Ellen Baum, PhD, and Harry Ma, PhD, Janssen Pharmaceutical Companies of Johnson & Johnson

After an “Original” abstract and its corresponding poster have been presented at a scientific or medical congress, publication professionals sometimes face challenges when preparing subsequent “Encore” presentations, and the way forward may not always be obvious. For example, will updates in the Introduction/Background section due to different word count and/or formatting requirements of the “Encore” congress make an abstract “not an encore?” Will these changes require approval by all authors, or just the corresponding author? And if the Original abstract of Congress A is due before Congress B, but presentation of poster B occurs before A, which is the Encore, A or B? Perhaps most importantly, is there an alternative if the target congress does not accept Encores? This article examines available definitions of Encore presentations and discusses some “real world” Encore scenarios and potential ways to handle them.

Original and Encore Presentations: Definitions, Guidelines, and an ISMPP Survey

Not to overstate the obvious, but “Encore” in this context refers to submitting the same data (abstract or poster; Encore oral presentations are relatively rare compared to posters and are not discussed in this article) to a congress after the initial presentation of the Original at an earlier congress (see Table 1 below). Usually the data would be “reproduced exactly” except for minor changes to meet the congress’ specific requirements, such as word count, formatting, translation, and author order.1

Table 1. Presentation Types

Abstract or Poster Type Definition
Original The initial presentation
Encore Original’s data are reproduced except for formatting, word count, or other “trivial” changes.
Adaptation or Repurposed The content overlaps with the Original, but contains new/additional data, analyses, and/or interpretations.

Good Publication Practice-3 (GPP3)2 addresses the topic of Encores only briefly. Encores are permitted provided that: (i) the congress permits it; (ii) copyright requirements are respected; (iii) prior presentations are disclosed; and (iv) repeated presentation is to reach a different audience. In addition, an Encore presentation usually has the same authors as the Original; GPP3 includes an exception to enable presentation in a local language when presentation by a nonauthor is not permitted and provided that all Original authors agree.

In a 2013 survey among ISMPP members (195 participants), Panayi et al.3 examined respondents’ views on Encore presentations (GPP2 was the latest version at that time). Most respondents (71%) agreed that Encore abstracts should be presented “in moderation;” valid reasons for Encore presentations included “different geography” (95%) or “different specialty” (94%). Strikingly, 78% of respondents wanted more guidance on Encores from publication or medical writing professional organizations.

What If a Target Congress Does Not Allow Encore Presentations?

If a target congress does not accept Encore presentations, but there are sufficient reasons (eg, new audience, new geography, etc.) to present the information at that congress, many publication professionals have used a third option that is neither an Encore nor an Original abstract/poster and is known as an “Adaptation”4 or “Repurposed.”1 The content of an Adapted or Repurposed presentation overlaps with the Original but contains new/additional data, analyses, and/or interpretations; therefore, authorship can change relative to the Original.1, 4 By this definition, addition of a new figure or table, for example, would make the Original presentation into an Adaptation/Repurposed, rather than an Encore.

Whereas Original vs. Encore definitions should be clear cut (that is, initial vs. subsequent presentations), the actual requirements to turn an Original into an Adapted/Repurposed abstract and poster fall into what can be considered a “gray area.” Guidance on this topic from professional organizations has been scarce, and it is not addressed in GPP3. A recent preprint on Good Practice for Conference Abstracts and Presentations: GP-CAP included information on encore abstracts and presentations but did not specifically address Adapted/Repurposed abstracts and posters; publication of GP-CAP is pending.5

Copyright Considerations

In the case of abstract copyright, it is not a question of whether Congress B (occurring after Congress A) allows Encore presentations; rather, copyright ownership by Congress A could prevent an Encore at Congress B.

GPP3 points out the need to respect copyright requirements.2 According to the survey by Panayi et al.,3 only 57% of respondents considered the potential copyright of the Original abstract when preparing an Encore abstract. In some cases, authors must transfer copyright to the congress, and it is increasingly common for congresses to publish abstracts in a journal without mentioning copyright transfer.

