COVID-19 Vaccine Appears Well-Tolerated and Effective in Developing Antibodies in Small Study of Older Adults
Posted on by Dr. Francis Collins
It’s been truly breathtaking to watch the progress being made on a daily basis to develop safe and effective vaccines for SARS-CoV-2, the novel coronavirus that causes COVID-19. Indeed, months sooner than has ever been possible for a newly emerging infection, several promising vaccines are already working their way through Phase 3 studies, the final stage of clinical evaluation. I remain optimistic that we will have one or more vaccines that prove to be safe and effective by January 2021.
But, as encouraging as the early data have been, uncertainty has remained over whether vaccines that appear safe and effective in developing antibodies in younger adults will work as well in older people, too. It’s a critical issue given that older individuals also are at greater risk for severe or life-threatening illness if they do get sick from COVID-19.
So, I’m pleased to highlight some recent findings, published in the New England Journal of Medicine , from an early Phase 1 clinical trial that was expanded to include 40 adults over age 55. While we eagerly await the results of ongoing and larger studies, these early data suggest that an innovative COVID-19 vaccine co-developed by NIH’s Vaccine Research Center (VRC), in partnership with Moderna Inc., Cambridge, MA, is both well tolerated and effective in generating a strong immune response when given to adults of any age.
The centerpiece of the vaccine in question, known as mRNA-1273, is a small, non-infectious snippet of messenger RNA (mRNA). When this mRNA is injected into muscle, a person’s own body will begin to make the key viral spike protein. As the immune system detects this spike protein, it spurs the production of antibodies that may help to fend off the novel SARS-CoV-2.
Earlier findings from the NIH-supported phase 1 human clinical trial found mRNA-1273 was safe and effective in generating a vigorous immune response in people ages 18 to 55, when delivered in two injections about a month apart. Based on those findings, a large Phase 3 clinical trial is currently enrolling 30,000 volunteers, with results expected in the next few weeks . But, given that immune response to many other vaccines tends to grow weaker with age, how well would this new COVID-19 vaccine work for older individuals?
To find out, a team at Kaiser Permanente Washington Health Research Institute, Seattle, and Emory University School of Medicine, Atlanta, expanded the initial Phase 1 trial to include 20 healthy volunteers ages 56 to 70 and another 20 healthy volunteers ages 71 and older. Ten volunteers in each of the two older age groups received a lower dose of the vaccine (25 micrograms) in two injections given about a month apart. The other 10 in each age group received a higher dose (100 micrograms), given on the same schedule.
Here’s what they found:
• No volunteers suffered serious adverse events. The most common adverse events were mild-to-moderate in severity and included headache, fatigue, muscle aches, chills and pain at the injection site. Those symptoms occurred most often after the second dose and in individuals receiving the higher dose of 100 micrograms.
• Volunteers showed a rapid production of protective antibodies against the spike protein following immunization. After the second injection, all participants showed a strong immune response, with production of robust binding and neutralizing antibodies against SARS-CoV-2.
• The higher dose of 100 micrograms safely produced a stronger immune response compared to the lower dose, supporting its use in larger clinical studies.
• Most importantly, the immune response observed in these older individuals was comparable to that seen previously in younger adults.
The researchers will continue to follow the volunteer trial participants of all ages for about a year to monitor the vaccine’s longer-term effects. But these findings provided support for continued testing of this promising vaccine in older adults in the ongoing Phase 3 clinical trial.
There are currently four SARS-CoV-2 vaccines in phase 3 clinical trials in the United States (though two are currently on hold). Trials of two more vaccines are expected start in the next month or two.
It is not known whether all of these vaccines will have the same vigorous immune response in older individuals that has been demonstrated for this one. But if more than one of these vaccines turns out to be safe and effective, it will be important to know about the response in various populations, so that distribution to high-risk groups can be planned accordingly.
 Safety and immunogenicity of SARS-CoV-2 mRNA-1273 vaccine in older adults. Anderson EJ, Rouphael NG, Widge AT, Jackson LA, Roberts PC, Makhene M, Chappell JD, Denison MR, Stevens LJ, Pruijssers AJ, McDermott AB, Flach B, Lin BC, Doria-Rose NA, O’Dell S, Schmidt SD, Corbett KS, Swanson PA 2nd, Padilla M, Neuzil KM, Bennett H, Leav B, Makowski M, Albert J, Cross K, Edara VV, Floyd K, Suthar MS, Martinez DR, Baric R, Buchanan W, Luke CJ, Phadke VK, Rostad CA, Ledgerwood JE, Graham BS, Beigel JH; mRNA-1273 Study Group. N Engl J Med. 2020 Sep 29.
 “Phase 3 clinical trial of investigational vaccine for COVID-19 begins.” National Institutes of Heath. July 27, 2020
Coronavirus (COVID-19) (NIH)
COVID-19 Prevention Network (National Institute of Allergy and Infectious Diseases/NIH)
Dale and Betty Bumpers Vaccine Research Center (National Institute of Allergy and Infectious Diseases/NIH)
Moderna, Inc. (Cambridge, MA)
NIH Support: National Institute of Allergy and Infectious Diseases
Posted on by Dr. Francis Collins
The recent COVID-19 outbreak of a novel type of coronavirus that began in China has prompted a massive global effort to contain and slow its spread. Despite those efforts, over the last month the virus has begun circulating outside of China in multiple countries and territories.
