The Health Information and Quality Authority has published evidence showing that mass temperature screening at airports is not likely to be effective in limiting the spread of Covid-19.

Further evidence published by HIQA this morning, reveals it is still unclear if long-term immunity to the virus causing Covid-19 is possible. It says new studies suggest it may be possible to be reinfected.

HIQA has put together two summaries of evidence, to support the National Public Health Emergency Team, following a request from NPHET's Clinical Expert Advisory Group.

The first deals with the issue of non-contact thermal screening, and whether this could be used to identify cases of Covid-19.

The studies examined by HIQA were conducted in the context of points of entry such as airports, so it is not clear if they would have relevance to community settings such as schools.

HIQA says mass screening using devices such as infrared thermal scanners, were not found to be effective in identifying infectious individuals or limiting the spread of the disease.

It says detection rates were consistently low across the studies.

Latest coronavirus stories

HIQA's Deputy CEO and Director of Health Technology Assessment Dr Máirin Ryan said such screening had been used in other respiratory disease outbreaks such as the swine flu pandemic in Asia and Australia, in 2009, to improve detection.

It involves a combination of temperature testing as well as self-reporting of symptoms and any exposure risk.

But, she said, the evidence clearly showed that it was likely to be ineffective in limiting the spread of Covid-19.

She said detection rates are very low because of the large numbers of cases that are asymptomatic. Many people are infectious before showing symptoms or do not have a fever.

The second evidence summary published by HIQA, looks at the immune response following infection with the virus.

Dr Ryan said it remained unclear whether long-term immunity to SARS-CoV-2, was possible.

An antibody specific to the virus was detected in almost all individuals up to three months after being infected.

And over 90% of patients had developed a neutralising antibody response. But she said a handful of new studies suggested it may be possible to be reinfected with the virus.

Dr Ryan said HIQA would continue to monitor the evidence on immunity and update its summary as required.