In a recent study published in The Lancet Microbe, CAMS Oxford Institute Principal Investigators Prof. Bin Cao & Prof. Jianwei Wang have led a study following patients who recovered from a COVID-19 infection across a two year period. They evaluated the presence of IgG antibodies, neutralising antibodies, and memory B-cell and memory T-cell responses against the prototype strain and delta and omicron variants.
As a novel viral infection from 2019, longitudinal data on immune responses to SARS-CoV-2 are only now beginning to emerge. Data like that shown in this paper is important for both understanding of immune responses to the virus, but also for informing political and strategic decisions on vaccination protocols.
In this study the researchers found that neutralising antibody responses continually declined across the two year period. Even if antibodies were present, they were not able to recognise and neutralise the omicron variants, now the most dominant circulating strain, of the virus well at all. However, encouragingly memory B-cell responses to the original strain were retained at 2 years and presented cross-reactivity to the delta and omicron BA.1 variants. The magnitude of interferon γ and T-cell responses to SARS-CoV-2 were not significantly different between 1 year and 2 years after infection.
The authors suggest that with the increasing emergence of variants, effective vaccines should be introduced to boost neutralising antibody and overall T-cell responses to newly emerged SARS-CoV-2 variants.
Read the full article here.