Posted on by Dr. Francis Collins
The winter holidays are traditionally a time of gift-giving. As fatiguing as 2020 and the COVID-19 pandemic have been, science has stepped up this year to provide humankind with a pair of truly hopeful gifts: the first two COVID-19 vaccines.
Two weeks ago, the U.S. Food and Drug Administration (FDA) granted emergency use authorization (EUA) to a COVID-19 vaccine from Pfizer/BioNTech, enabling distribution to begin to certain high-risk groups just three days later. More recently, the FDA granted an EUA to a COVID-19 vaccine from the biotechnology company Moderna, Cambridge, MA. This messenger RNA (mRNA) vaccine, which is part of a new approach to vaccination, was co-developed by NIH’s National Institute of Allergy and Infectious Diseases (NIAID). The EUA is based on data showing the vaccine is safe and 94.5 percent effective at protecting people from infection with SARS-CoV-2, the coronavirus that causes COVID-19.
Those data on the Moderna vaccine come from a clinical trial of 30,000 individuals, who generously participated to help others. We can’t thank those trial participants enough for this gift. The distribution of millions of Moderna vaccine doses is expected to begin this week.
It’s hard to put into words just how remarkable these accomplishments are in the history of science. A vaccine development process that used to take many years, often decades, has been condensed to about 11 months. Just last January, researchers started out with a previously unknown virus and we now have not just one, but two, vaccines that will be administered to millions of Americans before year’s end. And the accomplishments don’t end there—several other types of COVID-19 vaccines are also on the way.
It’s important to recognize that this couldn’t have happened without the efforts of many scientists working tirelessly behind the scenes for many years prior to the pandemic. Among those who deserve tremendous credit are Kizzmekia Corbett, Barney Graham, John Mascola, and other members of the amazing team at the Dale and Betty Bumpers Vaccine Research Center at NIH’s National Institute of Allergy and Infectious Diseases (NIAID).
When word of SARS-CoV-2 emerged, Corbett, Graham, and other NIAID researchers had already been studying other coronaviruses for years, including those responsible for earlier outbreaks of respiratory disease. So, when word came that this was a new coronavirus outbreak, they were ready to take action. It helped that they had paid special attention to the spike proteins on the surface of coronaviruses, which have turned out to be the main focus the COVID-19 vaccines now under development.
The two vaccines currently authorized for administration in the United States work in a unique way. Their centerpiece is a small, non-infectious snippet of mRNA. Our cells constantly produce thousands of mRNAs, which provide the instructions needed to make proteins. When someone receives an mRNA vaccine for COVID-19, it tells the person’s own cells to make the SARS-CoV-2 spike protein. The person’s immune system then recognizes the viral spike protein as foreign and produces antibodies to eliminate it.
This vaccine-spurred encounter trains the human immune system to remember the spike protein. So, if an actual SARS-CoV-2 virus tries to infect a vaccinated person weeks or months later, his or her immune system will be ready to fend it off. To produce the most vigorous and durable immunity against the virus, people will need to get two shots of mRNA vaccine, which are spaced several weeks to a month apart, depending on the vaccine.
Some have raised concerns on social media that mRNA vaccines might alter the DNA genome of someone being vaccinated. But that’s not possible, since this mRNA doesn’t enter the nucleus of the cell where DNA is located. Instead, the vaccine mRNAs stay in the outer part of the cell (the cytoplasm). What’s more, after being transcribed into protein just one time, the mRNA quickly degrades. Others have expressed concerns about whether the vaccine could cause COVID-19. That is not a risk because there’s no whole virus involved, just the coding instructions for the non-infectious spike protein.
An important advantage of mRNA is that it’s easy for researchers to synthesize once they know the nucleic acid sequence of a target viral protein. So, the gift of mRNA vaccines is one that will surely keep on giving. This new technology can now be used to speed the development of future vaccines. After the emergence of the disease-causing SARS, MERS, and now SARS-CoV-2 viruses, it would not be surprising if there are other coronavirus health threats in our future. Corbett and her colleagues are hoping to design a universal vaccine that can battle all of them. In addition, mRNA vaccines may prove effective for fighting future pandemics caused by other infectious agents and for preventing many other conditions, such as cancer and HIV.
