How the North-West outbreak informed one of the first studies into long-COVID

August

It’s been more than three years since Tasmania’s North-West was gripped by an outbreak of COVID-19, resulting in a public health emergency.

Between March 20 and April 13 of 2020, there were 138 COVID-19 cases linked to the North West Regional Hospital at Burnie, North West Private Hospital and the Mersey Community Hospital.

This was prior to the development of COVID-19 vaccine and therefore represents a cohort of individuals experiencing primary infection to the original Wuhan strain of SARS-CoV-2.

The spread of the COVID-19 pandemic across the world led to an unprecedented response from the global research community in the pursuit to find an effective treatment and a vaccine for the virus.

Tasmania has played a key role in this, specifically out of the Tasmanian Vaccine Trial Centre at the Launceston General Hospital.

This includes some of the first insights into ‘long-COVID’, with many of the North-West healthcare workers who contracted coronavirus during this outbreak volunteering to participate in a collaborative research study.

Led by the LGH’s Director of Infectious Diseases, Professor Katie Flanagan, the study involved the collection of blood samples from people involved in the NW outbreak, in addition to samples collected from COVID-19 patients in Melbourne.

At the time of commencing this study, very little was known about the long-term effects of COVID-19 on the immune system. The study therefore focused on diverse immunological factors including immune cells, DNA structure and autoantibodies.

This study compared the immune responses of people who had fully recovered from COVID, those with ongoing symptoms, and those who were working at the NWRH during the outbreak, but didn’t experience COVID-19.

Sample analysis remains ongoing, but a study published in the journal Frontiers in Immunology tested reactivity to a panel of 102 disease-specific autoantigens and 6 SARS-CoV-2 antigens to examine the relationship between COVID-19 and autoreactive immunity.

Calprotectin was the most commonly recognised antibody (22.6% of the COVID-19 volunteers), and reactivity to it was associated with return to healthy normal life post-COVID-19.

This suggests that it may play a protective role against developing long-COVID.

Professor Flanagan said future studies may address whether these autoantibodies may provide functional protection.

“Interestingly, the COVID-19 individuals had antibodies to Omicron variant spike protein many months before this variant existed, demonstrating that immunity to the original Wuhan strain of SARS-CoV-2 provides protection against later variants, before they emerge,” she said.

“The identification of autoantibodies as potentially protective indicates a need to not only explore the induction of autoimmunity post COVID-19, but to understand specific targets that may be involved in pathology or protection.

“Future analysis investigating the longitudinal antibody response to antigens identified in this study and their correlation with disease severity and outcomes, may give insights into the roles of autoantibodies in long-COVID.”

The Tasmanian cohort of this study was funded by the Clifford Craig Foundation.