Cases have now appeared in the United States involving some affected individuals who haven’t traveled recently outside the country. They also have had no known contact with others who have recently arrived from China or other countries where the virus is spreading. The NIH and other U.S. public health agencies stand on high alert and have mobilized needed resources to help not only in its containment, but in the development of life-saving interventions.
On the treatment and prevention front, some encouraging news was recently reported. In record time, an NIH-funded team of researchers has created the first atomic-scale map of a promising protein target for vaccine development . This is the so-called spike protein on the new coronavirus that causes COVID-19. As shown above, a portion of this spiky surface appendage (green) allows the virus to bind a receptor on human cells, causing other portions of the spike to fuse the viral and human cell membranes. This process is needed for the virus to gain entry into cells and infect them.
Preclinical studies in mice of a candidate vaccine based on this spike protein are already underway at NIH’s Vaccine Research Center (VRC), part of the National Institute of Allergy and Infectious Diseases (NIAID). An early-stage phase I clinical trial of this vaccine in people is expected to begin within weeks. But there will be many more steps after that to test safety and efficacy, and then to scale up to produce millions of doses. Even though this timetable will potentially break all previous speed records, a safe and effective vaccine will take at least another year to be ready for widespread deployment.
Coronaviruses are a large family of viruses, including some that cause “the common cold” in healthy humans. In fact, these viruses are found throughout the world and account for up to 30 percent of upper respiratory tract infections in adults.
This outbreak of COVID-19 marks the third time in recent years that a coronavirus has emerged to cause severe disease and death in some people. Earlier coronavirus outbreaks included SARS (severe acute respiratory syndrome), which emerged in late 2002 and disappeared two years later, and MERS (Middle East respiratory syndrome), which emerged in 2012 and continues to affect people in small numbers.
Soon after COVID-19 emerged, the new coronavirus, which is closely related to SARS, was recognized as its cause. NIH-funded researchers including Jason McLellan, an alumnus of the VRC and now at The University of Texas at Austin, were ready. They’d been studying coronaviruses in collaboration with NIAID investigators for years, with special attention to the spike proteins.
Just two weeks after Chinese scientists reported the first genome sequence of the virus , McLellan and his colleagues designed and produced samples of its spike protein. Importantly, his team had earlier developed a method to lock coronavirus spike proteins into a shape that makes them both easier to analyze structurally via the high-resolution imaging tool cryo-electron microscopy and to use in vaccine development efforts.
After locking the spike protein in the shape it takes before fusing with a human cell to infect it, the researchers reconstructed its atomic-scale 3D structural map in just 12 days. Their results, published in Science, confirm that the spike protein on the virus that causes COVID-19 is quite similar to that of its close relative, the SARS virus. It also appears to bind human cells more tightly than the SARS virus, which may help to explain why the new coronavirus appears to spread more easily from person to person, mainly by respiratory transmission.
McLellan’s team and his NIAID VRC counterparts also plan to use the stabilized spike protein as a probe to isolate naturally produced antibodies from people who’ve recovered from COVID-19. Such antibodies might form the basis of a treatment for people who’ve been exposed to the virus, such as health care workers.
The NIAID is now working with the biotechnology company Moderna, Cambridge, MA, to use the latest findings to develop a vaccine candidate using messenger RNA (mRNA), molecules that serve as templates for making proteins. The goal is to direct the body to produce a spike protein in such a way to elicit an immune response and the production of antibodies. An early clinical trial of the vaccine in people is expected to begin in the coming weeks. Other vaccine candidates are also in preclinical development.
Meanwhile, the first clinical trial in the U.S. to evaluate an experimental treatment for COVID-19 is already underway at the University of Nebraska Medical Center’s biocontainment unit . The NIH-sponsored trial will evaluate the safety and efficacy of the experimental antiviral drug remdesivir in hospitalized adults diagnosed with COVID-19. The first participant is an American who was repatriated after being quarantined on the Diamond Princess cruise ship in Japan.
As noted, the risk of contracting COVID-19 in the United States is currently low, but the situation is changing rapidly. One of the features that makes the virus so challenging to stay in front of is its long latency period before the characteristic flu-like fever, cough, and shortness of breath manifest. In fact, people infected with the virus may not show any symptoms for up to two weeks, allowing them to pass it on to others in the meantime. You can track the reported cases in the United States on the Centers for Disease Control and Prevention’s website.
As the outbreak continues over the coming weeks and months, you can be certain that NIH and other U.S. public health organizations are working at full speed to understand this virus and to develop better diagnostics, treatments, and vaccines.
 Cryo-EM structure of the 2019-nCoV spike in the prefusion conformation. Wrapp D, Wang N, Corbett KS, Goldsmith JA, Hsieh CL, Abiona O, Graham BS, McLellan JS. Science. 2020 Feb 19.
 A new coronavirus associated with human respiratory disease in China. Wu F, Zhao S, Yu B, Chen YM, Wang W, Song ZG, Hu Y, Tao ZW, Tian JH, Pei YY, Yuan ML, Zhang YL, Dai FH, Liu Y, Wang QM, Zheng JJ, Xu L, Holmes EC, Zhang YZ. Nature. 2020 Feb 3.
 NIH clinical trial of remdesivir to treat COVID-19 begins. NIH News Release. Feb 25, 2020.
Coronaviruses (National Institute of Allergy and Infectious Diseases/NIH)
Coronavirus (COVID-19) (NIAID)
Coronavirus Disease 2019 (Centers for Disease Control and Prevention, Atlanta)
NIH Support: National Institute of Allergy and Infectious Diseases