COVID-19 antibodies remain in blood for at least eight months after infection: Study

Antibodies against coronavirus remained in the blood of patients with COVID-19 for at least eight months after they were infected, Italian researchers said on May 11. According to a statement from the San Raffaele hospital in Milan, the researchers said that the antibodies were present regardless of the severity of the illness, the age of the patients or the presence of other pathologies. In a press release, the researchers, working with Italy’s ISS national health institute, analysed 162 patients with symptomatic coronavirus who turned up at the emergency room during the country’s first wave of infections last year. 

The scientists took blood samples of COVID-19 patients in March and April last year and then again in November from those who survived. In a statement, the researchers said that the presence if neutralising antibodies, while reducing overtime, was “very persistent” even after eight months after diagnosis. However, they also noted that there were only three patients who no longer showed positivity to the test. 

“Neutralizing antibodies against SARS-CoV-2 persist in symptomatic patients for up to at least 8 months after the diagnosis of Covid-19,  regardless of the severity of the disease, the age of the patients or the presence of other diseases,” the statement read. 

Moreover, the research also emphasised the importance of the development of antibodies in recovering from coronavirus. They said that those who failed to produce the antibodies within the first 15 days of infection are at “greater risk of developing severe forms of COVID-19”. The researchers noted that two-thirds of the patients surveyed were men, and the average age was 63. Some 57 per cent of them had a pre-existing pathology, hypertension and diabetes. 

Reactivation of antibodies to seasonal coronaviruses

As per the press note, the researchers also went on to investigate the reactivation of antibodies to seasonal coronaviruses in patients with aim of verifying their impact on the response against SARS-CoV-2. They said that the antibodies to seasonal coronaviruses partially recognize the new coronavirus and can reactivate following the infection, although they are not effective in neutralizing it. The researchers added that the fear was that their expansion could slow the production of neutralizing antibodies specific for SARS-CoV-2, with negative effects on the course of the infection. 

“According to the data analyzed by the San Raffaele researchers, however, reactivation of pre-existing antibodies to seasonal coronaviruses has no influence in delaying the production of antibodies specific to SARS-CoV-2 and is therefore not associated with an increased risk of severe COVID-19 courses,” the press release read. 

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