The development of the first covid vaccines may have seemed to occur at a dizzying pace. After all, scientists identified a new virus and created vaccines to protect against its most severe effects within a .
But the research underpinning these vaccines isn鈥檛 that new at all, vaccine experts say. Some of it is decades old. This foundation, combined with technical expertise, urgency and financial resources, enabled scientists to pull off the medical marvel.
“The reason it was so fast is money and work,鈥 said Dr. Paul Offit, director of the Vaccine Education Center at the Children鈥檚 Hospital of Philadelphia.
Leveraging mRNA: A Technique as Old as Millennials
Covid mRNA vaccines use the human body鈥檚 natural immune response to its advantage. The shot contains the recipe for making the molecule known as the spike protein, which the covid virus uses to bind to cells. Once the cell receives these instructions, it creates the protein and displays it on its surface. The immune system then spots the unknown protein and makes antibodies to fight it.
The vaccines made by the companies Pfizer-BioNTech and Moderna use this technology, which stems from research that began in the early 鈥90s, said Dr. Drew Weissman, a professor of medicine at the University of Pennsylvania. It has been tested against other viruses Scientists learned from previous clinical trials and have since worked to perfect the use of mRNA, he said. Previous work on related coronaviruses like helped speed the process.
Weissman and his colleague , a senior vice president of , are credited with the that enabled these vaccines to be safe and highly effective.
“This isn’t new technology,鈥 Weissman said.
Viral Vector Vaccines: A Health Emergency Veteran
The third vaccine being distributed in the United States to protect against severe covid-19 uses viral vector technology to generate an immune response. It contains a weakened form of a different virus that carries instructions for cells to make the spike protein found on SARS-CoV-2, the virus that causes covid. The protein appears on the cell鈥檚 surface, and the immune system creates antibodies against it.
Like the mRNA vaccines, this technology carries the code for making the spike protein to the cell, said Dr. Ruth Karron, director of the Center for Immunization Research at Johns Hopkins University.
鈥淭he truck is different,鈥 she said, 鈥渂ut what’s being delivered is very similar.鈥
Viral vector technology has been studied . These vaccines have been approved for use to immunize people against Japanese encephalitis. Johnson & Johnson, which uses this platform for its covid shot, also created a viral vector vaccine for Ebola after a in 2019 in the Democratic Republic of the Congo.
Are They Safe?
In addition to existing research, generous resources were allocated to quickly create the covid vaccines, experts said. As of Dec. 2020, the federal government spent $12.4 billion alone on to hasten vaccine development. Drug companies partnered with the National Institutes of Health to tap into its expertise and quickly enroll trial participants.
Perhaps most important, the final clinical trials for the covid vaccines enrolled between 30,000 and nearly 45,000 participants.
鈥淭hese studies are so much bigger than the studies we do for many licensed vaccines,鈥 Karron said. Some trials for previously approved vaccines have included as few as 3,000 participants, she added.
Dr. Scott Ratzan, who runs a covid-19 vaccine communications initiative called at the City University of New York, said pushing certain information has helped assuage fears among the vaccine hesitant. These include highlighting the reality of the virus, comparing the shot鈥檚 side effects to other vaccines and showing the vaccines鈥 effectiveness in millions of people.
Waiting for others to get the shot first was 鈥渁 fair thing鈥 when they first rolled out, Offit said. However, after nearly in the United States have received at least one vaccine dose with no sign of safety issues, he said, the skepticism should be fading away.
鈥淵ou have your proof in terms of efficacy and safety,鈥 Offit said. If you are still refusing, 鈥渢hen that鈥檚 because you鈥檙e not a skeptic anymore. You鈥檙e a cynic.鈥
