British recruits will be infected with Covid-lite to test vaccine

Plans are being made for volunteers to be infected with a weakened, computer-designed form of COVID-19 that researchers believe could work as a vaccine.

Plans are being made for volunteers to be infected with a weakened, computer-designed form of COVID-19 that researchers believe could work as a vaccine.

The early-stage trial will take place in a 24-bed quarantine clinic in east London. Codagenix, the American biotech company behind it, is in talks with regulators and expects to begin before the end of the year.

The vaccine consists of an enfeebled version of coronavirus, designed using software and built in a laboratory. The aim is to produce a cheap inoculation administered as a nose drop.

By using a live form of the entire virus, it may be possible to stimulate a broader immune response than other candidate vaccines that expose a person to a small piece of the pathogen.

The use of weakened, or “attenuated”, live viruses as vaccines is well established. The oral polio vaccine, sometimes delivered on a sugar cube, is one example. It was created in the 1950s by researcher Albert Sabin, who infected animals and waited for the polio virus to mutate into a weak form that triggered an immune reaction in humans without causing disease.

Codagenix believes it can achieve a similar result for COVID-19 far more efficiently. Its technique hinges on how our cells read genetic code to build proteins out of amino acids.

Tiny snippets of genetic code, known as codons, tell the cell which amino acids to use. There are 64 types of codon but only 20 types of amino acid. This means that each amino acid can be produced by several types of codon.

However, not all codons are read as efficiently by our cells, even when they produce the same amino acid. The coronavirus replicates itself by hijacking the protein-making machinery of human cells. To do this, it presents our cells with human-friendly codons.

Codagenix has designed a new version of the virus, incorporating hundreds of codons that human cells find much more difficult to read at strategic points.

Robert Coleman, the Codagenix chief executive, said: “We recode a portion of the virus’s genome so that it’s slowly translated by the human host. It’s like giving American high-school students Shakespearean English — they’ll read it, but they’ll have a hard time.”

Laboratory tests suggest the weakened virus replicates at about a thousandth of the rate of the wild strain. It should, however, look identical to the immune system. The hope is that it stimulates the body’s defence mechanisms without causing illness.

It may not work. There have been rare cases where polio has been caused by the live polio virus. However, Codagenix has held early-stage trials in humans of vaccines for influenza using the same technique, without serious side-effects. For its coronavirus project, it is working with the Serum Institute of India, the world’s largest vaccine maker by number of doses produced.

The trials at the quarantine facility in London will be run by hVivo, a company that was founded by academics from Queen Mary University of London.

The Times