Researchers in the United States have conducted a study showing that the coronavirus disease 2019 (COVID-19) vaccines developed by Pfizer-BioNTech and Moderna generate a coordinated adaptive immune response that is capable of eliciting recall responses to future infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
The team from the University of California found that immunization with either Pfizer-BioNTech’s BNT162b2 or Moderna’s mRNA-1273 vaccine-induced enrichment of spike-specific B cells.
The viral spike protein mediates the initial stage of the SARS-CoV-2 infection process and is the primary target of antibodies following natural infection or vaccination.
Ilhem Messaoudi and colleagues say that vaccination also activated CD4 T cells and induced robust antigen-specific polyfunctional CD4 T cell responses.
Furthermore, clonally expanded CD8 T cells were observed in all vaccine recipients.
A pre-print version of the research paper is available on the bioRxiv* server, while the article undergoes peer review.
Vaccination and infection provide two different pathways to immunity
Since the COVID-19 outbreak first began in December 2019 in Wuhan, China, intense global efforts to rapidly develop effective vaccines against the causative agent SARS-CoV-2 have led to the emergency use authorization of several vaccines.
These include the messenger RNA- (mRNA) based vaccines developed by Pfizer (BNT162b2) and Moderna (mRNA-1273). Findings from clinical trials indicated that a 95% maximal protection is achieved within 1 to 2 months following the second dose of either vaccine, including protection against several circulating SARS-CoV-2 variants of concern.
However, the mechanisms by which these vaccines elicit long-lasting cellular immune responses to the virus remain poorly understood.
Natural infection and vaccination provide two different pathways to immunity, which studies have previously shown to be characterized by distinct T and B cell responses.
“Additional studies that integrate functional, transcriptional, and repertoire analysis of the memory immune cell response to COVID-19 mRNA vaccination are needed,” writes Messaoudi and colleagues.
What did the researchers do?
The team used single-cell RNA sequencing and functional assays to assess humoral (antibody) and cellular responses to two doses of either the Pfizer-BioNTech or Moderna mRNA vaccine (14 days following a second dose) in four individuals. The results were compared with the immune responses observed in three convalescent individuals who had experienced asymptomatic or mild infection.
What did the study find?
Both infection and vaccination induced anti-SARS-CoV-2 binding and neutralizing antibodies.
These antibodies were detected as early as two weeks following a first vaccine dose, with levels increasing several-fold after a second dose.
While neutralizing antibody titers following the first vaccine dose were comparable to those among convalescent individuals, significantly higher levels were observed in the vaccinees following the booster dose.
However, several important B cell adaptations were shared between vaccinees and convalescent individuals.
Analysis by flow cytometry revealed a reduction in the level of naïve B cells, but an expansion of memory B cells in both groups.
Additionally, single-cell RNA sequencing showed a reduction in IgA+ memory B cells following vaccination, a finding that has recently been described for convalescent individuals.
News
Vision can be rebooted in adults with amblyopia, study suggests
Temporarily anesthetizing the retina briefly reverts the activity of the visual system to that observed in early development and enables growth of responses to the amblyopic eye, new research shows. In the common vision [...]
Ultrasound-activated Nanoparticles Kill Liver Cancer and Activate Immune System
A new ultrasound-guided nanotherapy wipes out liver tumors while training the immune system to keep them from coming back. The study, published in Nano Today, introduces a biodegradable nanoparticle system that combines sonodynamic therapy and cell [...]
Magnetic nanoparticles that successfully navigate complex blood vessels may be ready for clinical trials
Every year, 12 million people worldwide suffer a stroke; many die or are permanently impaired. Currently, drugs are administered to dissolve the thrombus that blocks the blood vessel. These drugs spread throughout the entire [...]
Reviving Exhausted T Cells Sparks Powerful Cancer Tumor Elimination
Scientists have discovered how tumors secretly drain the energy from T cells—the immune system’s main cancer fighters—and how blocking that process can bring them back to life. The team found that cancer cells use [...]
Very low LDL-cholesterol correlates to fewer heart problems after stroke
Brigham and Women's Hospital's TIMI Study Group reports that in patients with prior ischemic stroke, very low achieved LDL-cholesterol correlated with fewer major adverse cardiovascular events and fewer recurrent strokes, without an apparent increase [...]
“Great Unified Microscope” Reveals Hidden Micro and Nano Worlds Inside Living Cells
University of Tokyo researchers have created a powerful new microscope that captures both forward- and back-scattered light at once, letting scientists see everything from large cell structures to tiny nanoscale particles in a single shot. Researchers [...]
Breakthrough Alzheimer’s Drug Has a Hidden Problem
Researchers in Japan found that although the Alzheimer’s drug lecanemab successfully removes amyloid plaques from the brain, it does not restore the brain’s waste-clearing system within the first few months of treatment. The study suggests that [...]
Concerning New Research Reveals Colon Cancer Is Skyrocketing in Adults Under 50
Colorectal cancer is striking younger adults at alarming rates, driven by lifestyle and genetic factors. Colorectal cancer (CRC) develops when abnormal cells grow uncontrollably in the colon or rectum, forming tumors that can eventually [...]
Scientists Discover a Natural, Non-Addictive Way To Block Pain That Could Replace Opioids
Scientists have discovered that the body can naturally dull pain through its own localized “benzodiazepine-like” peptides. A groundbreaking study led by a University of Leeds scientist has unveiled new insights into how the body manages pain, [...]
GLP-1 Drugs Like Ozempic Work, but New Research Reveals a Major Catch
Three new Cochrane reviews find evidence that GLP-1 drugs lead to clinically meaningful weight loss, though industry-funded studies raise concerns. Three new reviews from Cochrane have found that GLP-1 medications can lead to significant [...]
How a Palm-Sized Laser Could Change Medicine and Manufacturing
Researchers have developed an innovative and versatile system designed for a new generation of short-pulse lasers. Lasers that produce extremely short bursts of light are known for their remarkable precision, making them indispensable tools [...]
New nanoparticles stimulate the immune system to attack ovarian tumors
Cancer immunotherapy, which uses drugs that stimulate the body’s immune cells to attack tumors, is a promising approach to treating many types of cancer. However, it doesn’t work well for some tumors, including ovarian [...]
New Drug Kills Cancer 20,000x More Effectively With No Detectable Side Effects
By restructuring a common chemotherapy drug, scientists increased its potency by 20,000 times. In a significant step forward for cancer therapy, researchers at Northwestern University have redesigned the molecular structure of a well-known chemotherapy drug, greatly [...]
Lipid nanoparticles discovered that can deliver mRNA directly into heart muscle cells
Cardiovascular disease continues to be the leading cause of death worldwide. But advances in heart-failure therapeutics have stalled, largely due to the difficulty of delivering treatments at the cellular level. Now, a UC Berkeley-led [...]
The basic mechanisms of visual attention emerged over 500 million years ago, study suggests
The brain does not need its sophisticated cortex to interpret the visual world. A new study published in PLOS Biology demonstrates that a much older structure, the superior colliculus, contains the necessary circuitry to perform the [...]
AI Is Overheating. This New Technology Could Be the Fix
Engineers have developed a passive evaporative cooling membrane that dramatically improves heat removal for electronics and data centers Engineers at the University of California San Diego have created an innovative cooling system designed to greatly enhance [...]
