Written by Helena Mello
The COVID-19 vaccines rollout in mid-December introduced us to new terms, techniques, and—perhaps most importantly—brought many questions. We had never followed the development of a vaccine, or even a drug, so closely and anxiously. Many people don’t know how vaccines actually work, except that they protect you from getting very sick or in some cases from getting the disease at all. To clarify the science of COVID-19 vaccines, David Levine from SWINY (Science Writers in New York) spoke with vaccine expert Dr John Moore, professor of microbiology and immunology at Weill Cornell Medical College, on January 21, 2021. The virtual conversation is freely available here.
Dr Moore answered common questions people have about the COVID-19 vaccines, including how they work, how they differ from each other, and their safety.
What is the principle of COVID-19 vaccine?
Coronaviruses get their name from the crown-like structure that surrounds the viral particle (corona is latin for crown). All vaccines granted emergency approval and others currently under development target the Spike (S) protein, a major component of the virus’s crown (turquoise structure surrounding viral particles in the figure). Dr Moore explained that the S protein stands out from the viral particle, making it an easy target for our neutralizing antibodies. The main goal of vaccines is to induce our immune cells to produce antibodies to neutralize the virus if we ever come in contact with it.
“Novel Coronavirus SARS-CoV-2” by NIAID is licensed with CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/
If the purpose is the same, why are there so many different types of vaccine?
We should think of vaccines as transportation devices, Dr Moore answered. All vaccines are tools to deliver the S protein inside our immune cells and stimulate the production of antibodies against that protein. Different vaccines use different delivery vehicles to achieve this, including mRNA, attenuated virus, and adenovirus. The first COVID-19 vaccines approved (Pfizer/BioNTech and Moderna) are mRNA vaccines. These deliver the Spike protein gene to cells so that they can produce the viral protein. Despite being the first mRNA vaccines ever approved for human use, the scientific technology behind them has been well studied and extensively characterized for over 10 years. Other technologies are also important players in the vaccine run, especially considering geographical and economic limitations of each country. For example, doses that require ultracold storage are not suited for areas with limited access to ultracold freezers.
Do we know how safe the COVID-19 vaccines are?
If you are a scientist, you have probably heard this question several times from friends and family. Although we don’t know the long-term effects of the COVID-19 vaccines, the benefits of vaccination significantly outweigh the risk of a SARS-CoV-2 infection. As more people get vaccinated, researchers can follow the immune response in millions of individuals over time and work to improve current vaccines. As Dr Moore importantly pointed out several times throughout this event: “Until we learn more, behave exactly the same.”
About the author: Helena Mello is a PhD Candidate at Rutgers University studying how a tumor virus wakes from latency and spreads around the body. She is committed to translating science into understandable, relatable, and meaningful information for various audiences. Helena is engaged in mentoring the next generation of scientists, with a particular interest in international students.