Thursday, September 09, 2021

Co-inventor of mRNA shots sets sights on pan-coronavirus vaccine


Issued on: 09/09/2021 -


The University of Pennsylvania immunologist, who on Thursday shared the $3 million 2022 Breakthrough Prize in Life Sciences with his long time collaborator Katalin Kariko, is now spearheading efforts to design a new vaccine against all coronaviruses 
Sharon L. Taffet Pennsylvania School of Medicine/AFP


Washington (AFP)

Drew Weissman's decades of research helped pave the way for mRNA Covid-19 vaccines, but the scientist isn't resting on his laurels.

The University of Pennsylvania immunologist, who on Thursday shared the $3 million 2022 Breakthrough Prize in Life Sciences with his longtime collaborator Katalin Kariko, is now spearheading efforts to design a new vaccine against all coronaviruses.

The Silicon Valley-backed award honors major discoveries with the highest cash amounts in science.

"There have been three (coronavirus) pandemics or epidemics in the past 20 years," Weissman told AFP in an interview, referring to the original SARS virus, MERS and Covid-19.

"You have to assume there's going to be more, and our idea was that we could wait for the next coronavirus epidemic or pandemic, and then spend a year and a half making a vaccine. Or we could make one now and have it either ready to go, or use it now."

The 62-year-old and his team started work on the project last spring and have so far published two papers, with promising results.

One of the vaccines was shown to prevent SARS and a few other animal coronaviruses that have the potential to cross into humans.

By now, many are familiar with the basic principles of mRNA (messenger ribonucleic acid) vaccines: they deliver genetic instructions to our cells to build the spike protein of the coronavirus, in order to evoke antibodies when our bodies encounter the real virus.

The new focus is to try to train our immune systems to parts of the virus that do not mutate as fast as the spike. These are called "conserved regions."

As a practicing doctor for most of his life, "my dream since starting college and medical school was to make something that helps people," Weissman said, adding it made him "incredibly happy" to see the vaccines he laid the groundwork for save lives.

But while he foresaw the issue of global vaccine inequality -- and is working on a project with the Thai government to develop their own Covid-19 vaccine for this reason -- he admitted to being astonished by the level of vaccine hesitancy seen in wealthy countries.

"The conservative anti-science, anti-government people completely surprised us. I just didn't expect that group to come out against vaccines," he said.

- New applications -


While mRNA technology is enjoying huge attention, Weissman remembers a time when the field was a scientific backwater.

"We started working together in 1998, and that was without much funding and without much in the way of publications," he said of his work with Kariko.

In 2005, they found a way to alter synthetic RNA to stop it from causing a massive inflammatory response found in animal experiments.

"Just before our paper was published I said 'Our phones are going to ring off the hook,'" he recalls.

"We sat there staring at our phones for five years, and they never rang!"

With a second big breakthrough in 2015, they found a new way to deliver the particles safely and effectively to their target cells, using a fatty coating called "lipid nanoparticles."

Both developments are part of the Pfizer and Moderna Covid-19 vaccines today.

Beyond vaccines, mRNA technology is also being heralded for its potential to revolutionize medicine.

Weissman's team is working on using RNA to develop a single-injection gene therapy to overcome the defect that causes sickle cell anemia, a genetic blood disease that 200,000 babies are born with in Africa every year.

Significant technical challenges remain to ensure the treatment is able to correctly edit genes and is safe, but the researchers are hopeful.

Bone marrow transplant, an expensive treatment with serious risks, is currently the only cure.



French scientist recognized for rapid DNA sequencing technique key in Covid fight




Issued on: 09/09/2021 
Image non datée d'observations au microscope du SARS-CoV-2, le virus causant le Covid-19, transmise par les Instituts nationaux de santé (NIH) américains 
Handout National Institute of Allergy and Infectious Diseases/AFP


Washington (AFP)

Twenty-five years ago, French biophysicist Pascal Mayer had an idea that seemed nothing short of "crazy." Today, his research has paved the way for a rapid and inexpensive DNA sequencing technique used around the world in the battle against Covid-19.

On Thursday, Mayer, 58, who hails from the town of Riom in central France, was awarded the prestigious Breakthrough Prize in life sciences, alongside British researchers Shankar Balasubramanian and David Klenerman.

The American prize, launched by Silicon Valley entrepreneurs to recognize the latest scientific advances, carries an award of a hefty $3 million, compared to $1 million given to Nobel Prize laureates. Mayer and his colleagues will get $1 million each.

Thanks to the new method, known as next generation sequencing (NGS), scientists can analyze coronavirus mutations day by day to identify and monitor new variants.

Without this technique, studying the rapidly spreading new Covid-19 mutations would be much more costly and, more importantly, take much longer, Mayer told AFP.

But back in 1996, when Mayer began developing the idea, it sounded wild.

"It seemed crazy, so I looked pretty crazy when I talked about it," said Mayer, who now works at his own bioresearch company.

- DNA colonies -


A genome is a complete set of an organism's genes: its hereditary information.

Each gene represents a small piece of DNA, which in turn, consists of four letters: A (for adenine), T (thymine), C (cytosine) and G (guanine).

Made up of 23 chromosomes, the human genome contains more than three billion letters.

"It's a bit like having an encyclopedia consisting of 23 volumes," Mayer explained.

To sequence the genome is to "read" the order of these letters.

The sequencing of the first complete human genome was completed in 2003, after ten years and an investment of over $1 billion. The technique that was used then is called Sanger sequencing.

Thanks to NGS, also called massive parallel sequencing, the process can now be done overnight at a cost of $1,000.

How is that achieved? Instead of reading the pages of each book one by one, they are all read simultaneously.

"It's like putting all the pages on a soccer field, and being able to take a photo of the field at once," explained Mayer.

One of the keys to his technique is creating clusters of DNA, by cutting up the genome into small pieces, then creating thousands of copies of them and grouping them into islands of sorts.

Assembled together, they can be read simultaneously and more easily by fluorescence.

Mayer said the simplicity of the technique is its key strength and a source of pride for him.

The sequencing takes place "with a stroke of the pipette," he said.

- 17,000 machines -

After studying at the University of Strasbourg and completing postdoctoral fellowships in Canada and in France, Mayer tested his idea for the first time in Geneva, in the research center of a pharmaceutical company where he then worked.

Two key patents were filed in April 1997.

The technology was later acquired by a start-up founded by Balasubramanian and Klenerman, two British scientists working on the same problem.

Their company was eventually bought by the US genetic research company Illumina, the global leader in genetic sequencing, which has 17,000 sequencing machines around the globe.

Besides Covid-19 research, massive parallel sequencing is widely used to diagnose and treat certain cancers and rare diseases.

It is also used in forensic investigations to analyze DNA samples from crime scenes.

Mayer does not own the property rights to the sequencing method, so he doesn't share in the profits.

But he hopes the award will give a boost to his bioresearch company Alphanosos, which he founded in 2014.

Mayer intends to invest a part of his award to fund projects at his company, including treatment for coronavirus.

© 2021 AFP

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