There is a lot of concern going around regarding some SARS-CoV-2 variants and the effects they will have on vaccine efficacy. You or people you know might ask things like, “If the vaccines won’t work anymore, why even bother getting vaccinated?” This is a misinformed take on the situation.
Given what we know right now (02–28–2021), I’m not concerned about the existing viral variants with regard to their impacts on the mRNA vaccines that are currently available in the US, and I don’t think most of the public should be concerned either. Media outlets might intentionally or unintentionally freak people out by claiming that the vaccines are “6–8x less effective against a new variant” usually referencing the B.1.351 variant that was originally identified in South Africa. While this is KIND OF true, it lacks important context that, in my opinion, make it less problematic. Some data below helps demonstrate what I mean.
The figure has three graphs from two pieces that were published last week in “The New England Journal of Medicine” (citations below). The first 2 graphs reference the Moderna vaccine and the final graph references the Pfizer/BioNTech vaccine. Both studies compared the ability of the serum antibodies from immunized people to neutralize viruses with the spike protein of viruses that were circulating early in the pandemic and the spike protein of the newly emerged B.1.1.7 UK variant or B.1.351 South African variant.
The first graph shows that, for the Moderna vaccine, neutralization is similar between the old D614G and new B.1.1.7 variant. Good news for sure, since the B.1.1.7 UK variant seems to spread easier than other variants and be associated with higher mortality.
In contrast, it’s clear in the 2nd and 3rd graphs that antibodies from vaccinated individuals are less able to neutralize the virus with the B.1.351 South African spike proteins. This is where the “6x-8x less effective” comes from in the media.
But here’s the thing, THESE ANTIBODIES STILL NEUTRALIZED THE VIRUSES! Even with a reduction in antibody effectiveness, this does not translate in a 1-to-1 fashion with actual immune protection. This is because circulating antibodies are only 1 part of the adaptive immune response. Other critically important cells, known as T cells, recognize pathogens in ways that are distinct from the way antibodies and B cells do. Ultimately these T cells recognize different parts of the virus, and mutations that lead to escaping antibodies likely won’t impair T cells. In a situation where antibodies lose all effectiveness (this hasn’t happened yet), infection may occur, but T cells can come in and rapidly clean up the mess by identifying infected cells and killing them, or helping new B cells to develop that produce new antibodies. Symptomatic infection might result, but rapid responding T cells can help prevent severe disease.
At the moment, the worst-case scenario is that, for a few select variants, protection against symptomatic COVID is somewhat reduced. However, data coming out of South Africa for a few trials suggests that protection against severe disease, hospitalization, and death are still high even when the B.1.351 variant is dominant. This data still needs to be more public but ultimately this is good news. Despite the new variants, the vaccines we have available should still offer protection and particularly protect against the worst the virus can offer. This is the end goal, and this is still how we truly get back to normal. Don’t let fear-mongering news stories prevent you from getting vaccinated if you’re eligible.
“Serum Neutralizing Activity Elicited by mRNA-1273 Vaccine — Preliminary Report
“Neutralizing Activity of BNT162b2-Elicited Serum -Preliminary Report