Monkeypox vaccination
In response to a shortage of the JYNNEOS vaccine for monkeypox, the FDA on August 9, 2022, issued an emergency use authorization for smaller, intradermal injections (within the skin) in place of a full subcutaneous dose (between the skin and muscle). SciLine asked experts about this and other potential options to broaden access to the limited supplies of vaccine.
Reporters can use the video clips, audio, and comments below in news stories, with attribution to the scientist who made them.
What are Quotes from Experts?
August 10, 2022
What factors should individuals consider when deciding whether to seek vaccination against monkeypox?
Ellen Carlin, D.V.M.
“People should be thinking about this in terms of CDC guidance and health care provider guidance. The CDC is recommending the vaccine for people who have been exposed to monkeypox, and also for close contacts of people who have been diagnosed with monkeypox. The thing to remember is that this vaccine is only available to governments. It’s not available commercially. And so anyone who wants it has to adhere to whatever the eligibility requirements are in their jurisdictions. And so this is a third area that’s important, in addition to the CDC and health care providers, what are the eligibility criteria in a person’s local jurisdiction. In some cases they may actually be wider than the CDC’s guidance.” (Posted August 10, 2022 | Download Video)
Ellen Carlin, D.V.M.
Assistant research professor, Center for Global Health Science & Security, Georgetown University
Jason Kindrachuk, Ph.D.
“When we’re talking about monkeypox vaccination I think again we have to go back and reflect on what are the current recommendations for vaccination in the community, but also consider where are we seeing an overrepresentation of cases. That continues to be within the men who have sex with men community as well as with gay men and bisexual men. We are seeing cases overall across the globe being overrepresented over and over again within those communities. So when people are considering vaccination, we have to consider that we want to have, basically, representation of those groups and a high prioritization of people in those groups getting vaccinated.” (Posted August 10, 2022 | Download Video)
Jason Kindrachuk, Ph.D.
Assistant professor of medical microbiology & infectious diseases, Max Rady College of Medicine, University of Manitoba
Rachel Roper, Ph.D.
“Well, right now the vaccine supply is limited, so we really want people to get vaccinated who are high risk. And right now that’s men who have sex with men, and especially multiple partners.” (Posted August 10, 2022 | Download Video)
Rachel Roper, Ph.D.
Professor of microbiology and immunology, Brody School of Medicine, East Carolina University
Given the limited supply of the JYNNEOS vaccine for monkeypox, what does the research say about the effectiveness of a smaller dose in an intradermal injection, rather than a full dose in a subcutaneous injection, as permitted under the new FDA emergency use authorization?
Ellen Carlin, D.V.M.
“To answer this question about the efficacy of this lower dose, intradermal route, the FDA is going off of a 2015 study in which they looked at a group of volunteers who got the vaccine at this lower dosage and through the intradermal route. And essentially what they found is that the antibody responses in those individuals were similar in the people who received the injections in the labeled way—the way that’s indicated on the JYNNEOS label. And so reasonably the FDA is concluding that this could be a good solution to this perceived shortage of the vaccine. It’s important to remember that this was a small study, only about 150 people or so in that arm of the study. We don’t fully know what this means for long-term protection, and we don’t fully know what it means for safety. We do know that there was a higher incidence of injection-site reactions in this cohort of people. So the NIH is going to be launching a study in real time in the monkeypox outbreak to help get more answers to some of these questions.” (Posted August 10, 2022 | Download Video)
Ellen Carlin, D.V.M.
Assistant research professor, Center for Global Health Science & Security, Georgetown University
Jason Kindrachuk, Ph.D.
“We’ve seen a recent movement in regards to trying to do some dose sparing, and trying to go down from two doses of the JYNNEOS vaccine down to one dose—or even go to the intradermal route and have a lower vaccine dose being delivered. We can go back to some of the data that’s been acquired for smallpox vaccines and monkeypox virus vaccines: ACAM2000, which was the prior vaccine that already had approval—it’s a live, replicating vaccinia virus—and then JYNNEOS, which is the live, non-replicating vaccinia virus.
“What we can do is we can compare between those to look at immune responses. We know there’s no clinical efficacy data for humans in monkeypox trials. But what we do have is comparatives in regards to immune response. And what’s important is that even a single dose or even the dose sparing strategies have given similar immune responses as what we have seen previously with ACAM2000.” (Posted August 10, 2022 | Download Video)
Jason Kindrachuk, Ph.D.
Assistant professor of medical microbiology & infectious diseases, Max Rady College of Medicine, University of Manitoba
Rachel Roper, Ph.D.
“Well, with an immunization it’s good to use a large dose of antigen. But if you have a limited supply of the vaccine and you need to vaccinate a lot of people, decreasing the dose and changing the way that it’s administered is a good way to deal with that problem.” (Posted August 10, 2022 | Download Video)
Rachel Roper, Ph.D.
Professor of microbiology and immunology, Brody School of Medicine, East Carolina University
What does the research say about the effectiveness of giving one full dose of JYNNEOS instead of the recommended two?
Ellen Carlin, D.V.M.
