A huge amount of discussion and speculation is surrounding the newly detected variants of COVID-19 and whether they might affect the efficacy of the vaccines. There’s still much more work to be done before we have any solid answers, but here’s what we know so far.
The past month has seen concerns regarding newly identified variants of the SARS-CoV-2, the virus that causes COVID-19. Some of the most worrying “variants of concern” have undergone mutations that affect the spike protein found on the outer shell of the virus.
One of the most prominent mutations, known as N501Y mutation, has been found to affect the spike protein in the “UK variant.” Meanwhile, the “South African variant” and the “Brazil variant” contain the N501Y mutation along with other mutations to the spike protein, such as E484K. Since this spike protein is used by the virus to enter human cells and is targeted by most of the vaccines, it’s been speculated that the variants may reduce the efficacy of the vaccines.
Studies are starting to look into this question. One recent paper, which has not yet been peer-reviewed, assured that the “UK variant” with its N501Y mutation is still fully susceptible to antibodies made in response to the Pfizer/BioNTech vaccine. While this is certainly good news, the UK variant is thought to be less problematic as it only features one key mutation to the spike protein, while other variants of concern such as the “South African variant” and the “Brazil variant,” feature multiple mutations.
Another paper released this week, which has also not yet been peer-reviewed, suggests that antibodies gained from either the Moderna or Pfizer/BioNTech vaccine weren’t as effective against variants with many of the key mutations, including both the N501Y and E484K mutation. It concludes: “activity against SARS-CoV-2 variants encoding E484K or N501Y... was reduced by a small but significant margin.”
However, it’s worth noting that the variants in this study didn’t totally “escape” the vaccine and it still provided some protection. Vaccines can spark quite a broad response to the infection and immune responses are simply black and white. While some variants might make the job harder, they can still provide some protection.
"I think that all currently licensed vaccines will remain highly effective against current variants of SARS-CoV-2, though those variants with the E484K mutation (Brazil and South African, but not the UK) may be less effective, but probably not to a degree that would undermine the current vaccination program," Professor Paul R Hunter, from the Norwich School of Medicine at the University of East Anglia, told IFLScience.
"In general, coronaviruses have high fidelity of replication and so we are unlikely to see major escapes from vaccine immunity in a single jump, but over time there may be some drift away from vaccine-induced or natural immune protection," they added.
Furthermore, clinical trials have shown that most of the licensed COVID-19 vaccines are highly effective — more effective than flu vaccines — which could give them some leeway when faced with variants.
“The efficacy of the vaccine is so good and so high that we have a little bit of a cushion,” Rochelle Walensky, the new director of the US Centers for Disease Control and Prevention for the Biden administration, said in an interview this week with JAMA.
In all likelihood, future COVID-19 vaccines will have to be modified to cope with these variants. This might sound like a far-out idea, but the production of new flu vaccines each season shows that it can remain an effective way to curb the disease.
For more information about COVID-19, check out the IFLScience COVID-19 hub where you can follow the current state of the pandemic, the progress of vaccine development, and further insights into the disease.