Congress policies on abstract copyright vary widely; some examples are shown in Table 2 below. A Google search for “(conference OR congress) AND abstract AND copyright” revealed three main types of congress copyright policies:

(i) authors retain copyright (eg, IAC and EADV, Table 2), implying that Encores are permitted at subsequent congresses;

(ii) congress retains copyright (eg, ASH and ASCO, Table 2), indicating that Encores are not permitted; and

(iii) congress retains copyright but suggests that authors contact the congress for permission to re-use (eg, CROI and EHA, Table 2).

For types (ii) and (iii), it is possible that Adaptation/Repurposing as discussed above for Encore abstracts might allow authors to present at subsequent Congress B, despite copyright by Congress A, with Congress A’s permission. It is expected that there would be a corresponding addition of new data, analyses, and/or interpretations to the poster, to accurately reflect the Adapted/Repurposed abstract. Alternatively, substantial rewriting of the abstract might avoid infringing on Congress A’s abstract copyright but allow the essentially identical poster to be presented at Congress B.

 Table 2. Examples of Congress Policies on Copyright Regarding Subsequent Encore Abstracts

Congress Abstract Policy Examples Interpretation of Abstract Policy
American Society of Clinical Oncology (ASCO)6 “The abstract itself may not be released publicly by the company or lead author, as ASCO holds the copyright to the abstract.” Encores at subsequent congresses are not permitted, but possible that Adaptation is allowed; check with ASCO.
American Society of Hematology (ASH) 7 “Authors assign copyright of the abstract to ASH upon submission, unless one of the authors is a U.S. Federal employee (in such case, ASH does not hold copyright). This means that the identical abstract may not be republished or submitted to another meeting.” Encores at subsequent congresses are not permitted, but possible that Adaptation is allowed; check with ASH.
Conference on Retroviruses and Opportunistic Infections (CROI)8


“By submitting your abstract…you are transferring all copyright ownership of the abstract…to the CROI Foundation in the event that the abstract is accepted and published by the CROI Foundation…. We require that permission to replicate or reproduce any part of a CROI abstract be obtained from the CROI Secretariat; however, study data are the property of the author(s) and study sponsors as relevant. For more information, please e-mail …” Unclear if Encores at subsequent congresses are permitted; check with CROI.
European Academy of Dermatology and Venereology (EADV)9 “author will retain copyright of his or her abstract… However, the author shall only reuse, reproduce or post the abstract with acknowledgment to the initial and first publication or presentation at an EADV event…” Encores at subsequent congresses are permitted.
European Hematology Association (EHA)10


“All accepted abstracts are the property of EHA and the EHA Annual Congress Abstract Book is protected by copyright. All rights reserved. No part of the publication may be reproduced (see exceptions below)…without permission in writing from the publisher, the European Hematology Association (EHA)…Authors have permission to do the following after their article or abstract has been published, either in print or online…Reuse figures and tables created by the author in future works. For all other uses, the author must request permission from EHA … Unclear if Encores at subsequent congresses are permitted; check with EHA.
International AIDS Conference (IAC)11 “Authors retain the copyright of their abstracts…” Encores at subsequent congresses are permitted.

Many congress websites do not state a copyright policy, so it is likely that authors retain copyright in those cases. However, if Congress A publishes the abstract without explicitly requiring copyright transfer, it is possible that authors cannot submit the essentially identical abstract to subsequent Congress B. When in doubt, the prudent policy is to contact Congress A to inquire about re-use of the abstract.

What about poster copyright?  In many cases, posters are a “prelude” to developing a manuscript, and it would appear to be counterproductive to prevent authors from re-using their poster content, especially figures and tables. Moreover, unlike abstracts, posters are usually not subject to peer review and not regarded as durable, citable publications. In fact, poster copyright transfer appears to be quite rare: for approximately 75 congresses (comprising oncology, neuroscience, infectious disease, and vaccine therapeutic areas) at which Janssen’s authors presented posters, the publications team found no instance of a requirement to transfer poster copyright to the congress. One extremely rare example found online is the Annual Meeting of the American Academy of Ophthalmology (AAO),12 which states, “The Academy holds copyright on all material presented at the Academy’s annual meeting until and unless such material is found unsuitable for publication in Ophthalmology. Should an author wish to publish his or her material elsewhere, it may not be submitted for consideration until Ophthalmology has released the presenter from any copyright obligations.” The motivation for this policy is evidently to steer the manuscript derived from the poster to the AAO journal, but it would also effectively prevent Encores or Adapted/Repurposed presentations.

