Human trials have begun of a new mutant-beating COVID-19 vaccine that can be swallowed as a pill, given under the tongue or injected.
It’s part of a ‘second generation’ of vaccine science that’s been developed around the world, in a bid to make suppressing this life-stopping virus easier.
The hAd5 T-cell vaccine is being trialled in the US and South Africa with the goal of “creating longer-term protection from the virus.”
According to a statement from US company ImmunityBio, the new vaccine targets the mutation-prone outer spike protein (S) – as do all COVID-19 vaccines being deployed.
But it also targets the more stable inner nucleocapsid (N) protein, activating antibodies, memory B cells, and T-cells against the coronavirus (SARS-CoV-2).
This N protein is less prone to mutation than the spike protein – and may be the key to subduing the variants of the coronavirus that are compromising vaccine efficacy.
The new vaccine, in pill form, may serve as a “booster” for all existing vaccines.
So far the vaccine has been trialled successfully in monkeys, including the pill version. The Phase I trial will investigate the vaccine’s safety in humans.
A ‘universal’ fix?
ImmunityBio, a late-stage immunotherapy company, is talking a big game.
A year ago the company talked about developing a vaccine pill that would be delivered in the mail.
It says the new vaccine has “the potential to serve as a universal T-cell boost to current vaccines or address mutations where other vaccines might fail” – including the tricky South African variant.
This strain has been found to reduce the effectiveness of all available vaccines against moderate illness, and to a significantly greater extent in the AstraZeneca vaccine.
While the South African variant has been touted as a deadly variant, vaccines, including that from AstraZeneca, have continued to prove effective against serious illness.
On Thursday, Moderna announced it was beginning clinical trials of a new version of its COVID-19 vaccine, a variant-specific booster shot designed to subdue the South African strain.
All vaccine makers are working to beat these variants, and a universal mutant-killing jab would certainly be welcome.
This week, the Oxford team that developed the AstraZeneca vaccine said it was investigating the viability of creating tablets and nasal sprays as alternative to injections.
These would be part of the second-generation vaccines that makers are developing to meet the evolving challenge of variants, and to further boost efficacy.
A reality check
Dr Patrick Soon-Shiong is chairman and CEO of ImmunityBio, based in California.
In a prepared statement he said: “We are excited about the potential of our COVID-19 vaccine candidate and the issues it could solve globally. Unlike antibody-based vaccines, T-cell-based vaccines kill the infected cell, preventing virus replication, and could provide long-term immune memory to recipients.”
He noted that pursuing a vaccine that does not rely solely on targeting the S protein where the mutations are occurring “is of critical importance as multiple variants of the SARS-CoV-2 virus have appeared globally, with concentrated outbreaks beginning in South Africa”.
Dr Soon-Shiong said the new virus had provided “complete protection to a viral challenge in our non-human primate data”.
He said the T-cell vaccine approach to neutralising mutational changes could prove effective in treating other infectious diseases, including influenza.
The approach could well enough to end “the need for annual injections”.
All of this sounds terrific. The innovations are impressive, at least in concept. And the promise of a universal vaccine is tantalising. Indeed, universal vaccines against seasonal flu are something of a holy grail, as yet unrealised.
Finally, success with monkeys is encouraging, but it doesn’t translate to immediate success in humans.
After Phase I establishes the safety of the new vaccine, there are Phases II and III – to see if it actually works on people – to get through.
These won’t be completed until the end of the year, at the earliest.