Over the last two weeks, four developers of a COVID-19 vaccine – out of more than 150 programmes currently engaged in a COVID-19 global vaccine race – published the successful results of Phase 1 clinical trials. The frontrunners in this race are: US Biotech firm Moderna, Oxford University with AstraZeneca and, last but not least, Chinese company CanSino and German biotech company BioNTech backed by US drug giant Pfizer.
How does it work? Principles of a vaccine and different types of vaccines
Different approaches to a vaccine
The whole idea behind a vaccine is to stimulate the body’s natural immune response to a virus by skipping it from its lethal characteristics and by giving the human body all the time needed to develop the right antibodies against the intrusive foreign organism.
As the New York Times explains there are basically three different approaches to a coronavirus vaccine.
- Inactivated / Attenuated Virus These vaccines are based on inactivated or weakened forms of the virus for which the vaccine is elaborated . This was the method used in the late XVIIIth to design the first vaccine and it has been generalised from the XIX to the late XXth century following the pioneering work of Jenner, Pasteur, Koch and many other scientists and doctors in their footsteps . Most of the conventional viruses for influenza and other common infectious diseases (measles, smallpox, ) are based on this prophylactic principle
- Non Replicating Viral Vector (NRVV): Basically this is a modern variant of the former approach as it uses another virus called adenovirus which has been modified with the gene of the coronavirus protein spike that needs to be inhibited. Hence it is more complex and requires some genetic engineering but it has proven to be effective for Ebola or HIV as of late.
- Viral Protein based vaccines: This approach is based on the injection of the protein spikes or fragments containing the incriminated proteins which stimulate the immune system to produce the counter-veiling antibodies
- Genetic vaccines (DNA, MRNA): These vaccines are based on the principle of inoculating the gene of the original virus responsible for the production of the spike protein. The human cells can then fabricate this protein either by building a Messenger RNA (MRNA) associated with injected DNA or by receiving directly the MRNA and the related “ready-to-use” instructions to manufacture the proteins. The immune system then detects these proteins and develops targeted antibodies. So far there are no human vaccines using this approach. Moderna’s vaccine candidate -MRNA 1273 – which is one of the four frontrunners outlined in the global race toward producing a COVID-19 vaccine – is an outstanding example of such an innovative approach.
Staggered clinical trials
After preclinical trials on animals, a vaccine has to go through three stages of clinical trials in humans as explained by GAVI:
- Phase 1 with a small number of volunteers 1 to test the vaccine’s safety and effectiveness
- Phase 2 with hundreds of participants split into groups such as children and elderly in randomised trials to further test safety and explore efficacy
- Phase 3 with thousands of participants to test whether there are any rare side effects that only show up in large groups, and also to test how effective the vaccine is and what kind of immune reaction it triggers.
Speeding up the review and approval process for a vaccine
How extensive is the global effort to design a vaccine?
According to the WHO, Researchers around the world are currently developing more than 153 vaccines against the coronavirus in pre-clinical , of which 23 vaccines are in human trials. In the table below we list the later vaccines. The New York Times reviews all the ongoing development effort for vaccines in clinical stages on its COVID-19 vaccine tracker page.
|NRVV||University of Oxford / Astra Zeneca||UK/Brazil/|
|Protein||Anhui Zhufeng / Institute of Microbiology, Chinese Academy of Sciences||China||2|
|MRNA||Cansino / Beijing Institute of Biotechnology||China||2|
|DNA||Inovio Pharmaceuticals/ International Vaccine Institute||US||2|
|DNA||Osaka University/ AnGes/ Takara Bio||Japan||2|
|DNA||Cadila Healthcare Limited||India|
|Inactivated||Wuhan Institute of Biological Products/Sinopharm||China/UAE||2|
|Inactivated||Beijing Institute of Biological Products/Sinopharm||China||2|
|Inactivated||Institute of Medical Biology , Chinese Academy of Medical Sciences||China||1|
|NRVV||Gamaleya Research Institut||Russia||1|
|Protein||Clover Biopharmaceuticals Inc./GSK/Dynavax||EU||1|
|Protein||Vaxine Pty Ltd/Medytox||Korea||1|
|Protein||University of Queensland/CSL/Seqirus||Australia||1|
|MRNA||Imperial College London||UK||1|
|MRNA||People’s Liberation Army (PLA) Academy of Military Sciences/Walvax Biotech.||China||1|
What is the expected release date for a COVID-19 vaccine?
How much will a COVID-19 vaccine cost?
Fairness and affordability vs. profitability
As Suerie Moon, Director of the Global Health Center The Graduate Institute, Geneva writes in the first issue of Global Challenges:
The tension between cooperative public health versus competitive geopolitical imperatives is playing out in the race to develop these health technologies and secure access to them. The strategic manoeuvrings of a wide cast of players highlights how science, industrial capacity and non-state actors are shaping the global order.Suerie Moon, The Vaccine Race: Will Public Health Prevail over Geopolitics?, Global Challenges, Issue 1, June 2020.
She notes on an optimistic tones regarding Europe’s response to the pandemic that on the international level, Europe has emerged as a leader in promoting international cooperation and spearheading the global effort against the pandemic. In Moon’s own words:
The ability to hammer out an agreement bridging the concerns of the US, China and the pharmaceutical industry testifies to Europe’s efficacy as a broker of cooperation.
It is true that by pledging almost €10 billion to ensure global access to drugs, diagnostics and vaccines and by pleading for a balanced approach between intellectual property rights and public health considerations – acknowledging the primacy of the later over the former. Europe has been faithful to its reputation as a posterchild of multilateralism as opposed to the Trump’s Administration unabashed embrace of unilateralism and to an increasingly assertive China that openly displays its ambitions of global leadership.