Mutants and the Validity of SARS-CoV-2 Antigen Test kit
The Sars-Cov-2 has underwent several significant mutations after detected in 2019. And many doubt whether the current rapid test kits can detect the mutants. Technical study and clinical studies shows that our Sars-Cov-2 Antigen test kits can detect the variants.
1. Variant P.1
Variant P.1 was first identified in Japan amongst travelers from Brazil. The P.1 lineage is a descendant of B1.1.28, and contains 17 unique amino acid changes, three deletions, four synonymous mutations, and one 4nt insertion. Three of these mutations are of known biological importance: K417T, E484K, and N501Y.
2. VOC1 (Kent, UK) & VOC2 (South Africa)
The VOC1 (Kent, UK) and VOC2 (South Africa) both contain multiple nucleotide changes across the genome which result in amino acid substitutions and other changes in different proteins. These include a large number of changes in the spike protein and a lesser number in the nucleocapsid protein.
3. B.1.617 & B.1.618
Highly transmissible SARS-CoV-2 variants identified in India are named B.1.617 and B.1.618. They have mutations in spike proteins, which may contribute to their increased transmission and may lead to reinfection or resistance to vaccine induced antibodies. B.1.617 encodes a spike protein with mutations of L452R, E484Q, D614G and P681R, while B.1.618 encodes a spike protein with mutations of Δ145-146, E484K and D614G mutations.
Recently, a new novel coronavirus variant B.1.1.529 has been reported by the World Health Organization (WHO) and named Omicron. It was first discovered in South Africa. The Omicron strain had more mutations in the spike protein than the other variants. The details of the mutation are still being studied.
Changes in all Mutants
The changes in all the variants for these antigen targets are listed in the table below.
|Variant||VOC 1 (Kent, UK)||VOC2 (South Africa)||B.1.617/B1.618 (India)||Omicron (South Africa)|
|N501Y; A570D; D614G; P681H; T716I; S982A; D1118H; 69/70 HV deletion; 144Y deletion||D80A, D215G, K417N, E484K, N501Y, D614G, A701V||B.1.617: L452R, E484Q, D614G, P681R
B1.618: Δ145-146, E484K and D614G mutation
|D3L; R203K; G204R; S235F||T205I|
Declaration on Validity to the Mutants
Our COVID-19 antigen detection kits, including NOVAtest ® SARS-Cov-2 Antigen rapid test (nCov-500) and FASPIT TM saliva antigen rapid test (C2103) adopt nucleocapsid proteins as the antigen targets. In other word, the target proteins of our antigen test kits have not changed; and the antibodies in our reagents can immunologically bind to the target antigens in the mutants. Therefore our products can detect all the new variants, including Omicron; and the performance of our COVID-19 antigen test kits is not affected by the current detected variant changes.