New research on coronavirus published in the journal medRxiv revealed that coronavirus can persist up to 140 days i.e. 20 weeks post-infection.

Researchers conducted a study that included 880 people from Northern Ireland. The samples were collected across Northern Ireland between April and July 2020.

The researchers then carried out immunoassays — a procedure for detecting or measuring specific proteins or other substances through their properties as antibodies — to see the level of antibodies in participants.

The authors of the study noted that IgG antibodies to both the spike protein and nucleocapsid protein are persistent even after 140 days after RT PCR positive status.

The authors, however, reported a statistically significant decline over time, but the levels remain detectable at 140 days. They also noted that the levels of antibodies reach their peak as late as week 8-12 post-infection.

Longitudinal studies on SARS-CoV convalescent patients suggested that detectable IgG can still be present as long as two years after infection, the study added.

The authors believe that further studies are needed on large cohorts with sequential antibody immunoassays performed on symptomatic and non-symptomatic individuals as well as those with mild and severe Covid-19.

The researchers added that further studies are vital to informing vaccine durability, so-called ‘immune passports’, and in the definition of a protective threshold for anti-SARS-CoV2 antibodies. This also supports the use of the immunoassays for seroprevalence screening.

Researchers wrote that for individuals, it may cause anxiety. However, a positive antibody test will help arrest infection spread.

In conclusion, the researchers report the longevity of antibodies against the SARS-CoV-2 virus in the plasma of a large cohort of individuals — lasting up to 140 days.

The authors had developed a ‘pseudo gold standard’ reference cohort to assess immunoassay performance.