The Race for a COVID-19 Vaccine: More Questions Answered
Authorization for a COVID-19 vaccine in the US appears imminent, bringing with it a host of concerns including the speed of development, inclusivity of clinical trials, safety of mRNA technology, and how to raise levels of trust in vulnerable populations.
As the US nears authorization for at least 1 COVID-19 vaccine, with a quick rollout hopefully to follow, concerns remain that a certain portion of the population will be reluctant if not outright opposed to being inoculated against the virus. The Infectious Diseases Society of America (IDSA) hosted a vaccine webinar recently featuring 2 frontline vaccine experts available to answer participants’ most pressing concerns about the new COVID-19 vaccines and allay some common fears.
The vaccine experts stressed that 1 of the things making people nervous—the speed at which COVID-19 vaccines have been developed—is actually an extraordinary accomplishment. “It’s one of the things we get excited about as vaccinologists,” C. Buddy Creech, MD, MPH, FPIDS, director of the Vanderbilt Vaccine Research Program at Vanderbilt University and a principal investigator for the phase 3 trials conducted by Moderna and Johnson & Johnson, said. Creech stressed the well-choreographed coordination across researchers who previously focused on vaccines for other viruses but have poured their hearts and souls into COVID-19 this year. “We’ve really called in a ton of resources to recruit as quickly as we can.”
Creech explained that the researchers assumed that positive phase 1 trial results would carry over into phase 3. In anticipation of this success, the normal timeline of vaccine development was compressed as next steps were lined up in an accelerated fashion. But as quickly as the vaccine rollout is occurring, Creech stressed that no steps are being skipped and safety is not being compromised.
The Pfizer and Moderna vaccines—the 2 leading vaccine contenders right now—are based on a messenger RNA, or mRNA, platform. This new type of vaccine technology that induces a person’s own cells to create antibodies has prompted questions about safety, a concern vaccinologists are eager to allay. “RNA is actually quite unstable, which is why the Pfizer vaccine has to be put into the freezer right now,” Kathleen Neuzil, MD, MPH, professor of medicine and pediatrics and director of the Center for Vaccine Development and Global Health at the University of Maryland School of Medicine, said, referring to the need to keep the Pfizer vaccine at minus 70 degrees Celsius until a few days before use. She explained that the instability of the RNA particles mean they don’t get inside our cells or stay in our bodies; they simply do their job and disintegrate.
In response to a question about the administration of a COVID-19 vaccine to pregnant women and children, the researchers relayed that they’re hopeful those populations will be approved for inoculation. “Cleary, we have been advocating to move into [vaccinating] pregnant women and move into [vaccinating] pediatric populations as soon as it is safe,” said Creech. Manufacturers have been waiting for results from developmental and reproductive toxicology (DART) studies undertaken in animals before recruiting pregnant women. However, as 2 out of 3 healthcare workers in the U.S. are female, the choice to get a vaccine while pregnant may end up being made after discussion between a woman and her physician.
Conversation also is taking place regarding confidence in the vaccine among minority populations and underserved communities, which often have had higher levels of distrust toward the medical system given its historic abuses toward people of color and lack of diversity in clinical trials. “It’s [a question] we’re spending a lot of time thinking about on a local as well as national level,” Creech said, emphasizing the efforts being made recruiting trial subjects of different racial and ethnic backgrounds as well as those who have diseases such as diabetes. Creech also discussed the importance of removing barriers to participating in trials and having individual states and jurisdictions use shared language and education. “There’s a great deal of intentionality,” he said.
As far as having participants continue in placebo trials once a vaccine is available for use, the experts agreed that trials likely would undergo modifications such as comparing vaccines against each other or focusing on subpopulations among trial participants. However, as the U.S. still has not authorized a vaccine, and what will be available once authorized will be insufficient for all who seek inoculation, researchers are focused on simply getting the vaccine to the highest-priority individuals. “Our immediate challenge is going to be supply, supply, supply,” Creech said.