Now that there are three COVID-19 vaccines available under emergency use authorization, many are wondering if they will be able to choose one vaccine over the other. Short answer: No. Doctors and public health experts emphasize that people should take the first vaccine offered to them.
The Pfizer-BioNTech and Moderna vaccines use mRNA to fight the virus, and studies showed that they both had efficacy rates of around 95%. In late February, Johnson & Johnson's adenovirus vector vaccine, made in partnership with Janssen Pharmaceuticals, was also approved, though the rates of efficacy were lower.
However, since the vaccines were tested in different environments and are all equally effective at preventing death and hospitalizations, experts emphasize that people should get the first vaccine offered to them.
Is one COVID-19 vaccine better than another?
"The most important thing the vaccine does for you is prevent you from getting so sick that you need to be in the hospital, or that you even potentially die from a COVID infection," said Dr. Marybeth Sexton, an infectious disease expert, hospital epidemiologist and assistant professor of medicine at Emory University in Atlanta, who pointed out that the Johnson & Johnson vaccine was 85% effective against severe disease and that no patients in the trial were hospitalized or died of the coronavirus. "That's the most important number to look at, and (all the vaccines) do very well."
Dr. Bill Moss, a pediatrician and professor of infectious disease epidemiology at the Johns Hopkins Bloomberg School of Public Health in Baltimore, said that the Johnson & Johnson vaccine was tested in South Africa and Latin America, where variants that may decrease vaccine effectiveness have been spotted. It was also tested at a time of high community spread.
"The trial was conducted later in the pandemic where there were more variants and more viral diversity," Moss said. "We have better data on the Johnson vaccine against the variants. ... There was also very intense transmission, certainly in the United States, later in the pandemic, so these are other epidemiological considerations."
"The important thing to remember is that the vaccines were not compared to each other, head to head, so you have no idea how they would perform if you directly compare them to each other," said Sexton. "By the time the Johnson & Johnson vaccine was tested in trials, there was significant spread of these varying strains, and those may have impacted its efficacy."
The different vaccines have different logistics as well: The Pfizer-BioNTech candidate requires two doses and needs to be stored between -80ºC and -60ºC; the Moderna candidate also requires two doses and needs to be kept at around -20°C. The Johnson & Johnson vaccine requires only one dose and requires normal refrigeration, which Moss said will likely make it easier to distribute to remote areas.
Dr. Deborah Theodore, an instructor at Columbia University Vagelos College of Physicians and Surgeons, said that the Johnson & Johnson vaccine could be especially helpful for people who "have difficulty with mobility" or "are not easily able to travel to a vaccination site."
What vaccine should I get?
All experts interviewed for this story strongly recommended that people take the first vaccine made available to them unless they are allergic to specific vaccine ingredients.
"If someone has an opportunity to get vaccinated, do it as soon as possible," said Dr. Jennifer Lighter, a pediatric infectious disease specialist at NYU Langone Health. "Do not wait or hesitate or vaccine shop. The more people we get vaccinated as soon as possible is extremely important. We're in a race against the virus, right? It's not just having the vaccine, it's really getting it into people's arms."
People who have allergies to specific vaccine ingredients or other concerns should talk with their doctors before receiving the vaccine, said Theodore. Sexton noted that the vaccines have been formulated in a way that helps avoid allergic contraindications, including making sure that no latex is included in the vaccine packaging.
"They've been very careful about removing common allergens," Sexton said, adding that people who have a history of severe allergic reactions will often be asked to stay longer after receiving the vaccine to make sure they don't have a reaction. "Unless you're allergic to an ingredient in the vaccine, in most cases they're telling people to go ahead with close monitoring, but people should definitely talk to their doctor if they've got questions."
Will people ever be able to choose which COVID-19 vaccine they get?
It's hard to tell just when people may be able to choose which vaccine they receive, but experts estimated that the country is at least several months from that point.
"It is difficult to predict when there will be enough supply to allow people to choose which vaccine to receive, and even when there is enough supply, choice may be limited by distribution considerations," said Theodore. "However, there are few reasons to choose one vaccine over another ... The 'best' vaccine to get is the one that is available to you the soonest."