HIQA advises NPHET that immunity post-infection lasts up to six months

Date of publication:

The Health Information and Quality Authority (HIQA) has today published its advice to the National Public Health Emergency Team (NPHET) on the duration of immunity (and protection from reinfection) following SARS-CoV-2 infection.

This advice was informed by international evidence including five large cohort studies and expert opinion, from the COVID-19 Expert Advisory Group.

Dr Máirín Ryan, HIQA’s Deputy CEO and Director of Health Technology Assessment, said: “We have advised NPHET that presumptive immunity should be extended to six months post-infection. The risk of reinfection with SARS-CoV-2 during that period is very low and no evidence was found to suggest that immunity wanes over this period.”

The current guidance in Ireland is that immunity following infection lasts for at least 12 weeks.

Dr Ryan continued: “Our advice has implications for a number of policy areas including exemption from close contact status, serial testing in selected work settings and testing prior to admission or transfer to a healthcare facility. ”

The studies HIQA identified were all conducted prior to December 2020. Since then, a vaccine roll-out has begun and there has been widespread identification and reporting of new variants of SARS-CoV-2. Therefore, the applicability of the findings to the new strains and vaccinated populations is unknown. HIQA’s report cautioned that the advice may not apply to some groups, including the elderly and those who are immunocompromised.

This advice is accompanied by an evidence synthesis report.

HIQA will continue to review the question of immunity and monitor the latest international evidence and national surveillance data.

You can find these documents from the link at the top of the page.


Further information:
Marty Whelan, Head of Communications & Stakeholder Engagement
01 814 7480/085 805 5202, mwhelan@hiqa.ie

Notes to Editor:

  • HIQA has today published or updated the following documents to inform NPHET’s response to COVID-19:
    • Advice to the National Public Health Emergency Team: Duration of immunity (and protection from reinfection) following SARS-CoV-2 infection
    • Evidence summary: Duration of immunity (and protection from reinfection) following SARS-CoV-2 infection.
  • This is the fifth review HIQA has completed on the topic of immunity and reinfection.
  • NPHET asked HIQA to provide advice on the following research question:
    • “How long does protective immunity (that is, prevention of antigen or RT-PCR confirmed reinfection) last in individuals who were previously infected with SARS-CoV-2 and subsequently recovered?”
      • Evidence from five large cohort studies, including three studies that enrolled healthcare workers that examined the risk of SARS-CoV-2 reinfection over time were assessed to respond to this question.
      • This evidence was supported by a second review that included five studies which evaluated the long-term (at least six months post infection) duration of immune response following infection with SARS-CoV-2.
  • HIQA provides evidence-based advice to NPHET to inform public health policy, advice and practice in the context of COVID-19. HIQA’s advice is informed by research evidence developed by HIQA’s COVID-19 Evidence Synthesis Team.
  • This advice to NPHET is developed with expert input from HIQA’s COVID-19 Expert Advisory Group. HIQA’s COVID-19 Expert Advisory Group is a multidisciplinary group, comprising nominated representatives from the relevant public health and clinical specialties, methodology experts, and public representation.
  • The topics HIQA researches are outlined and prioritised by NPHET to ensure rapid access to the best available evidence relevant to the SARS-CoV-2 outbreak.