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Infectious Diseases

Updated 01 May 2020

Fourth vaccine candidate enters clinical trial

A fourth vaccine has just joined the leaderboard in the race to a safe, efficient vaccine against the new coronavirus. Here’s what we know.

With the infection rate of the new coronavirus now at close to 2.7 million worldwide and lockdown and physical distancing measures being implemented in many parts of the world, researchers are racing to find a successful vaccine.

Now, according to a report, Germany has authorised their first clinical trial of a vaccine – the fourth globally to enter the clinical trial phase.

Who is developing this vaccine?

The vaccine is being developed by cancer researcher and immunologist Ugur Sahin and his team at the pharmaceutical company BioNTech, in partnership with pharmaceutical giant Pfizer. 

How does it work?

The vaccines currently in development are all developed in a different way, as explained in a previous Health24 article.

This vaccine, referred to as BNT162b1 by the developers, is a so-called RNA vaccine, which means that it contains an mRNA strand that is the code for a disease-specific antigen. In this case, the developers used the genetic information (the mRNA) of the new coronavirus, which is transferred into human cells through lipid nanoparticles.

The cell transforms this genetic information into a protein, which is then expected to stimulate an immune reaction to help fight the new coronavirus.

What does the trial entail?

The trial, which is the fourth clinical trial for the new coronavirus, will be conducted in 200 healthy people, according to the Paul Erlich Institute (PEI), Germany’s regulator for vaccines. After that, the second stage will include more people, some who are at higher risk of the new coronavirus.

"Trials of vaccine candidates in humans are an important milestone on the road to safe and efficacious vaccines against Covid-19 for the population in Germany and internationally," said Klaus Cichutek, head of the PEI in a statement.

Is this the only vaccine being developed by the company?

While BNT162b1 has been given the go-ahead for clinical trials, BioNTech, in collaboration with pharmaceutical company Pfizer, is developing three other RNA vaccines.

Where are we on the road to a vaccine?

Currently, a blueprint from the World Health Organization (WHO) sums up 70 vaccine candidates, of which three were already entering clinical trials. This vaccine will now join the top three.

So far, the top three are an RNA vaccine, an adenovirus vaccine and a DNA plasmid vaccine.

Why is it so difficult to develop a vaccine?

As with any drug in development, it has to be subjected to vital in vitro and animal tests before entering clinical trials. As there is currently no targeted drug against Covid-19, scientists are fast-forwarding the process as much as they can.

Clinical trials are conducted in four phases:

Phase 1 trials test whether the vaccine is safe, and usually last about six months.

Phase 2 trials examine how well the vaccine works in creating an immune response in volunteers, and last up to a year.

Phase 3 and 4 trials track the effectiveness of the vaccine in preventing infection in people exposed to the pathogen. This phase could take three years or more and depends on the virus remaining active long enough for participants to be exposed to it.

Unfortunately, while vaccines are in development, there is little we can do in terms of protecting ourselves against the new coronavirus, except for practising physical distancing and regularly washing our hands.

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