Editor's Note: (Dr. Seema Yasmin is a medical doctor, epidemiologist, director of the Stanford Health Communication Initiative and author of Viral BS: Medical Myths and Why We Fall for Them. The views expressed in this commentary belong to the author. View more opinion at CNN.)
(CNN) A doctor in Texas once told me that a woman walked into a pediatrician's office in the fall of 2014 and said: "Give my daughter the Ebola vaccine." The biggest Ebola epidemic in history was spreading across West Africa and a man infected with the virus had recently traveled to Dallas.
"There is no vaccine for Ebola," the pediatrician said (the first US Food and Drug Administration-approved Ebola vaccine was announced in December 2019). "But it is flu season and I can give your daughter the flu vaccine." The mother scoffed and said, "Flu vaccine? I don't believe in those things!" before storming out of the doctor's office.
Humans struggle to weigh risk. The flu kills as many as 60,000 Americans a year. But it was fears of an Ebola epidemic in 2014 that forced some schools and businesses to shut, despite the fact that a total of two people died from the virus in the US.
This time around, the new coronavirus that causes Covid-19 has infected 4.5 million people in the US, killed more than 150,000 Americans, and turned our world into disarray. Amid the anxiety and uncertainty, we're forced to make crucial decisions about our health. Should we wear face masks? Should we visit our elderly family members? Should we dine out? And perhaps one day, we'll ask ourselves: Should we be vaccinated?
While a safe and effective vaccine is our best hope for ending this pandemic, only half of Americans said they would roll up their sleeves to get vaccinated, according to a poll from The Associated Press-NORC Center for Public Affairs Research conducted in May. Around 1 in 3 were not sure if they would get vaccinated, while 20% said they would flat out refuse.
Scientists might be wowed by the speed of scientific progress, but a breakthrough will mean little if only half the population ends up getting vaccinated. Some Americans might be rightfully wondering: If it usually takes a decade or longer to develop a vaccine, how are scientists condensing this process down to a year? How can the public be sure that corners are not being cut and safety is not being compromised? And could the President — in an attempt to woo voters in an election year — spin his own "October Surprise" and grant emergency approval of a vaccine that has not been through rigorous safety tests?
While researchers are racing to develop a vaccine, public health officials should be working concurrently on ways to ease these fears. Because transparency is key to building public trust, here's what should be explained about the accelerated vaccine development process.
Vaccine development is a multi-step process that takes a hopeful vaccine candidate tested in a lab to clinical trials in people. The first two phases of human testing focus on studying safety and optimal dosing. Phase 3 trials look at how effective the vaccine is at preventing infection or lessening disease severity.
Some scientists were already working on vaccines for the coronaviruses that cause Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). This gave them a head start when it came to tackling the new coronavirus — which turns out to be very similar to the virus that caused the SARS epidemic in 2002. In fact, the spike protein on the surface of the new coronavirus — the part of the virus that latches on to our cells — is 75% similar to the SARS coronavirus.
Some scientists, such as those at the University of Oxford, are turning to trusted vaccine technology that has been used for years. This includes using a weakened virus (like a common cold virus that typically infects chimpanzees) to introduce a fragment of the new coronavirus. The immune system recognizes the new virus and develops an immune response that could protect against future infection.
Other scientists are turning to much newer vaccine technology. Instead of using parts of the virus's proteins or any weakened viruses, they are putting small parts of the coronavirus genetic code inside microscopic fat particles. The body reads the DNA or RNA and makes small fragments of the virus, which the immune system learns to recognize before building antibodies. This approach saves time by doing away with the need to grow viruses to include in the vaccine. The downside of this approach is that DNA and messenger RNA vaccines have not been approved before, which means the FDA could take longer to assess whether these candidates can go to market.
To further speed up testing, different phases of vaccine trials are being conducted in parallel instead of sequentially. And scientists are collaborating like never before. More than 165 groups around the world are focused on the same virus at the same time, sharing information that could speed up vaccine discovery. Governments and organizations that fund vaccine science have also fast-tracked financing and study approval processes that typically take years.
A vaccine that causes jarring headaches, severe muscle aches, or more serious side effects is unlikely to be popular, even if it protects against an illness like Covid-19.
Information learned at each stage of vaccine testing is shared publicly in peer-reviewed journals so that scientists around the world can track -- and criticize -- vaccine trials. (One of the concerns about Russia's recent announcement that an "approved vaccine" would be available by August 10 is that data from Phase 1 and 2 safety trials has not been shared.) While vaccine trials are ongoing, data monitoring boards review the results so that any red flags are spotted quickly and a trial can be stopped, if necessary.
Checking for safety doesn't end when a vaccine makes it through Phase 3 trials. Safety monitoring continues as the vaccine is used by hundreds of thousands of people around the world. Doctors can collect information on side effects and report new findings to public health authorities through a vaccine safety surveillance program run by the FDA and the US Centers for Disease Control and Prevention.
Safety considerations are key, especially as scientists work at record speed. If a Covid-19 vaccine becomes available, millions of people will face an important decision: Take a vaccine that was developed possibly faster than any other in history, or remain vulnerable to a disease that can cause severe illness and even death.
Like the mother in the Texas pediatrician's office, that choice requires weighing the potential risks while considering personal beliefs and commitment to public health. But it's not a choice we should have to make alone. Researchers, government officials, and initiatives like Operation Warp Speed must help the public make these decisions by peeling back the curtain on vaccine development and offering full transparency.