Researchers in Finland have conducted a study showing that the neutralizing antibodies generated following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – the agent that causes coronavirus disease 2019 (COVID-19) – generally persist for at least a year.
“Studies of individuals who have recovered from natural SARS-CoV-2 infection are crucial in determining how long antibodies persist and whether these antibodies might protect against re-infection,” writes Anu Haveri and colleagues from the Finnish Institute for Health and Welfare in Helsinki.
Now, the team has shown that in a cohort of more than 360 recovered individuals, immunoglobulin G (IgG) antibodies binding the wild-type SARS-CoV-2 spike protein persisted in 97% of patients for at least twelve months.
The viral spike protein is the main structure the virus uses to infect host cells and a primary target of antibodies following infection or vaccination.
Furthermore, neutralizing antibodies against SARS-CoV-2 also persisted in 89% of individuals for at least a year. “This strongly suggests that protection against re-infection is long-lived,” write the researchers.
By contrast, neutralization capacity was significantly decreased against the B.1.1.7 (alpha), B.1.351 (beta), and B.1.617.2 (delta) variants of concern that arose in the UK, South Africa and India, respectively.
However, the team points out that while re-infection could occur in the absence of neutralizing antibodies, cellular immunity has been shown to less affected by mutations present in these variants and will likely provide long-term protection against severe disease.