“When JYNNEOS was going through clinical trials, the company and the FDA evaluated the data at multiple time points. This included looking at antibody responses after one dose and after two dose. And the antibody is what is going to protect people in an outbreak. And there was a pretty robust response after one dose. So it’s not unreasonable to think that it could be protective. But there was a higher response after the second dose. And that’s why this vaccine was approved in a two-dose regimen. What’s happening now is that it’s being used in a real-world scenario of people who are being exposed to potentially high levels of the virus through they way they’re getting exposed. And ultimately it’s still an unknown whether one dose is going to be really protective in that circumstance.” (Posted August 10, 2022 | Download Video)
Ellen Carlin, D.V.M.
Assistant research professor, Center for Global Health Science & Security, Georgetown University
Jason Kindrachuk, Ph.D.
“We have to appreciate very much that the data that we have right now on smallpox vaccines, certainly from 1980 on after the eradication of smallpox and because of, obviously, ethics and ethical considerations for doing monkeypox trials in humans, we don’t have a lot of human efficacy data. We have good monkey data from studies in nonhuman primates. Those studies have told us that even after a single dose of the JYNNEOS vaccine, we actually see very robust immune responses. I think that really has been the telltale sign, and it’s that we again can compare back against other trials that have been done and we can see that, repeatedly, that single dose appears to offer some protective benefit. We don’t know the full cascade of immune response, but it tells us something.” (Posted August 10, 2022 | Download Video)
Jason Kindrachuk, Ph.D.
Assistant professor of medical microbiology & infectious diseases, Max Rady College of Medicine, University of Manitoba
Rachel Roper, Ph.D.
“The JYNNEOS vaccine isn’t as strong as the ACAM2000, the other one, but one dose will provide significant protection. Certainly we want to give both doses if possible, but one dose is a million times better than no dose.” (Posted August 10, 2022 | Download Video)
Rachel Roper, Ph.D.
Professor of microbiology and immunology, Brody School of Medicine, East Carolina University
What role might the older ACAM2000 smallpox vaccine have against monkeypox, given the shortage of JYNNEOS?
Ellen Carlin, D.V.M.
“ACAM2000 did show protectiveness in monkeys against monkeypox during pre-clinical trials. Unfortunately this vaccine has a lot of side effects. It’s not approved for monkeypox. It’s only approved for smallpox. I think it’s pretty unlikely that this vaccine will be approved for the current outbreak, unless the outbreak got much, much worse and we were in a really emergent situation where we needed a lot more dosages of a vaccine that could be protective against monkeypox.” (Posted August 10, 2022 | Download Video)
Ellen Carlin, D.V.M.
Assistant research professor, Center for Global Health Science & Security, Georgetown University
Jason Kindrachuk, Ph.D.
“I think that there is a potential role for ACAM2000. We have to appreciate there are limitations in who can receive the ACAM2000 vaccine. Those are mostly based on contraindications we already knew about, people that had underlying skin conditions, people that were immunocompromised, and as well those below the age of eighteen. But what we have to appreciate right now is we have a limited supply of JYNNEOS, so if there’s a mechanism for us to be able to get ACAM2000 out to populations that can receive the vaccine, but also that we can provide monitoring for those that receive the vaccine and ensure that there is good messaging in regard to what types of symptoms that they may encounter, this could be something that could help us continue to get it under control, not only here but also globally where there is still monkeypox impact.” (Posted August 10, 2022 | Download Video)
Jason Kindrachuk, Ph.D.
Assistant professor of medical microbiology & infectious diseases, Max Rady College of Medicine, University of Manitoba
Rachel Roper, Ph.D.
“The ACAM2000 vaccine is very strong, very effective. It’s been given to a lot of humans. The problem is its safety profile. It’s not that safe for immunocompromised people, people that have had a history of eczema, for pregnant women, so it’s got a much worse safety profile than the JYNNEOS.” (Posted August 10, 2022 | Download Video)
Rachel Roper, Ph.D.
Professor of microbiology and immunology, Brody School of Medicine, East Carolina University
Ellen Carlin, D.V.M.
Jason Kindrachuk, Ph.D.
Rachel Roper, Ph.D.
Ellen Carlin, D.V.M.
Assistant research professor, Center for Global Health Science & Security, Georgetown University
Dr. Carlin is a veterinarian and public health expert in infectious diseases. Prior to Georgetown, she worked in numerous scientific and policy roles including as professional staff with the U.S. House Committee on Homeland Security. She reports that she consults through a strategy group for Bavarian Nordic, which manufactures a monkeypox vaccine, and was previously employed by the company.
Jason Kindrachuk, Ph.D.
Assistant professor of medical microbiology & infectious diseases, Max Rady College of Medicine, University of Manitoba
None.
Rachel Roper, Ph.D.
Professor of microbiology and immunology, Brody School of Medicine, East Carolina University
Dr. Roper is a virologist and immunologist. She serves on the International Committee on Taxonomy of Viruses (ICTV), the American Society for Microbiology Inclusive Diversity with Equity, Access, and Accountability (IDEAA) Committee of the Board, the Viral Bioinformatics Research Centre, and is co-chair of the Global Virus Network Monkeypox Task Force (all volunteer). She has been funded by the U.S. National Science Foundation and National Institutes of Health and served on numerous grant study sections to evaluate grant proposals. She holds patents on poxvirus virulence genes and improved vaccine strategies (not related to the current poxvirus vaccines). She was previously funded by Boehringer Ingelheim, Inc. between 2/1/11 – 1/30/15 for her work on Raccoonpoxvirus Virulence and Genomics: Improved Poxvirus Vaccines.
