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Covid-19 HSE Clinical Guidance and Evidence

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About - HSE Repository for Interim Clinical Guidance intended for the Clinical Community

This site provides a national easily-accessible repository of clinical guidance to equip the clinical community in Ireland with the requisite information whilst working within the current COVID-19 environment. 

The site contains and enables access to:

  • HSE Interim Clinical Guidance to provide nationally consistent advice to the clinical community in response to the COVID-19 national health emergency, and as core services resume is inclusive of guidance for the provision of both COVID-19 care and non COVID care in a COVID environment.  Guidance is based on best available knowledge at the time of completion, written by clinical subject matter experts (SMEs) working with the HSE.  These SMEs have both expertise and experience of treating patients for the specific health conditions covered by the guidance.
  • Summaries of Evidence prepared by the HSE National Library Evidence team and other stakeholders (these are statements of emerging evidence and do not replace clinical judgement or guidance)
  • An online facility to request additional published COVID-19 evidence in relation to specific clinical questions

Interim Clinical Guidance published on this site is under the governance of CCO CAG.  This guidance takes into consideration advice provided by NPHET relating to the current COVID-19 health emergency. 

The content of the site is not meant to replace clinical judgment or specialist consultation, but rather strengthen clinical management of patients and provide up-to-date and relevant guidance.  The guidance is iterative in nature and is subject to ongoing review to ensure alignment with emerging evidence and updates to national guidelines.  This guidance must be read in conjunction with the National HSE Infection Prevention and Control (IPC) Guidance for Possible or Confirmed COVID-19 

Submit Covid-19 Summary of Evidence Request

Latest - Summaries of Evidence

Updated page: 10/09/21
How long does immunity last after COVID-19 vaccination? Does immunity wane faster in certain sub-populations? How safe and effective are booster doses of COVID-19 vaccine?
Main Points​​
  1. Data from vaccination campaigns and ongoing studies have not fully answered the question of how long protection from COVID-19 vaccines will last. Data on the impact of new SARS-CoV-2 variants are limited, but are expected soon. Data from an ongoing multinational pivotal efficacy study showed that despite a gradually declining trend in vaccine efficacy, the Pfizer-BioNTech vaccine had an acceptable safety profile and was highly efficacious in preventing COVID-19 up to 6 months post-vaccination.
  2. In Britain, the Joint Committee on Vaccination and Immunisation (JCVI)4 recommend an additional dose of COVID-19 vaccine for those who are severely immunosuppressed. To date, the JCVI has not recommended booster doses for other groups.
  3. In the United States, the Advisory Committee on Immunization Practices (ACIP) recommend that individuals with certain immunocompromising conditions who received a two-dose mRNA vaccine series should receive a third dose of the same vaccine. Immunocompromising conditions that warrant a third dose include active use of chemotherapy for cancer; hematologic malignancies; hematopoietic stem cell or solid organ transplant; advanced or untreated HIV infection with CD4 cell count <200 cells/microL; moderate or severe primary immunodeficiency disorder; and use of immunosuppressive medications.
  4. Patients receiving dialysis may mount an attenuated immune response to COVID-19 vaccination. Standard vaccination series provide insufficient protection to some haemodialysis patients; immune monitoring and adaption of vaccination protocols may be considered.
  5. Individuals aged ³60 years will need to be closely monitored and may require earlier booster vaccinations to ensure long-lasting immunity and protection against infection.
  6. Solid-organ transplant recipients may develop a substantially lower immunological response to mRNA-based vaccines. Data indicate that administration of a third dose of vaccine to solid-organ transplant recipients significantly improved immunogenicity.
  7. There is significant heterogeneity of humoral immune response to COVID-19 vaccines among immunosuppressed individuals, highlighting an urgent need to optimize COVID-19 prevention in these patients.


Produced by the members of the National Health Library and Knowledge Service Evidence Team. These literature reviews collate the best available evidence at the time of writing and do not replace clinical judgement or guidance. Emerging literature or subsequent developments in respect of technologies may require amendment to the information or sources listed in the document. Although all reasonable care has been taken in the compilation of content, the National Health Library and Knowledge Service Evidence Team makes no representations or warranties expressed or implied as to the accuracy or suitability of the information or sources listed in this document. These literature reviews are the property of the National Health Library and Knowledge Service and subsequent re-use or distribution in whole or in part should include acknowledgement of the service.


This collection of literature reviews was created between April and July 2020 by members of the National Health Library and Knowledge Service Evidence Team to support the Health Service Executive National Telehealth Steering Group. Each literature review relates to innovations in telemedicine as applicable to a specific condition or specialty and each is presented as a separate chapter. Additional studies relating to specific conditions or specialities may be added by the Evidence Team as individual chapters are revised and updated. Additional chapters relating to additional conditions or specialities may be added by the Evidence Team.

Using combinations of the subject headings and keywords set out in Appendix 1, the databases CINAHL, EMBASE and Medline were searched and search results filtered for studies published between 2015 and 2020, in English, relating primarily to adult populations and with an emphasis on systematic reviews and randomised controlled trials. Each chapter presents the evidence as illustrated below. Within each section, studies are arranged in reverse chronological order by year and, within a year, in alphabetical order by author surname. Please see Appendix 2 for an alphabetical list of sources referenced per condition or specialty. Please see Appendix 3 for an alphabetical list of all sources referenced.

Definitions: According to the OED, ‘telehealth’ is defined as the provision of health-care services remotely by means of telecommunications technology; the term was first recorded in 1975. ‘Telemedicine’ is defined as medicine practised with the assistance of telecommunications technology, often to provide care in remote locations or to reduce the need for hospital visits; the term was first recorded in 1968. ‘Mobile health’ is defined as health and medical services provided and accessed primarily using smartphones and mobile devices; the term was first recorded as such in 2000.

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