Scientists from Duke-NUS detected long-lasting immune cells that fight SARS-CoV-2 in the noses of vaccinated individuals who were subsequently infected with COVID-19.
“The SARS-CoV-2 virus initially enters and replicates in the upper respiratory tract, with nasal cells maintaining high levels of virus replication for several days,” said Professor Antonio Bertoletti from the Emerging Infectious Diseases Programme at Duke-NUS, who led the study.
Having this group of virus-fighting immune cells, called T cells, present in the nose could provide an “immediate layer of protection against SARS-CoV-2,” added Bertoletti.
While studying nasal swab samples collected from volunteers, Bertoletti and his team found virus-specific T cells only in the noses of individuals who were infected by SARS-CoV-2 after completing their vaccination.
The nasal-based T cells persisted for at least 20 weeks and recognised various SARS-CoV-2 proteins, reported the group in the Journal of Experimental Medicine. These cells also recognise various viral proteins and will be alerted to variants including the Omicron variant despite its spike protein mutations, ensuring continued nasal-based immunity against SARS-CoV-2.
However, further studies are needed to understand the role of these virus-specific T cells in SARS-CoV-2 protection, and the longevity of these immune cells beyond 20 weeks.