Implications of B.1.1.7 on the viral character and immune of vaccines

The United Kingdom and Northern Ireland reported to WHO about the SARS-CoV-2 mutation identified through a viral genome called VUI 202012/01 (Variant Under Investigation, year 2020, month 12, variant 01) or B.1.1.7

What are the implications of the SARS-CoV-2 mutation on the viral, diagnostic, therapeutic and immune effects acquired through vaccination?

B.1.1.7 is a new variant of SARS-CoV-2 which is formed from 23 types of mutations :

• 14 non-synonymous mutations (amino acid changes [AA]).
• 6 synonymous mutations (non-AA).
• 3 deletions with N501Y as the mutation considered to be the most significant.

B.1.1.7 is predominantly patients aged < 60 years and mean age 11-70 years.

Mutation is a natural process that can occur as long as the virus replicates and circulates in humans.

Mutations identified in variation VUI 202012/01 or B.1.1.7 :

N501Y ➡️

• Amino acid mutations that are included in the six key residues in the receptor binding domain (RBD).
• There was a substitution of asparagine (N) spike protein at position 501 receptor binding domain (RBD) with tyrosine (Y).
• Changes in the spike protein can affect the specificity of viral binding to the ACE 2 receptor and thus interfere with antibody recognition.

Mutation of P681H ➡️

• Mutations were found in RBD, near the furin S1 / S2 cleavage site, which is a site of high variability in the coronavirus.

Deletion 69/70 ➡️

• The double deletion occurs spontaneously in the form of a spike protein.
• Deletions can affect the performance of some diagnostic PCR tests that target the S gene and give a false negative reaction. However, because most polymerase chain reaction (PCR) tests have multiple targets to detect the virus, even if a mutation affects one target, the PCR test can still track other targets.

ORF 8 stop codon (Q27 Stop) ➡️

• This mutation is not in the spike protein but in a different gene (open reading frame 8) and its function is not yet known.

There is not enough evidence that VUI 202012/01 or B.1.1.7 infection results in a more severe degree of disease than the SARS-CoV-2 variant.

Various clinical trials are still being conducted to determine whether the B.1.1.7 variant virus has different biological properties, increases the risk of reinfection and decreases the efficacy of the vaccine. Variant B.1.1.7 has a mutation in the spike protein which is the target of various vaccine candidates.

Conclusion.

• All types of viruses can mutate over time, but mutations do not always have a positive impact on the virus itself, some can have a negative impact on the transmission of the virus itself.
• There is not enough evidence to date whether the new variant mutations affect clinical disease severity, antibody response or vaccine effectiveness.
• Further clinical trials are needed to understand the impact of mutations on viral, diagnostic, therapeutic and immune of vaccines.