BACKGROUND: Coronavirus disease of 2019 (COVID-19) is a pandemic that the world is still not able to treat, vaccinate, or manage. In medical history, vaccines were the best option against viral infections. This article proposed the possibility of using the nonstructural proteins (NSPs) of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as sources of vaccine material by extracting the NSPs peptides (particularly the small-sized NSP11 and NSP7), from a feasible and abundant protein: Albumin.

MATERIALS AND METHODS: The databases of SWISS-MODEL and Uniprot were used to compare NSPs sequences with sequenced proteins, including Albumin. Similarities in sequences between severe acute respiratory syndrome Coronavirus and severe acute respiratory syndrome coronavirus-2 were excluded; also, homologies of less than 20% were omitted.

RESULTS: Albumin has no homology to any of the SARS-CoV-2 NSPs. The highest value of similarity between SARA-CoV-2 NSPs and a non-coronavirus protein was the 49% similarity of NSP4 with RNA Polymerase of mouse hepatitis Virus. A tetramer (or a trimer) of NSP11 has 29% similarity with the Human Astrovirus-2 capsid protein spike domain. NSP7 has no homology with any known sequence protein other than the coronaviruses proteins. Other resemblances of the SARS-CoV-2 NSPs to known sequenced proteins were 31% or less, and these were to proteins from human, bacterial, and viral sources.

CONCLUSIONS: The extraction of SARS-CoV-2 NSPs from albumin is unlikely to occur because of absent sequence similarities. There are only partial homologies of nonstructural proteins to proteins from humans, bacteria, or other viruses.