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A rare COVID-19 variant that has been detected in multiple patients across Angola and Sweden during Spring 2021 may be extremely successful at evading vaccine-induced antibodies, suggests a recent study published in Nature Molecular and Cellular Immunology. First detected in Tanzania in February, the A.30 variant may pose a distinct threat in a world becoming increasingly reliant on vaccines to protect against coronavirus, but remains isolated for now.
A.30 is an offshoot variant from the A lineage, which is the lineage thought to be the root of the pandemic and among the first to be identified. However, it is markedly distinct from other variants, compared in this study to variants Beta (B.1.351) and Eta (B.1.525), by multiple mutations in the Spike protein. Notably, some of these mutations reside in two separate domains directly targeted by neutralizing antibodies, suggesting the vaccine may not perform as well against A.30 compared to other variants.
Currently, there are very few sequenced cases of A.30, with 3 sequences from Angola and 1 sequence from Sweden since its discovery in Tanzania. As such, very little research has been conducted on the variant.
To discover how dangerous the variant may be, researchers from Göttingen, Germany, used multiple human cell lines to study how successfully the virus can infect host cells, before subjecting it to neutralizing antibodies that develop post-vaccination to see if they still hold the same efficacy against the mutations A.30 carries.
Compared to Beta and Eta, A.30 showed significantly improved entry into most host cells, including kidney, liver, and lung cells, and was resistant to a monoclonal antibody therapy currently employed against COVID-19 (bamlanivimab); however, it was vulnerable to combined therapy of other monoclonal antibodies (bamlanivimab and etesevimab).
When tested against vaccine-induced antibodies from the Pfizer-BioNTech and Oxford-Astrazeneca vaccines, A.30 was more resistant than the other variants tested at evading them, suggesting a reduced efficacy of the vaccines (although these are in vitro experiments that may not necessarily translate to real-world efficacy).
The researchers conclude that this variant may be more adept at entry into cells, while possessing a toolkit to effectively evade current vaccines. Such results suggest A.30 should be closely monitored in the coming months and countries should prioritize preventative measures that would stop an outbreak if A.30 were to become more widespread.
It is currently not classified as a Variant of Interest or Concern by the WHO, likely owing to its low prevalence.