Author Approvals on Abstracts, including “Encore Switching”

Implicit in GPP3 guidelines is that ICMJE authorship requirements are mandatory for Original abstracts and Original posters and include author submission signoff. 2 Companies may have their own policies regarding authors’ approval/signoff process for Encores. For example, Janssen’s policy on Encore presentations is that although all authors must be notified of Encore abstracts/posters, only the corresponding author must formally approve Encore submissions in our documentation system. For a Repurposed/Adapted abstract and poster, which is considered “not an Encore,” Janssen’s policy is that all authors must review and approve.

In the situation where Congress A occurs before Congress B, but Abstract A is due after Abstract B, there is a switch of Original and Encore. Abstract B is the Original abstract, but Poster A is the Original poster; they are treated accordingly by Janssen for author signoff (all authors for Original; only corresponding author for Encore).


The definition of Original (initial submission to Congress A) vs. Encore abstract (essentially identical submission to subsequent Congress B) is clear cut. If Congress B does not accept Encores, or if Congress A requires abstract copyright transfer, then it is necessary to explore whether “the gray area” — transforming the Original into an Adapted or Repurposed abstract — is permissible. When in doubt, contact Congress A and/or B as applicable. Finally, as expressed by ISMPP survey respondents,3 guidance on Encores from publication/medical writing professional organizations – but expanded to include the “gray area” discussed herein – would be helpful in elucidating the way forward.

Disclaimer: The ideas presented are those of the authors and not their employer, Janssen Pharmaceutical Companies of Johnson & Johnson.


  1. Ganesan, B. (2014). A Practical Approach to Encores in the Asia-Pacific Region. http://www.ismpp.org/assets/docs/Education/ISMPPU/APAC/apet%20oct%2029%20-%20final.pdf Accessed 11Jun2018.
  2. Battisti, W. et al. (2015). Good Publication Practice for Communicating Company-Sponsored Medical Research: GPP3. Ann Intern Med. 163:461-464.
  3. Panayi, A.E. et al. (2014). A Survey of Current Practices in Encore Abstract Submissions from Industry-Sponsored Study Data. http://www.ismpp.org/assets/docs/Education/EuropeanMeeting/2014EM/GeneralSessionPresentations/oral%20presentations.pdf Accessed 11Jun2018.
  4. Reed, D.M. et al. (2013). Developing an Encore Abstract Process that Complies with GPP. https://ismpp.memberclicks.net/assets/docs/Education/ISMPPU/2013/ismppu_globalpubplanning_5%2022%2013_final.pdf Accessed 11Jun2018.
  5. Foster C. et al. (2017). Good Practice for Conference Abstracts and Presentations: GP-CAP. PeerJ Preprints 5:e3356v1 https://doi.org/10.7287/peerj.preprints.3356v1
  6. https://am.asco.org/abstracts/abstract-policies-exceptions Accessed 14Jun2018.
  7. http://www.hematology.org/Annual-Meeting/Abstracts/2853.aspx Accessed 14Jun2018.
  8. http://www.croiconference.org/abstract-guidelines Accessed 14Jun2018.
  9. https://eadvgeneva2017.org/scientific-information/call-for-abstracts/online-poster-service/ Accessed 14Jun2018.
  10. https://ehaweb.org/assets/Pages/Congress/EHA23-Abstract-Submission-Terms-Conditions-January-2018.pdf Accessed 14Jun2018.
  11. https://www.aids2018.org/Programme/Abstracts/Submission-guidelines Accessed 14Jun2018.
  12. https://www.aao.org/annual-meeting/presenter/submission-policies Accessed 14Jun2018.
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