COVID-19.
News
GHCE Concept
From the preface of the book Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artificial Intelligence, Edited by Frank Boehm: Since the publication of my first book (Nanomedical Device and Systems [...]
Human Bodies Are Producing Two Billion Tons of CO2 a Year
A new study reveals that the amount of carbon dioxide produced by human metabolism has increased dramatically over three decades. The carbon dioxide produced by human bodies as they convert food into energy increased [...]
A Hidden DNA Mechanism Could Explain How 20% of Human Cancers Develop
Researchers have identified an unexpected molecular vulnerability in cancers carrying BAF mutations. Mutations found in roughly 20% of human cancers may promote tumor growth by changing how DNA is organized inside cells. Researchers have [...]
Ebola kills over 5,300 in fastest-growing outbreak on record
Africa’s latest Ebola outbreak has killed nearly 5,400 people, the vast majority of them in the Democratic Republic of Congo (DRC), according to the continent’s top health agency. Africa Centres for Disease Control and [...]
China makes early progress in using sound waves to stimulate damaged brains
Chinese researchers are testing whether focused ultrasound can help restore consciousness in patients with severe brain injuries, adding to a growing international effort to use sound waves to stimulate deep brain structures without surgery. [...]
Micro-drones fly through the body thanks to ultrasound
At the EPFL, micro-drones have been developed that can be moved without a motor or battery.No motors, no batteries, no electronics on board, just small cavities that convert sound waves into thrust: this is [...]
A Single Enzyme Could Hold the Key to Treating a Devastating Brain Disorder
Blocking an enzyme’s production restored brain growth and healthy behaviors in mice engineered to develop Angelman syndrome, pointing to a possible treatment target. Children with Angelman syndrome begin to show difficulties with thinking and [...]
Scientists Develop a Clever New Way To Kill Cancer Cells From the Inside
Scientists have developed an experimental strategy that exploits a chemical byproduct of cancer cells to produce anticancer drugs directly inside them. Scientists in Japan have developed an experimental method that uses a chemical produced [...]
Our books are available worldwide!
Online Sellers other than Amazon, Routledge, and IOPP Indigo Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artifcial Intelligence Global Health Care Equivalency In The Age Of Nanotechnology, Nanomedicine And Artificial [...]
After only a short training, people in a coma managed to send targeted signals
Researchers have succeeded in communicating with brain-injured patients who are unconscious. They see enormous potential in this for future treatments. Patients who lie motionless in bed after a severe brain injury and do not [...]
MIT Scientists Reprogram Immune Cells Inside the Body To Destroy Cancer
Natural killer cells reprogrammed inside mice eliminated lymphoma tumors and helped damaged livers heal, though whether this approach could help people with cancer or autoimmune disease remains unknown. To make a cancer treatment from [...]
Melanoma mRNA Vaccine Shows Promise in Preventing Disease Recurrence
Key takeaways: Phase 3 trial finds personalized intismeran plus pembrolizumab may better prevent high-risk melanoma recurrence after surgery The trial enrolled 1,137 patients and builds on phase 2 results showing about half the recurrence [...]
Scientists Discover a Powerful New Weapon Against a Dangerous Gut Infection
The promise of an experimental treatment for C. difficile gut infections lies partly in the bacteria it leaves alive, according to early laboratory and mouse research. Broad-spectrum antibiotics can disrupt the gut’s microbial community, [...]
Your Bones May Hold a Hidden Clue to Blood Cancer Survival
For people with blood cancers called myelodysplastic syndromes, osteoporosis may hold an overlooked clue to survival, a three-year observational study suggests. In blood cancers that develop in the bone marrow, an important clue to [...]
Researchers Discover What Reading for Pleasure May Be Doing to Your Brain
Reading for pleasure may offer surprising benefits for the brain, with research linking the habit to better mental health, stronger cognitive abilities, and a lower risk of dementia. Reading for pleasure may do far [...]
Scientists Discover a Hidden Trigger That Keeps Inflammation Alive
Inflammation persists after proteins detach from immune receptors, revealing a potential target for autoimmune treatments. Since a Nobel Prize-winning discovery in the 1990s identified molecules called Toll-like Receptors as the guardians of the human [...]
