The Beta variant, (B.1.351), was a variant of SARS-CoV-2, the virus that causes COVID-19. One of several SARS-CoV-2 variants initially believed to be of particular importance, it was first detected in the Nelson Mandela Bay metropolitan area of the Eastern Cape province of South Africa in October 2020, which was reported by the country's health department on 18 December 2020. Phylogeographic analysis suggests this variant emerged in the Nelson Mandela Bay area in July or August 2020.
The World Health Organization labelled the variant as Beta variant, not to replace the scientific name but as a name for the public to commonly refer to. The WHO considers it to be a variant of concern no longer in circulation.
Names
The variant is also known as the South African variant.
Mutations
There are three mutations of particular interest in the spike region of the lineage B.1.351 genome: K417N E484K N501Y and a further five spike mutations which have so far generated less concern: L18F D80A D215G R246I A701V Away from the spike region, it also carries: K1655N, SGF 3675-3677 deletion, P71L, and T205I.
Scientists noted that the variant is able to attach more easily to human cells because of three mutations in the receptor-binding domain (RBD) in the spike glycoprotein of the virus: N501Y (a change from asparagine (N) to tyrosine (Y) in amino-acid position 501), K417N, and E484K. Two of these mutations, E484K and N501Y, are within the receptor-binding motif (RBM) of the receptor-binding domain (RBD).
The N501Y mutation has also been detected in the United Kingdom. Two mutations found in the Beta variant, E484K and K417N, are not found in Alpha variant. Also, Beta does not have the 69-70del mutation found in the other variant.
Vaccine efficacy
On 4 January 2021, UK newspaper The Telegraph reported that Oxford immunologist Sir John Bell believed there was "a big question mark" over the new South African variant's potential resistance to COVID-19 vaccines, raising fears that vaccines might not work as effectively on that variant strain. The same day Shabir Madhi, professor of vaccinology at the University of the Witwatersrand, commented to CBS News that "it's not a given" that the new Beta variant (501.V2 variant) would be able to evade the vaccines, but that it should be considered that they "might not have the full efficacy". The additional mutations to the spike protein in Beta were raised as a concerning factor by Simon Clarke, an associate professor in cellular microbiology at the University of Reading, in that they "may make the virus less susceptible to the immune response triggered by the vaccines". Lawrence Young, a virologist at Warwick University, also noted that the variant's multiple spike mutations "could lead to some escape from immune protection".
The E484K amino acid change, a receptor-binding-domain (RBD) mutation, was reported to be "associated with escape from neutralising antibodies" which could adversely affect the efficacy of spike protein-dependent COVID vaccines. The E484K spike mutation was linked to a case of reinfection with the Beta variant of SARS-CoV-2 in Brazil, believed by researchers to be the first such case of reinfection involving this mutation. The possibility of an alteration in antigenicity was referred to as an "escape mutation" from a monoclonal antibody with the capability of neutralizing the spike protein variants of SARS-CoV-2. This suggests that existing vaccines can and should be updated to counter the new strains without recourse to phased trials.
Janssen
In January, Johnson & Johnson, which held trials for its Janssen (Ad26.COV2.S) vaccine in South Africa, reported the level of protection against moderate to severe COVID-19 infection was 72% in the United States, but 64% in South Africa.
Pfizer–BioNTech
On 17 February 2021, Pfizer announced that neutralisation activity was reduced by two thirds for the Beta variant, whilst refraining from making claims about the efficacy of the vaccine in preventing illness as a result of this variant.
On 16 March 2021, The South African Health Products Regulatory Authority (SAHPRA) approved the Pfizer-BioNTech vaccine (BNT162b2) for section 21 Emergency Use Authorisation.