It remains unclear whether the reduction in the neutralization sensitivity of the N501Y.V2 strain to vaccine-induced antibodies is enough to seriously reduce vaccine efficacy. First, mRNA vaccines also induce virus-specific helper T cells and cytotoxic T cells, both of which might be involved in protection against challenge. Also, the mRNA vaccines, in particular, induce such a strong NAb response that there could be enough “spare capacity” to deal with reductions in the sensitivity of the variant to NAbs. In other words, N501Y.V2 (and the related virus from Brazil) may be less sensitive to NAbs, but not to an extent that will cause widespread vaccine failure.