Saturday, April 4, 2020

Coronavirus cure: COVID-19 vaccine prospect shows 'promise' in studies.



CORONAVIRUS researchers believe they have discovered a potential vaccine for the COVID-19 pandemic.
University of Pittsburgh School of Medicine scientists this Thursday announced a potential vaccine against the new coronavirus causing the COVID-19 pandemic. When tested in mice, the vaccine produces antibodies specific to COVID-19 at quantities considered sufficient for killing the deadly virus.

Published by The Lancet, the paper is the first study to be published after critique from fellow scientists at outside institutions that describes a candidate vaccine for COVID-19.

The researchers were able to act quickly due to experience with working during earlier coronavirus epidemics.

Andrea Gambotto, associate professor of surgery at the Pitt School of Medicine and co-senior author, said: "We had previous experience on SARS-CoV in 2003 and MERS-CoV in 2014.

"These two viruses, which are closely related to SARS-CoV-2, teach us that a particular protein, called a spike protein, is important for inducing immunity against the virus.

"We knew exactly where to fight this new virus.
"That's why it's important to fund vaccine research. You never know where the next pandemic will come from."


Louis Falo, professor and chair of dermatology at Pitt's School of Medicine and co-senior author, added: "Our ability to rapidly develop this vaccine was a result of scientists with expertise in diverse areas of research working together with a common goal."

The vaccine described in this paper has been dubbed by the authors as PittCoVacc, short for Pittsburgh Coronavirus Vaccine

Compared to the experimental mRNA vaccine candidate that just entered clinical trials, PittCoVacc follows a more established approach.

The researchers created PittCoVacc using lab-made pieces of a viral protein to build immunity, in a similar way to how the current flu shots work.

The team incorporated a novel approach to deliver the drug, called a microneedle array, to increase potency.

This is a fingertip-sized patch of 400 tiny needles that deliver the spike protein pieces into the skin, where the immune reaction is strongest.

The patch is applied like a plaster and then the needles — made entirely of sugar and the protein pieces — simply dissolve into the skin.

Professor Falo said: "We developed this to build on the original scratch method used to deliver the smallpox vaccine to the skin, but as a high-tech version that is more efficient and reproducible patient to patient.

"And it's actually pretty painless — it feels kind of like Velcro."

The system also is highly scalable, as the protein pieces are manufactured by what has been described as a "cell factory".

This sees layers upon layers of cultured cells engineered to express the SARS-CoV-2 spike protein and these can be stacked further to multiply yield.

And purifying the protein also can be done at industrial scale.

Mass-producing the microneedle array involves spinning down the protein-sugar mixture into a mould using a centrifuge.

Once manufactured, the vaccine can sit at room temperature until it's needed, eliminating the need for refrigeration during transport or storage.

Dr Gambotto added: "For most vaccines, you don't need to address scalability to begin with.

"But when you try to develop a vaccine quickly against a pandemic that's the first requirement."