The Race To Discover
A COVID-19 Vaccine
As countries search for a swift solution to the COVID-19 pandemic, more than 170 vaccines are being developed by research teams in universities and laboratories around the world. A few of those are already being tried on humans.
Vaccines generally require years of extensive research and testing before reaching clinics. Nevertheless, political and economic pressure has pushed scientists to rush the research and development of a vaccine for COVID-19.
Many breakthroughs have already been announced, but it will take some time for the world to have an effective and safe vaccine.
Why are vaccines important?
The human body often develops lifelong immunity when we have had a disease. But some diseases may lead to serious complications and even death. Vaccines aim to expose the body to an antigen that will provoke an immune response but won’t cause disease. That response blocks or kills the virus if a person becomes infected.
Before reaching clinics, vaccines undergo several stages of development:
- Exploratory stage
- Preclinical stage
- Clinical development
- - In Phase I, small groups of people receive the trial vaccine.
- - In Phase II, the clinical study is expanded and the vaccine is given to people with certain characteristics.
- - In Phase III, the vaccine is given to thousands of people and tested for efficacy and safety.
- Regulatory review and approval
- Quality control
As of August 17, 2020, more than 170 candidate vaccines were being tracked by the World Health Organization (WHO).
The Russian breakthrough
Russia recently announced that it is pushing ahead with plans for the mass production and mass inoculation of its population using Sputnik V, a vaccine whose development was – some scientists claim – surrounded by opacity, a process that could have jumped important safety measures listed in Phase III of a vaccine’s development cycle. Its developers might have been under a great deal of political pressure to be the first to deliver.
One of the main concerns that the international community of scientists has in relation to Sputnik V is an effect called Antibody-Dependent Enhancement (ADE) -- that is, when other versions of a virus hitchhike on the antibodies that were produced by a vaccine. This can make people sicker when infected a second time. This effect is generally detected during Phase III of the vaccine development cycle.
How we develop immunity
When the body notices foreign substances such as virus and bacteria, the immune system works to recognize the invading pathogens and get rid of them. Lymphocytes such as B cells make antibodies that lock onto specific antigens (an antigen is a molecule or molecular structure present on the outside of a pathogen), and T cells destroy infected cells, stopping them from producing more of the virus.
Antibodies can stay in the body for months, sometimes even years, in case the body needs to fight the same pathogen again.
The human body’s immune system can learn to recognize invading pathogens such as COVID-19. This is how it happens:
There are 10 types of COVID-19 vaccine being developed:
This is how some of the vaccines being developed work:
Many existing vaccines are made using the virus itself. This method requires extensive safety testing.
(A) Weakened virus vaccines: The virus is weakened by being passed through animal or human cells until it mutates and becomes less able to cause disease.
(B) Inactivated virus vaccines: The virus is rendered noninfectious through exposure to chemicals or heat.
Viral vector vaccines
Viral vectors are used by molecular biologists to deliver vaccine antigens into cells. Viruses are modified in such a way as to minimize the risk of handling them.
(A) Replicating viral vector vaccines: These are used to provoke an immune response. The coronavirus spike gene is placed inside a viral vector and injected into the body.
(B) Nonreplicating viral vector vaccines: These are generally used to boost immunity in already infected individuals
Nucleic acid-based vaccines are relatively new and are still under development and evaluation. Some studies say nucleic-acid vaccines based on plasmid DNA and RNA have the potential to be safer and more effective than other methods. The methods used to manufacture RNA vaccines are synthetic, thereby avoiding biologic systems. Other advantages of nucleic acid-based vaccines include the simplicity of the vector and the ease of delivery.
(A) DNA vaccine: These use a method called electroporation to create pores in cell membranes to facilitate the uptake of DNA.
(B) RNA vaccine: RNA is encased in a lipid coat so it can enter cells the same way a virus does.
Protein-based vaccines use protein subunits such as spike and M proteins, or empty virus shells, to initiate a protective immune response against the pathogen.
(A) Protein subunit vaccines present a specific, isolated antigen to the immune system without viral particles, initiating an immune response.
(B) Viruslike particles such as empty virus shells can mimic the coronavirus structure and behavior but are not infectious, as they lack the virus’s genetic material.
When will a vaccine be available?
The Coalition for Epidemic Preparedness Innovations (CEPI) said in April that a vaccine may be available under emergency-use protocols by early 2021.
In May 2020, the WHO received $8.1 billion in pledges from 40 countries to support the rapid development of vaccines. It also developed a system that allows the simultaneous, transparent evaluation of several vaccine candidates that have reached clinical trials. This system brought international organizations, universities, pharmaceutical multinationals, and governments together to collaborate on the development of a viable coronavirus vaccine.
The logic behind that effort is that comparing hundreds of vaccine candidates using the same criteria ensures the world gets the best possible vaccine.
Once the vaccine is done, who will get it first?
Tens of billions of dollars are being invested by private corporations and governments, so it’s no wonder there are concerns that the distribution of a viable and effective vaccine may not be done fairly.
The U.K. invested $79 million in the Oxford University vaccine program in exchange for 30 million doses. This program was done in collaboration with AstraZeneca, the multinational pharmaceutical company that promised the United States 300 million doses in exchange for $1.2 billion.
The European Union has also launched a $2.3 billion European Vaccine Strategy to try to ensure that everyone in the bloc has access to a vaccine.
Most likely, the vaccine will first be distributed to populations in affluent countries, with little or no distribution taking place in impoverished and densely populated countries unable to afford the vaccines.