Close up of a scientist drawing up a blue solution with a syringe
The novel coronavirus, SARS-CoV-2, is the virus that causes COVID-19, a disease that has upended the entire world. Scientists have been working tirelessly to develop a COVID-19 vaccine. To control infection and also prevent further spread, entire nations are invested in the development of a safe, effective, and viable vaccine. The timeline of the pandemic has been rapid, but so, too, has been the race to an effective and safe vaccine. Nidhi Parekh of The Shared Microscope and Sheeva Azma of Fancy Comma, LLC have summarized the key takeaways you need to know to understand the COVID-19 vaccine race. Read on to better understand the journey to a COVID-19 vaccine and the top contenders in this important endeavor. When might a COVID-19 vaccine be available?
Things are heating up in the vaccine race. Several vaccines are in the clinical trials process, and many have reached Phase 3, the last stage before FDA approval. In late July, biotech company Moderna became the first to begin Phase 3 trials in the United States as a part of Operation Warp Speed, the US government’s effort to speed up the research and development process for a COVID-19 vaccine. Worldwide, Phase 3 trials were already underway when Moderna began Phase 3 trials in the US -- the Oxford/AstraZeneca vaccine has been in Phase 3 trials since early July in countries like Brazil and South Africa.
Top US White House science advisor, Anthony Fauci has predicted that a COVID-19 vaccine will be commercially available by early 2021. However, the US Food and Drug Administration (FDA) has the power to grant Emergency Use Authorization (EUA) status to vaccines well before then, if they are deemed safe and effective (to be used in high-risk populations, for example). A variety of technologies and innovative approaches are being used in the race against the novel coronavirus pandemic. Because the entire world will need to obtain this vaccine, it is likely that many of these candidates will obtain approval in order to be quickly manufactured and distributed. In this post, we'll briefly discuss the vaccines from Moderna, Oxford/AstraZeneca, Sinovac, and Novavax. Defining Viruses and Vaccines
Generally speaking, viruses cannot survive outside of a host. In the case of the SARS-CoV-2 virus that causes COVID-19, the virus uses humans as a host. Because COVID-19 is very infectious and spreads via respiratory droplets — such as by talking to someone without wearing a mask — the novel coronavirus was able to spread and proliferate worldwide.
When a virus infects a cell of the host, it is able to take over and use the resources of the host to replicate. After replication, the virus takes over the host cell to assemble new viral particles and infect more host cells. Vaccines help stop the spread of viruses by helping humans develop immunity to them. Vaccines are used to introduce vital information about pathogens like bacteria and viruses to the body, in order to train the immune system to prevent future infection. SARS-CoV-2 Spike Proteins are an Attractive Target for COVID-19 Vaccines
Structure of the SARS-CoV-2 virus - the novel coronavirus that causes COVID-19. Photo by CDC on Unsplash.
SARS-CoV-2 causes infection in people via spike proteins found on its surface. The infection that the virus causes is called COVID-19. The virus’s spike proteins help the virus interact with cells in our lungs (as well as other organs and even, perhaps, the lining of our blood vessels), to eventually enter and infect these cells. Once the SARS-CoV-2 virus is in our cells, thanks to the spike proteins, the virus can rapidly multiply and cause COVID-19 infection. Since spike proteins are vital to causing COVID-19 infection, the majority of vaccines in development are aimed at the spike proteins as a way to prevent a COVID-19 infection.
Three out of four of the top COVID-19 vaccine contenders (Moderna, Oxford, and Novavax) target the novel coronavirus's spike proteins, whereas a vaccine in development by Beijing-based biotech company, Sinovac focuses on culturing the virus in bulk and then “killing” or inactivating it with the use of heat or chemicals. These vaccines will all be further discussed in this article. There are even more vaccines under development: you can check out the New York Times’ vaccine tracker for the latest COVID-19 news and updates. Below, we discuss four of the main contenders for a COVID-19 vaccine. Moderna mRNA-1273: A Nucleic Acid Vaccine
Moderna Therapeutics is a biotech company based just steps away from Sheeva’s alma mater, MIT, in Cambridge, MA (USA). Moderna’s vaccine is based on molecular “messages” called messenger RiboNucleic Acid or mRNA. This messaging system is commonly used by the body to produce all the proteins necessary for survival.
