Coronavirus vaccine: When might a jab be ready?

Clinical trials are already taking place — but experts emphasise caution

The coronavirus pandemic reached a grim milestone this week, surpassing over a million confirmed cases and reaching a death toll of 50,000 worldwide.

Hopes of a vaccine that could stop the disease have been raised since Covid-19 took hold in China in late December. The UK chief medical adviser, Professor Chris Whitty, has said that a vaccine is £one way out of this ... and we all hope that will happen as quickly as possible."

US scientists say they have developed a potential coronavirus vaccine that produces antibodies capable of fighting the virus and will apply for ‘investigational new drug’ approval from the US Food and Drug Administration.

Researchers at the University of Pittsburgh School of Medicine found the vaccine, tested on mice, produced antibodies in quantities thought to be enough to “neutralise” Covid-19 within two weeks of injection.

The team are far from alone: the World Health Organisation says there are at least 20 coronavirus vaccines are in developmental stages around the world, with the first human trials already beginning in Seattle, led by Boston-based biotech firm Moderna. The trial is backed by the national institutes of health (NIH) and Kaiser Permanente Washington Research Institute.

The speed at which Moderna’s vaccine is entering human trials is unprecedented, largely thanks to Chinese scientists sharing the genetic sequence of Sars-CoV-2 — a move that allowed research groups to grow the live virus and study its behaviour. Researchers were given permission to skip the usual animal testing phase.

In the UK, scientists from Imperial College London said earlier this month they have a “prototype vaccine” with “encouraging” results that could soon be tested on humans.

Dr Robin Shattock, head of mucosal infection and immunity at the university’s department of infectious disease said: “It is a global effort. We are not racing against each other – we are racing against the virus.”

But despite the number of teams working at breakneck speed to develop a vaccine, it could still take around 18 months for any potential vaccine to become available to the general public.

Anthony Fauci, director of the national institute of allergy and infectious diseases in the US and one of Donald Trump’s top health officials, said the process of developing a vaccine “is going to take a year, year-and-a-half at least”.

He dismissed claims by the US president that a vaccine could be produced within “weeks”, saying: “I don’t want to overpromise.”

Before any vaccine can be approved for general use, they must undergo clinical trials which are usually split into three phases. The phases begin with a small pool of healthy volunteers to test the vaccine for safety and monitor it for adverse effects. Next, a larger pool of several hundred people are tested to monitor how effective the vaccine is, and lastly, the same process is repeated in a pool of several thousand people.

Scientists also have to make allowances for variables in the pools of people being tested. Candidates are randomly assigned to either treatment groups or control groups to determine the efficacy of treatments being administered, but some outcomes may prove to be ineffective or unsafe, or both.

Ultimately, scientists must still adhered to the strict protocol involved in developing potential vaccines despite the pressure to move quickly. Any drug can only be made available after a national licensing body or the WHO approves it.

Dr Simon Clarke, professor of cellular microbiology at the University of Reading, told The Independent: “With vaccines you have to generate an immune response that is protective enough – any old immune response won’t do. It has to be able to protect against subsequent infections when that happens.

“Of course [the vaccine] also has to be safe and it has to be long lasting enough. It is pointless giving people immunity for a couple of months.”

He added: “I remind people we’ve been trying to find a vaccine for HIV for the best part of 40 years.”

There is some light at the end of the tunnel. Last week, a veteran coronavirus research team raised hopes when they found that Covid-19 is not mutating at a level that could make it far more dangerous.

Dr Vineet Menachery, a virologist at the University of Texas Medical Branch, told The Independent that the lack of mutation was “good news” because “we could reasonably argue that vaccines would work against most of the strains out there”.

Britain is the largest contributor to an international bid to find a coronavirus vaccine, committing a total of £250m to the Coalition for Epidemic Preparedness Innovations (CEPI).

The funding was announced after Boris Johnson took part in a video conference of the G20 group, where leaders of the world’s largest economies pledged to deliver a “transparent, robust, coordinated, large-scale and science-based global response in the spirit of solidarity”.