Though vaccines are unquestionably our best hope for getting past the COVID-19 pandemic, public surveys indicate that some people are uneasy about accepting this disease-preventing gift. Some have even indicated they will refuse to take the vaccine. Healthy skepticism is a good thing, but decisions like this ought to be based on weighing the evidence of benefit versus risk. The results of the Pfizer and Moderna trials, all released for complete public scrutiny, indicate the potential benefits are high and the risks, low. Despite the impressive speed at which the new COVID-19 vaccines were developed, they have undergone and continue to undergo a rigorous process to generate all the data needed by the FDA to determine their long-term safety and effectiveness.
Unfortunately, the gift of COVID-19 vaccines comes too late for the more than 313,000 Americans who have died from complications of COVID-19, and many others who’ve had their lives disrupted and may have to contend with long-term health consequences related to COVID-19. The vaccines did arrive in record time, but all of us wish they could somehow have arrived even sooner to avert such widespread suffering and heartbreak.
It will be many months before all Americans who are willing to get a vaccine can be immunized. We need 75-80 percent of Americans to receive vaccines in order to attain the so-called “herd immunity” needed to drive SARS-CoV-2 away and allow us all to get back to a semblance of normal life.
Meanwhile, we all have a responsibility to do everything possible to block the ongoing transmission of this dangerous virus. Each of us needs to follow the three W’s: Wear a mask, Watch your distance, Wash your hands often.
When your chance for immunization comes, please roll up your sleeve and accept the potentially life-saving gift of a COVID-19 vaccine. In fact, I just got my first shot of the Moderna vaccine today along with NIAID Director Anthony Fauci, HHS Secretary Alex Azar, and some front-line healthcare workers at the NIH Clinical Center. Accepting this gift is our best chance to put this pandemic behind us, as we look forward to a better new year.
Coronavirus (COVID-19) (NIH)
Combat COVID (U.S. Department of Health and Human Services, Washington, D.C.)
Dale and Betty Bumpers Vaccine Research Center (National Institute of Allergy and Infectious Diseases/NIH)
Moderna (Cambridge, MA)
Pfizer (New York, NY)
BioNTech (Mainz, Germany)
Posted on by Dr. Francis Collins
A while ago, I highlighted a promising new approach for designing a vaccine against the human immunodeficiency virus (HIV), the cause of AIDS. This strategy would “take the immune system to school” and teach it a series of lessons using several vaccine injections—each consisting of a different HIV proteins designed to push the immune system, step by step, toward the production of protective antibodies capable of fending off virtually all HIV strains. But a big unanswered question was whether most people actually possess the specific type of precursor immune cells that that can be taught to produce antibodies that kill HIV.
Now, we may have the answer . In a study published in the journal Science, a research team, partly supported by NIH, found that the majority of people do indeed have these precursor cells. While the total number of these cells in each person may be low, this may be all that’s needed for the immune system to recognize a vaccine. Based in part on these findings, researchers plan to launch a Phase 1 clinical trial in human volunteers to see if their latest engineered protein can find these precursor cells and begin coaxing them through the complicated process of producing protective antibodies.
Posted on by Dr. Francis Collins
For many of the viruses that make people sick—think measles, smallpox, or polio—vaccines that deliver weakened or killed virus encourage the immune system to produce antibodies that afford near complete protection in the event of an exposure. But that simple and straightforward approach doesn’t work in the case of human immunodeficiency virus (HIV), the virus that causes AIDS. In part, that’s because our immune system is poorly equipped to recognize HIV and mount an attack against the infection. To make matters worse, HIV has a habit of quickly mutating as it multiplies.That means, in order for an HIV vaccine to be effective, it must induce antibodies capable of fighting against a wide range of HIV strains. For all these reasons, the three decades of effort to develop an HIV vaccine have turned out to be enormously challenging and frustrating.
But now I’m pleased to report that NIH-funded scientists have taken some encouraging strides down this path. In two papers published in Science [1, 2] and one in Cell , researchers presented results of animal studies that support what most vaccine experts have come to suspect: the immune system is in fact capable of producing the kind of antibodies that should be protective against HIV, but it takes more than one step to get there. In effect, a successful vaccine strategy has to “take the immune system to school,” and it requires more than one lesson to pass the final exam. Specifically, what’s needed seems to be a series of shots—each consisting of a different engineered protein designed to push the immune system, step by step, toward the production of protective antibodies that will work against virtually all HIV strains.