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COVID-19 Vaccine Appears Well-Tolerated and Effective in Developing Antibodies in Small Study of Older Adults

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Bandage after vaccine
Credit: iStock/BackyardProduction

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 [1], 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 [2]. 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.

References:

[1] 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.

[2] “Phase 3 clinical trial of investigational vaccine for COVID-19 begins.” National Institutes of Heath. July 27, 2020

Links:

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)

Safety and Immunogenicity Study of 2019-nCoV Vaccine (mRNA-1273) for Prophylaxis of SARS-CoV-2 Infection (COVID-19) (ClinicalTrials.gov)

NIH Support: National Institute of Allergy and Infectious Diseases

11 Comments

  • Mike Hasan says:

    Very useful information. Loved to read it. Thank you

  • Paula Schum says:

    Thank you for providing this update!

    • Marian P. says:

      This is very encouraging. As a retired Infection Control nurse, I have been anxious to hear of the results of this vaccine trial. As an older citizen, I will be ready to take it as soon as it becomes available.

  • Saramai says:

    Thank you for the information.

  • Jodi Godfrey says:

    Are the findings similar for women v. men? What about racial differences? The NIH should set an example but reporting out on these important outcomes. Unless and until the data offer assurance beyond generalized statements, we cannot evaluate the safety and efficacy of Covid vaccines for the entire population.

  • Steve Kalis says:

    Thank you for the encouraging update

  • John Hasty says:

    It appears that the first publicly available safe and effective immunization against COVID-19 will be from a mRNA vaccine. However it is quite possible that a better more effective vaccine such as a live-attenuated COVID-19 vaccine created by deoptimizing the codon pairs of the virus will take longer to reach the market.

    The question in my mind is how will an initial mRNA injection effect any possible future injection with a live-attenuated vaccine?

  • Manuel Karos says:

    Interesting. I would assume the Data monitoring board would know for sure. The Johnson and Johnson phase lll clinical trial reported an adverse reaction today but failed to give details.

  • A Goldstein says:

    It appears that we are still waiting to learn whether any of the vaccines show that in humans, they are capable of lowering the frequency of new Covid-19 infections or resulting in milder symptoms if infection does occur. Until we know that, we are relying on the animal studies, binding quality of the antibodies formed and the historic correlations between these efficacy surrogates and previous vaccines, to predict actual efficacy. Is that a fair statement?

  • Taushin Hanif says:

    That’s interesting. I ‘d hope the data monitoring board is sure to consider that. The phase-in trial performed by Johnson and Johnson today reported an adverse reaction, but did not provide precise information.

  • MRKRUSS says:

    PLEASE SPEND THE MONEY AND LET THE AMERICAN PUBLIC AND THE WORLD KNOW WHAT A REAL MIRACLE LOOKS IT. I AM BLOWN AWAY THAT THIS CONVERSATION IS NOT AT EVERY DINNER TABLE AROUND THE WORLD AND IN EVERY CLASSROOM AROUND THE GLOBE. I REMEMBER WHEN WE WENT TO THE MOON IN 1969 AND I REMEMBER THE FIRST HEART TRANSPLANT. ANTIBIOTICS WERE RELEASED IN 1942 AND NURSING BECAME A SCIENCE IN THE 1830’S BY FLORENCE NIGHTINGALE. ON A SCALE OF 1-10, THE NIH GETS A 1,000,000. BRAVO!

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