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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 

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Latest - Summaries of Evidence

Updated page: 17/11/21
Do people with medical comorbidities require a booster dose of COVID-19 vaccine?
Main Points​​
  1. As of 12 September 2021, 13 EU/EEA countries recommend an additional dose as an extension of the primary series to immunocompromised individuals, and 9 countries recommend both an additional dose as an extension of primary series and as a booster dose for waning immunity. In the United States the CDC recommends a booster doses in specific populations including individuals at risk for severe COVID-19 because of comorbidities. In the United Kingdom, the JCVI has advised that individuals in priority groups who received vaccination in the initial phase of the COVID-19 vaccination should be offered a third dose COVID-19 booster vaccine including individuals with underlying conditions that put them at higher risk of severe COVID-19 and the immunosuppressed.
  2. The CDC has categorised the following comorbidities as conditions associated with a higher risk of severe COVID-19, as supported by at least one meta-analysis or systematic review: cancer; cerebrovascular disease; chronic kidney disease; chronic lung diseases limited to interstitial lung disease, pulmonary embolism, pulmonary hypertension, bronchopulmonary dysplasia, bronchiectasis, and chronic obstructive pulmonary disease; chronic liver diseases limited to cirrhosis, non-alcoholic fatty liver disease, alcoholic liver disease, and autoimmune hepatitis; diabetes mellitus; heart conditions such as heart failure, coronary artery disease or cardiomyopathies; mental health disorders limited to mood disorders including depression and schizophrenia spectrum disorders; obesity; pregnancy or recent pregnancy; smoking; tuberculosis.
  3. The CDC has categorised the following comorbidities as conditions associated with a higher risk of severe COVID-19, as supported by lower-level evidence: asthma; certain underlying conditions in children; cystic fibrosis; Down syndrome; human immunodeficiency virus; hypertension; immune deficiencies; neurologic conditions including dementia; overweight; sickle cell disease; solid organ or blood stem cell transplantation; substance use disorders; thalassemia; use of corticosteroids or other immunosuppressive medications.


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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