Results of a recent study on neutralizing capacity of antibodies generated by either mRNA or adenoviral vector-based vaccines against Beta, Delta, Delta plus, and Lambda variants have been investigated by NewYork based researchers.
Since the study was done in the US, the choice was Pfizer-BioNTech, Moderna (both mRNA), and the single-shot Johnson & Johnson (adenovirus) vaccines.
Blood samples collected from those who has received one of these vaccines at several time points, extending from one week to three months post-vaccination. In addition, the neutralizing activity of the generated antibodies towards several SARS-CoV-2 variants was assessed.
Findings:
mRNA vaccines was notably more effective two weeks post-administration against the D614G strain than convalescent sera, with a subsequent and modest 2.5-4.0-fold drop in antibody titer observed towards the SARS-CoV variants of concern in comparison with D614G.
Resistance towards antibodies observed in beta, delta, and lambda variants were attributed to E484K, L452R, and L452Q and F490S mutations, respective to the strain.
L452R/Q mutation of the lambda variant as a key factor in reduced neutralizing antibody potency, seeing a two-fold increase in viral infectivity in immunized hosts and a three-fold increase in relative affinity towards the ACE2 receptor.
Sera from those who received the adenovirus vector-based vaccine was seen to experience an even greater drop in efficacy against the variants of concern compared to the mRNA vaccines, around 5-7 fold against the delta plus or beta variants compared to D614G.
Effects on Regeneron treatments :
Analysis of REGN10933 and REGN10987 monoclonal antibodies that constitute the REGN-COV2 therapy showed that REGN10933 had decreased activity against the Beta variant spike which resulted in a 127-fold decrease in neutralizing titer. REGN10933 also had decreased activity against the Delta plus variant which resulted in a 92.7-fold decrease in neutralizing titer. The resistance to REGN10933 was attributed to K417N and E484K. REGN10933 neutralized virus with the Delta variant spike with a 12-fold decrease in titer which had only a minor effect on the activity of the cocktail. REGN10987 showed a minor reduction in neutralizing titer of virus with the Beta, Delta, Delta plus and Lambda variant spikes but this had little effect on neutralization of the virus by the cocktail. The resistance of variants to REGN10987 was attributed to the L452R/Q.
Since the study was done in the US, the choice was Pfizer-BioNTech, Moderna (both mRNA), and the single-shot Johnson & Johnson (adenovirus) vaccines.
Blood samples collected from those who has received one of these vaccines at several time points, extending from one week to three months post-vaccination. In addition, the neutralizing activity of the generated antibodies towards several SARS-CoV-2 variants was assessed.
Findings:
mRNA vaccines was notably more effective two weeks post-administration against the D614G strain than convalescent sera, with a subsequent and modest 2.5-4.0-fold drop in antibody titer observed towards the SARS-CoV variants of concern in comparison with D614G.
Resistance towards antibodies observed in beta, delta, and lambda variants were attributed to E484K, L452R, and L452Q and F490S mutations, respective to the strain.
L452R/Q mutation of the lambda variant as a key factor in reduced neutralizing antibody potency, seeing a two-fold increase in viral infectivity in immunized hosts and a three-fold increase in relative affinity towards the ACE2 receptor.
Sera from those who received the adenovirus vector-based vaccine was seen to experience an even greater drop in efficacy against the variants of concern compared to the mRNA vaccines, around 5-7 fold against the delta plus or beta variants compared to D614G.
Effects on Regeneron treatments :
Analysis of REGN10933 and REGN10987 monoclonal antibodies that constitute the REGN-COV2 therapy showed that REGN10933 had decreased activity against the Beta variant spike which resulted in a 127-fold decrease in neutralizing titer. REGN10933 also had decreased activity against the Delta plus variant which resulted in a 92.7-fold decrease in neutralizing titer. The resistance to REGN10933 was attributed to K417N and E484K. REGN10933 neutralized virus with the Delta variant spike with a 12-fold decrease in titer which had only a minor effect on the activity of the cocktail. REGN10987 showed a minor reduction in neutralizing titer of virus with the Beta, Delta, Delta plus and Lambda variant spikes but this had little effect on neutralization of the virus by the cocktail. The resistance of variants to REGN10987 was attributed to the L452R/Q.
