Explainer: Facts about COVID-19 vaccines
[This article was published in August 2020. An update is underway.]
[點擊查看本文中文版]
By Stephanie Chan and Joshua Lee
As of August 12, more than 20 million people have been infected with COVID-19, and more than 700,000 have died.
Some countries like New Zealand and Taiwan have managed to control the spread while other countries like the United States and Brazil struggle to contain the highly contagious virus.
Many experts believe the development of a safe and effective vaccine will be key to stopping SARS-Cov-2, the coronavirus that causes COVID-19.
However, there have been confusion and misleading claims about vaccines since the beginning of the pandemic.
Annie Lab looked into how vaccine development works in an attempt to clear up this confusion.
What are vaccines? What is vaccination?
Vaccination is a method of protecting people from diseases before they actually come into contact with them.
In other words, vaccines are designed to protect people from infection, rather than cure them once an infection occurs.
They are normally injected into the body, although some vaccines can be administered orally or through a nasal spray. (Source: WHO)
How does a vaccine work?
A vaccine achieves immunity from diseases by training the body’s immune system to produce antibodies to fight against the pathogens that cause infectious diseases.
Antibodies are proteins produced by the body to neutralise and destroy invading pathogens.
When a person is exposed to a pathogen after they have been vaccinated against it, their body knows how to produce the correct antibodies to fight the infection and prevent disease. (Source: WHO)
How are vaccines developed and tested before use? How long does it usually take to develop a new vaccine?
There are multiple stages of vaccine development, each with different objectives. Not all vaccine candidates make it past all stages of development. The failure rate is high and many vaccine candidates never make it to clinical trials in humans.
Vaccine development is usually a very time-consuming process. Some reports say it can take 15 years to fully develop and begin distributing a safe and effective vaccine.
But given the urgency of the pandemic, many vaccine developers are speeding up the development process in the hopes of getting an effective COVID-19 vaccine to the market more quickly.
This means researchers and manufacturers are conducting multiple stages and development activities simultaneously, rather than waiting for the successful completion of one stage in the process.
For example, animal testing could be occurring at the same time as phase one clinical trials in humans.
Some manufacturers are also beginning to mass-produce vaccine candidates before they have been proven in order to build up stock, according to a New England Journal of Medicine article.
It is worth noting that existing research into vaccines for Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) has helped accelerate the development, according to Mayo Clinic, a non-profit medical center, as the two viruses are closely related to COVID-19.
How much does it cost to bring a vaccine from development to market?
Researching and developing a vaccine can be very expensive. Estimates vary, but one academic paper suggests that it costs between US$200 to $500 million to bring a vaccine from the concept stage to market.
How will a vaccine help stop the spread of COVID-19?
A vaccine would help stop the spread of COVID-19 by stimulating the immune system to produce corresponding antibodies to fight it.
Most of these vaccines help train the immune system to develop antibodies that attach onto spike proteins and stop the virus.
A successful vaccine for the SARS-CoV-2 coronavirus would teach people’s immune systems to make antibodies against the virus without causing disease. (Source: Mayo Clinic & Nature)
Vaccines have helped with the eradication or reduction of infectious diseases in the past. For example, the development of a vaccine led to the eradication of the virus that causes smallpox.
What is herd immunity?
If the proportion of people who are immune to infection becomes large enough, it would lead to a decline in the rates of infection.
Herd immunity would also be helpful because certain sectors of the population may not be able to get vaccinated for various reasons such as age, allergies or difficulty accessing healthcare services.
However, if enough people around them have immunity, these individuals receive is indirect protection. (Source: Oxford Academic)
How many vaccines are in development? What is the progress of vaccine development right now?
Scientists are developing more than 100 coronavirus vaccines using a range of techniques, including some that are well-established and others that have never been approved for medical use before.
As of Aug. 12 there are 28 vaccine candidates undergoing clinical trials, according to WHO. Of these, six have reached phase three clinical trials. In addition, there are some 139 vaccine candidates undergoing preclinical evaluation.
In Russia, a locally-developed vaccine has been fast-tracked and approved for use by Russian authorities, as announced by President Putin on Aug. 11, 2020. Some experts have expressed doubts about the vaccine’s safety and effectiveness given its quick development.
What are the different approaches to vaccine development?
Scientists are taking many different approaches to developing SARS-CoV-2 vaccines. There are at least four different vaccine technologies being explored to develop a vaccine for COVID-19.
Are the vaccines effective for all kinds of people?
Researchers say vaccines may be less effective for people who are obese. Some people also have health conditions that make them poor candidates for vaccination.
What are some misleading claims surrounding vaccine development?
- Bill Gates is not trying to implant trackers through vaccines.
This common conspiracy has been debunked by many journalists around the world. - The vaccine trial volunteer in the U.K. is alive.
Another popular debunked story claimed a participant in a vaccine trial in the U.K. died after receiving a shot. This was later proven to be false. Microbiologist Elisa Granato, the participant said to be dead, appeared in a video interview with the BBC on April 26, 2020. - Vaccination will not lead to infection.
Another common claim is that any future COVID-19 vaccine will cause the vaccinated person to become infected with the virus. Although vaccines do contain some portion or versions of viruses, the virus is altered and designed in such a way that they will not cause disease or infection.
Disclaimer: This is a student work. Although JMSC faculty members have done everything possible to verify its accuracy, we cannot guarantee there are no mistakes. If you notice an error or have any questions, please email us at contact@annieasia.org.
