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
Study Shows Brain Signals Only Matter if They Arrive on Time
Signals are processed only if they reach the brain during brief receptive cycles. This timing mechanism explains how attention filters information and may inform therapies and brain-inspired technologies. It has long been recognized that [...]
Does Space-Time Really Exist?
Is time something that flows — or just an illusion? Exploring space-time as either a fixed “block universe” or a dynamic fabric reveals deeper mysteries about existence, change, and the very nature of reality. [...]
Unlocking hidden soil microbes for new antibiotics
Most bacteria cannot be cultured in the lab-and that's been bad news for medicine. Many of our frontline antibiotics originated from microbes, yet as antibiotic resistance spreads and drug pipelines run dry, the soil [...]
By working together, cells can extend their senses beyond their direct environment
The story of the princess and the pea evokes an image of a highly sensitive young royal woman so refined, she can sense a pea under a stack of mattresses. When it comes to [...]
Overworked Brain Cells May Hold the Key to Parkinson’s
Scientists at Gladstone Institutes uncovered a surprising reason why dopamine-producing neurons, crucial for smooth body movements, die in Parkinson’s disease. In mice, when these neurons were kept overactive for weeks, they began to falter, [...]
Old tires find new life: Rubber particles strengthen superhydrophobic coatings against corrosion
Development of highly robust superhydrophobic anti-corrosion coating using recycled tire rubber particles. Superhydrophobic materials offer a strategy for developing marine anti-corrosion materials due to their low solid-liquid contact area and low surface energy. However, [...]
This implant could soon allow you to read minds
Mind reading: Long a science fiction fantasy, today an increasingly concrete scientific goal. Researchers at Stanford University have succeeded in decoding internal language in real time thanks to a brain implant and artificial intelligence. [...]
A New Weapon Against Cancer: Cold Plasma Destroys Hidden Tumor Cells
Cold plasma penetrates deep into tumors and attacks cancer cells. Short-lived molecules were identified as key drivers. Scientists at the Leibniz Institute for Plasma Science and Technology (INP), working with colleagues from Greifswald University Hospital and [...]
This Common Sleep Aid May Also Protect Your Brain From Alzheimer’s
Lemborexant and similar sleep medications show potential for treating tau-related disorders, including Alzheimer’s disease. New research from Washington University School of Medicine in St. Louis shows that a commonly used sleep medication can restore normal sleep patterns and [...]
Sugar-Coated Nanoparticles Boost Cancer Drug Efficacy
A team of researchers at the University of Mississippi has discovered that coating cancer treatment carrying nanoparticles in a sugar-like material increases their treatment efficacy. They reported their findings in Advanced Healthcare Materials. Over a tenth of breast [...]
Nanoparticle-Based Vaccine Shows Promise in Fighting Cancer
In a study published in OncoImmunology, researchers from the German Cancer Research Center and Heidelberg University have created a therapeutic vaccine that mobilizes the immune system to target cancer cells. The researchers demonstrated that virus peptides combined [...]
Quantitative imaging method reveals how cells rapidly sort and transport lipids
Lipids are difficult to detect with light microscopy. Using a new chemical labeling strategy, a Dresden-based team led by André Nadler at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) and [...]
Ancient DNA reveals cause of world’s first recorded pandemic
Scientists have confirmed that the Justinian Plague, the world’s first recorded pandemic, was caused by Yersinia pestis, the same bacterium behind the Black Death. Dating back some 1,500 years and long described in historical texts but [...]
“AI Is Not Intelligent at All” – Expert Warns of Worldwide Threat to Human Dignity
Opaque AI systems risk undermining human rights and dignity. Global cooperation is needed to ensure protection. The rise of artificial intelligence (AI) has changed how people interact, but it also poses a global risk to human [...]
Nanomotors: Where Are They Now?
First introduced in 2004, nanomotors have steadily advanced from a scientific curiosity to a practical technology with wide-ranging applications. This article explores the key developments, recent innovations, and major uses of nanomotors today. A [...]
Study Finds 95% of Tested Beers Contain Toxic “Forever Chemicals”
Researchers found PFAS in 95% of tested beers, with the highest levels linked to contaminated local water sources. Per- and polyfluoroalkyl substances (PFAS), better known as forever chemicals, are gaining notoriety for their ability [...]