What happens if you mix COVID-19 vaccines, receiving a first dose of one jab and a second dose of a different inoculation? Scientists want to know.
Why? Because mixing doses might give governments more flexibility to stretch available vaccine supplies across populations, ensuring more people get vaccinated and doses won’t go to waste. There’s also speculation that, at least for some of the vaccines, receiving a second dose of a different vaccine might produce a stronger immune response.
Finally, if COVID-19 becomes endemic —as many experts think is likely— and people need frequent booster shots to retain immunity, then it is possible people will need to receive boosters of a different shot than they received initially.
The U.K. government is sponsoring one of the earliest and largest clinical trials of this kind of mixing, which experts call “heterologous dosing.” And the very first preliminary results from that study are in: People who received the Pfizer vaccine followed by the AstraZeneca jab or vice versa, were more likely to experience uncomfortable reactions to the second dose than people who received two doses of the same vaccine, researchers at the University of Oxford reported in a research note published in the peer-reviewed medical journal The Lancet.
These reactions included flu-like symptoms, such as fever, muscle aches, lethargy, and a general feeling of being unwell. The scientists said that none of these side effects were severe, describing them as “mild to moderate.” They also said the symptoms were short-lived, lasting at most a few days and that there had been no other safety concerns so far with mixing the Pfizer and AstraZeneca vaccines.
More frequent and pronounced reactions could lead to higher rates of absenteeism from work on the day after the second inoculation. This could be an important consideration, especially when governments were vaccinating healthcare workers, according to Matthew Snape, a University of Oxford professor of paediatrics and vaccinology who is leading the mixed dose clinical trial. The scientists also cautioned that the study only included people over the age of 50 and that it is possible that younger people might react differently….
News
Novel mRNA therapy curbs antibiotic-resistant infections in preclinical lung models
Researchers at the Icahn School of Medicine at Mount Sinai and collaborators have reported early success with a novel mRNA-based therapy designed to combat antibiotic-resistant bacteria. The findings, published in Nature Biotechnology, show that in [...]
New skin-permeable polymer delivers insulin without needles
A breakthrough zwitterionic polymer slips through the skin’s toughest barriers, carrying insulin deep into tissue and normalizing blood sugar, offering patients a painless alternative to daily injections. A recent study published in the journal Nature examines [...]
Multifunctional Nanogels: A Breakthrough in Antibacterial Strategies
Antibiotic resistance is a growing concern - from human health to crop survival. A new study successfully uses nanogels to target and almost entirely inhibit the bacteria P. Aeruginosa. Recently published in Angewandte Chemie, the study [...]
Nanoflowers rejuvenate old and damaged human cells by replacing their mitochondria
Biomedical researchers at Texas A&M University may have discovered a way to stop or even reverse the decline of cellular energy production—a finding that could have revolutionary effects across medicine. Dr. Akhilesh K. Gaharwar [...]
The Stunning New Push to Protect the Invisible 99% of Life
Scientists worldwide have joined forces to build the first-ever roadmap for conserving Earth’s vast invisible majority—microbes. Their new IUCN Specialist Group reframes conservation by elevating microbial life to the same urgency as plants and [...]
Scientists Find a Way to Help the Brain Clear Alzheimer’s Plaques Naturally
Scientists have discovered that the brain may have a built-in way to fight Alzheimer’s. By activating a protein called Sox9, researchers were able to switch on star-shaped brain cells known as astrocytes and turn them into [...]
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 [...]















