Available vaccines use sophisticated mRNA technology that prompts the immune system to mount a protective response against the virus.
After more than a year living with the threat of COVID-19, hope is in sight: a vaccine. Typically, vaccines are not developed, tested and distributed in such a short timeframe, which has led many people to question the vaccine’s safety and efficacy. “There is a fair amount of vaccine hesitancy in the community, including in healthcare,” said Versiti Blood Research Institute Interim Director and Senior Investigator Roy Silverstein, MD. But there is reason to be optimistic.
Old vaccine technology
Vaccine technology has come along way from its early days. In the past, vaccines for diseases like the flu, hepatitis and polio were based on the virus itself, modifying it so that it was no longer infectious. The technology worked—and still works—but, according to Dr. Silverstein, development and production processes are slow, usually involving growing large amounts of the virus in a laboratory setting and then in a production facility. Scientists perform this work yearly for the flu vaccine; other vaccines like hepatitis C have taken as long as 30 years from the time the disease was discovered to identification of the viral strain that causes it, to a vaccine to stop its spread.
New vaccine technology
Instead of using these older vaccine technologies, the COVID-19 vaccine uses modern biotechnology based on synthetic (man-made) messenger RNA (mRNA). In January 2020, Chinese scientists identified the sequence of RNA for COVID-19 and published it so that it could be widely studied. Researchers all over the world conducted sophisticated testing to understand which protein on the virus was the most critical for infection. In the case of COVID, it turned out to be the spike protein.
The COVID-19 mRNA vaccine works by encoding the production of proteins, which are the working parts of cells and viruses. White blood cells process the mRNA and the immune system makes antibodies to the viral proteins and trains other cells, including T cells, to mount a response against it. “If the body sees a virus that has that protein on its surface, it immediately recognizes that virus through the antibodies and T cells and works to destroy that virus before it can do harm,” Dr. Silverstein said. “The vaccine was engineered to target that. It sounds like it went really fast, but it went so quickly because the technologies were in place, primed and ready to go.”
Unlike older vaccine technology, mRNA does not require growing large amounts of the virus in a lab and is created in a way that makes it more stable, easier to handle and longer lasting in the body. “When COVID-19 was identified, the infrastructure was already in place to create a messenger RNA-based vaccine,” Dr. Silverstein said. “It hadn’t been done on a mass scale, but it had been tested in a variety of situations with various types of viruses. There is a lot of really sophisticated technology behind this.”
Ensuring vaccine safety
For many diseases, it can take years or even decades to develop an effective vaccine. However, because the infrastructure was already in place to develop an mRNA vaccine, COVID was so prevalent, and the need was so great, it was easier to accelerate the process. “The scientists who developed the vaccine went through all of the steps in the process that they would with old-fashioned vaccine technology,” he said. “But because of the new technology and how prevalent the virus is, they could complete each step a lot faster.”
Both vaccines currently available in the United States have been approved for emergency use authorization by the Food and Drug Administration (FDA). “These vaccines have undergone rigorous review by internal scientists at the FDA and an external committee,” Dr. Silverstein said. “They both came to the conclusion that the vaccine is safe and highly effective, preventing up to 95% of cases of COVID.”
“There is a great public health value in individuals getting the vaccine,” he continued. “Not only do you protect yourself from the virus, you protect your family, neighbors and friends, and you contribute to herd immunity, which would help eliminate the virus. You’re being a good citizen of the world by getting vaccinated.”
Battling COVID in the future
However, Dr. Silverstein thinks that it will be at least a year before we are able to achieve herd immunity, making it important for investigators at Versiti Blood Research Institute and around the world to continue researching COVID-19 and similar viruses. “There is still a great need to continue researching the virus,” he said. “The more we learn about how it works, how it stimulates the immune system, how the immune system reacts to it, and how our body reacts to it, the better prepared we’ll be for other viruses.”
“Preventing COVID altogether is the best thing we can do,” he continued. “But research around COVID is still valuable and may potentially lead to new drugs for SARS viruses. The more we learn about this, the better prepared we are and the better toolkit we’ll have for treating patients who get sick.”
COVID has had a profound impact on everyone’s lives, and Dr. Silverstein said that we do ourselves and our families a favor by getting vaccinated. “The vaccine is the light at the end of the tunnel,” Dr. Silverstein said. “It’s a true light—not the light of an oncoming locomotive. But it’s only going to work if people take it.”
About the expert: Roy Silverstein, MD, is the interim director and a senior investigator at Versiti Blood Research Institute. He is the John and Linda Mellowes Professor and Chairman in the Department of Medicine at the Medical College of Wisconsin.