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It has not been a good news day when it comes to vaccines—particularly AstraZeneca—and the B.1.351 variant that arose in South Africa.
But buried amidst the bad news of a halted rollout there was a paper suggestive of very good news released: this one. https://www.biorxiv.org/content/10.1101/2021.02.05.430003v1
But buried amidst the bad news of a halted rollout there was a paper suggestive of very good news released: this one. https://www.biorxiv.org/content/10.1101/2021.02.05.430003v1
What did they do?
They built synthetic (pseudotyped— https://en.wikipedia.org/wiki/Pseudotyping) virions that express the spike protein from various SARS-CoV-2 strains including B.1.1.7 and B.1.351, and looked at where serum from natural infection and from the Pfizer vaccine can neutralize these.
They built synthetic (pseudotyped— https://en.wikipedia.org/wiki/Pseudotyping) virions that express the spike protein from various SARS-CoV-2 strains including B.1.1.7 and B.1.351, and looked at where serum from natural infection and from the Pfizer vaccine can neutralize these.
Because these are not direct studies of clinical outcomes in actual patients infected with SARS-CoV-2 itself, they are merely suggestive about the effectiveness of natural immunity and of the Pfizer vaccine.
But I think they are strongly suggestive.
But I think they are strongly suggestive.
What did they find?
Serum from patients who contracted COVID before the B.1.1.7 and B.1.351 variants started to spread remains effective at neutralizing virus with the spike protein from these variants, and does almost as well against them as against the previous strain. Good.
Serum from patients who contracted COVID before the B.1.1.7 and B.1.351 variants started to spread remains effective at neutralizing virus with the spike protein from these variants, and does almost as well against them as against the previous strain. Good.
Serum from patients who were vaccinated with the Pfizer vaccine is fantastic against the previous strain, and while somewhat less effective against the new strains, is still better even than natural immunity—which was pretty darn good to start with. Great.
What does it mean?
It means that we can be optimistic that the Pfizer vaccine (and presumably Moderna as well) will continue to offer protection against B.1.351 and B.1.1.7.
It means that we can be optimistic that the Pfizer vaccine (and presumably Moderna as well) will continue to offer protection against B.1.351 and B.1.1.7.
Still, the decline in neutralizing activity against B.1.351 suggests that we should start looking at a vaccine or booster that includes the E484K mutation that we think is responsible for this reduction.
