Powerful inhalable Covid-19 vaccine passes preliminary tests

A while ago I reported on the emergence of a new way to immunise people against disease – contagious vaccines. And, now as the Cornonavirus pandemic, Covid-19, rages around the world and researchers everywhere turn to AI’s, powerful gene editing tools, and supercomputers to help them develop vaccines faster than ever before, when it comes to getting everyone immunised against Covid-19 there’s still one big stumbling block to overcome, I am, of course, talking about the amount of time that it will take companies to manufacture the billions of doses they need to vaccinate the world.

Now though researchers at the University of California San Fransciso have announced they’ve developed a new type of Covid vaccine that could persist in aerosol form, so while it’s not contagious, it’s yet another interesting twist in the story of creating next gen vaccines and treatments – treatments such as the one I discussed a while ago that could let doctors cure Cystic Fibrosis using nothing more than an mRNA based ainhaler that edits patients genomes when inhaled in order to cure them which is as amazing as it is freaky! It also means that in the future these treatments could be administered en masse via a building or venue's air conditioning, and via other means...

Can this aerosol based vaccine help fight Covid?

Infections from SARS-CoV-2 are still rising worldwide, passing 22 million cases and nearly 800,000 deaths at the time of writing, with unimaginable destructive power, creating serious economic strife, a seemingly-endless loss of life, and growing health costs.

However, in a recent experiment researchers used a set of synthetic nanobodies to successfully disrupt the virus’s binding process, effectively neutralising it, according to a recent study shared on a pre-print blog. What's more, some of the nanobodies are robust enough for aerosol-based applications, which in short means you could put this vaccine in an aerosol can or even spray it through a ventilation system to immunise people against the deadly virus. You could say we've found a way to muzzle the novel coronavirus.

The new prototype inhalable vaccine

Covid infects human cells via an interaction between a Spike protein and the human host cell receptor called angiotensin-converting enzyme 2 (ACE2). The virus then makes its way into the human host cells using its Spike protein and a host cell receptor, but the new synthetic nanobodies disrupt that interaction, according to the study.

“Though they function much like the antibodies found in the human immune system, nanobodies offer a number of unique advantages for effective therapeutics against SARS-CoV-2,” explained co-inventor Aashish Manglik, MD, PhD, an assistant professor of pharmaceutical chemistry who frequently employs nanobodies as a tool in his research on the structure and function of proteins that send and receive signals across the cell’s membrane.

For example, nanobodies are an order of magnitude smaller than human antibodies, which makes them easier to manipulate and modify in the lab. Their small size and relatively simple structure also makes them significantly more stable than the antibodies of other mammals. Plus, unlike human antibodies, nanobodies can be easily and inexpensively mass-produced: scientists insert the genes that contain the molecular blueprints to build nanobodies into E. coli or yeast, and transform these microbes into high-output nanobody factories. The same method has been used safely for decades to mass-produce insulin.

During their experiments the team screened a yeast surfaced-displayed library of synthetic nanobody sequences and found a group of nanobodies capable of binding to several the epitopes on the Spike and block ACE2 interactions.

The first, called Cryogenic Electron Microscopy (cryo-EM) showed an exceptionally stable nanobody - Nb6. This binds the coronavirus Spike protein into a fully-inactive conformation with each Receptor Binding Domain (RBD) locked into its inaccessible down-state.

With the Spike protein in a down-state, which is like a key too short to extend into a locking mechanism, this made the coronavirus unable to bind with ACE2 in human cells.

Meanwhile a second mechanism created a trivalent nanobody called mNb6-tri which remained stable and functional despite heat treatment, lyophilization, and aerosolization, and it’s this second treatment that, in this case, is so unique.

Hopefully though, and getting back to brass tacks, all this research and these breakthroughs will move us closer to getting out from under the pandemics cloud and helping life return to normal – albeit the new normal. So stay tuned and until next time, stay safe.

Source: UCSF