The mRNA vaccine in development by Moderna contains instructions needed for our body to produce the SARS-CoV-2 spike proteins. When naturally infected at a later date, our body will have the tools necessary to scavenger-hunt the SARS-CoV-2 spike proteins as “foreign” entities and eliminate them. In other words, the vaccine will help our bodies develop immunity against the spike proteins. The Moderna mRNA-1273 vaccine is currently in Phase 3 trials in the United States. To learn more about the vaccine, please check out this article. Oxford/AstraZeneca ChAdOx1-nCov19 (AZD1222): A Viral Vector Vaccine
Oxford University in the UK has teamed up with AstraZeneca (also with corporate headquarters in the UK) to create a novel vaccine that is currently in Phase 3 clinical trials globally. Like the Moderna vaccine, the vaccine being developed by Oxford University, too, exploits the SARS-CoV-2 spike protein. This vaccine uses a non-replicating simian adenovirus as a vector - this means that the vaccine uses a replication-defective adenovirus (a type of virus) which causes cold-like symptoms in chimpanzees. The genetic material from this adenovirus is removed and replaced by the information to make only the SARS-CoV-2 spike protein.
Like before, the vaccine introduces vital information of the SARS-CoV-2 spike protein to our bodies, which helps flag the virus as “foreign” when naturally infected by it at a later date. Using the vaccine, our body has learned the viruses “top moves” and has the ability to cancel these. This allows the body to prevent future infection by the SARS-CoV-2 virus. Oxford/AstraZeneca have received approval to complete phase 3 trials in Brazil and South Africa. We hope to receive the results of these trials by Fall 2020. We have previously written about how the Oxford/AstraZeneca vaccine works in more detail, as well as what it's like to participate in the Oxford vaccine clinical trials over at our blog. Novavax’s NVX-CoV2373: A Protein Subunit Vaccine
Novavax is a biopharma company based in Germantown, Maryland (USA), not too far from Washington, D.C. The vaccine in development by Novavax, called the NVX-CoV2373, is a protein subunit type vaccine. This means that the active ingredient of the vaccine is a protein. More specifically, the protein of interest is the SARS-CoV-2 spike protein. The spike proteins used in the Novavax vaccine are grown in the laboratory, and then harvested. The spike proteins are then purified to filter out any unnecessary molecules, and used in a vaccine.
Again, the spike protein will be identified by our bodies as “foreign,” and then an attack will be planned against these proteins, to then ensure safety from any future infections. Novavax has received $1.6 billion in funding from Operation Warp Speed. They have since seen their stock prices rocket from $5 to $130 dollars, making it an attractive target for investors. The vaccine in development by Novavax is currently in simultaneous Phase I/II clinical trials in South Africa. Learn more about Novavax and how it works here. CoronaVac: An Inactivated Virus Vaccine
The CoronaVac vaccine is being developed by Chinese biopharma company Sinovac. CoronaVac contains an inactivated version of SARS-CoV-2. As a vaccine of the inactivated type, this vaccine relies on a tried-and-true method of vaccine development. The COVID-19 vaccine is made from harvesting whole SARS-CoV-2 viruses and then chemically inactivating (killing) them.
The CoronaVac vaccine has received approval to conduct phase 3 trials in Brazil, the results of which are currently awaited. Learn more about CoronaVac here. In the COVID-19 Pandemic, Knowledge is Power
Knowledge is power! This stands 100% true amid a pandemic. Knowledge about the COVID-19 vaccines will help combat misinformation and eradicate dangerous ignorance. While many may be fearful of the new vaccines, building understanding can help reduce fear and anxiety, which are driving anti-vax sentiment that threatens to derail all of humanity’s great efforts to overcome the pandemic and many other preventable life-threatening diseases.
You can learn more about the science of COVID-19 vaccines, and more about the ongoing COVID-19 vaccine trials in general, at the Fancy Comma website.
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