Despite its advantages over other vaccine technologies for Covid-19, adenovirus vector vaccines are likely to be tripped up by pre-existing antibodies to the vectors used and the need for a second injection to boost protection.
CanSino Biologics’ Ad5-nCoV and Johnson & Johnson’s AdVac platform-based vaccine use a human adenovirus vector, but a significant chunk of people may already have neutralising antibodies against the vector, decreasing efficacy prospects. Phase I Ad5-nCoV data is also underwhelming, adding credence to the issue of pre-existing antibodies.
AstraZeneca’s AZD1222 and Rome-based ReiThera’s Covid-19 vaccines are also adenovirus vectored but use nonhuman vectors. However, AZD1222’s recent animal data also leave questions about its utility to prevent virus spread. A possible way to improve efficacy is to add a booster shot down the line, perhaps using a different adenovirus vector or even a different vaccine technology. Perhaps AZD1222 only carrying SARS-CoV-2’s spike protein may not be enough.
There are at least 38 companies or universities with a recombinant adenovirus-derived vaccine asset for Covid-19 from preclinical to Phase II/III stages, according to GlobalData. AstraZeneca partnered with Oxford University on 30 April to further develop AZD1222, and on 3 June, the US Federal Government’s vaccine initiative, Operation Warp Speed, named it as one of five finalists along with Johnson & Johnson’s (J&J) candidate. Phase I/II AZD1222 trial (NCT04324606) data are expected shortly, while J&J’s Phase I/IIa will start in July. ReiThera will also begin a clinical investigation in the summer. CanSino is the only company that has released clinical trial data, with Ad5-nCoV already in a Phase II trial (NCT04341389) that has a primary completion date of January 2021.
AZD1222 is concurrently in Phase II/III trial (NCT04400838), with data timelines dependent on community viral transmission rates, the Oxford University website states. A registrational field trial expected to start in the summer is likely to require around 25,000–30,000 volunteers if the annualised incidence rate is 1.5%, this news service reported on 14 May. While a challenge trial design could be considered to quickly gather protection data, such a trial design also has its own operational and ethical issues.
Image Credit: Envato/ Amanda Scott
News This Week
A Promising New Pathway in the Battle Against Aggressive Prostate Cancer
Neuronal Molecule Makes Prostate Cancer More Aggressive Researchers discover a potential therapeutic avenue against an aggressive form of prostate cancer. Prostate cancer is the second most common cancer and the second leading cause of [...]
Nasal Vaccines: Stopping the COVID-19 Virus Before It Reaches the Lungs
The Pfizer-BioNTech and Moderna mRNA vaccines have played a large role in preventing deaths and severe infections from COVID-19. But researchers are still in the process of developing alternative approaches to vaccines to improve [...]
NASA Tracking a Huge, Growing Anomaly in Earth’s Magnetic Field – with video
NASA is actively monitoring a strange anomaly in Earth's magnetic field: a giant region of lower magnetic intensity in the skies above the planet, stretching out between South America and southwest Africa. This vast, developing [...]
New, Better Models Show How Infectious Diseases Like COVID-19 Spread
Infectious diseases such as COVID-19 can spread rapidly across the globe. Models that can predict how such diseases spread will strengthen national surveillance systems and improve public health decision-making. The COVID-19 pandemic has emphasized the [...]
Human Antibodies Discovered That Can Block Multiple Coronaviruses Including COVID-19
Results from a Scripps Research and UNC team pave the way for a vaccine and therapeutic antibodies that could be stockpiled to fight future coronavirus pandemics. A team of scientists from Scripps Research and [...]
Nanotechnology could be used to treat lymphedema
The human body is made up of thousands of tiny lymphatic vessels that ferry white blood cells and proteins around the body, like a superhighway of the immune system. It's remarkably efficient, but if [...]
DNA Nanotechnology Tools – From Design to Applications
Suite of DNA nanotechnology devices engineered to overcome specific bottlenecks in the development of new therapies, diagnostics, and understanding of molecular structures. DNA nanostructures with their potential for cell and tissue permeability, biocompatibility, and [...]
Regenerating bone with deer antler stem cells
Scientists from a collection of Chinese research institutions collaborated on a study of organ regeneration in mammals, finding deer antler blastema progenitor cells are a possible source of conserved regeneration cells in higher vertebrates. [...]
AI Takes On Cancer: Analysis of Mutations Could Lead to Improved Therapy
Cancer is a complex and diverse disease, and its range of associated mutations is vast. The combination of these genomic changes in an individual is referred to as their “mutational landscape.” These landscapes vary [...]
Exposing tumours to bacteria converts immune cells to cancer killers
New research on inflammation could lead to better treatments to improve outcomes for people with advanced or previously untreatable cancers. Introducing bacteria to a tumour’s microenvironment creates a state of acute inflammation that triggers [...]
Smart nanotechnology for more accurate delivery of insulin
More efficient and longer lasting glucose-responsive insulin that eliminates the need for people with type 1 diabetes to measure their glucose levels could be a step closer thanks to a Monash University-led project. Published [...]
Efficiently Harvesting Rare Earth Elements From Wastewater Using Exotic Bacteria
The novel strains of cyanobacteria exhibit a fast and efficient “biosorption” of rare earth elements, making recycling possible. Rare earth elements (REEs) are a set of 17 metallic elements that possess similar chemical properties. [...]
Resisting Treatment: Cancer Cells Shrink or Super-Size To Survive
A new approach to image analysis has uncovered how cancer cells manipulate their size as a means of resisting treatment. Researchers have discovered that cancer cells are capable of either shrinking or super-size themselves [...]
New Research Explains Why Children Avoid Severe COVID-19 Symptoms
According to new research, children exhibit a robust initial immune response to the coronavirus, however, they are unable to transfer this response to long-lasting memory T cells like adults do. Researchers led by scientists [...]
Scientists Unravel Protein Map of Mitochondria
A new study sheds light on the organization of proteins within mitochondria. Mitochondria, the “powerhouses” of cells, play a crucial role in the energy production of organisms and are involved in various metabolic and [...]
Mystifying Trapping Phenomenon: A Surprising Way To Catch a Microparticle
New insights could advance microfluidics and drug delivery systems. New study finds obstacles can trap rolling microparticles in fluid Through simulations and experiments, physicists attribute the trapping effect to stagnant pockets of fluid, created [...]