Tuesday, August 10, 2021

Why Vaccines Won't Provide Herd Immunity Against COVID-19 Variants

Here is an absolutely fascinating video taken from this tweet from the Twitter account of Channel 4 News in the United Kingdom:



Professor Sir Andrew Pollard is the Director of the Oxford Vaccine Group and is the Lead Investigator of the Oxford University's trials of the AstraZeneca COVID-19 vaccine as shown here:


....and here where he discusses the Oxford-AstraZeneca COVID-19 vaccine:



Here is a transcript of his comments made to the U.K.'s All-Party Parliamentary Group on the Coronavirus as noted in the video above with all bolds being mine:


"I think we are in a situation with this current variant where herd immunity is not a possibility because it still infects vaccinated individuals.  And I suspect what the virus will throw up next is a variant which is perhaps even better at transmitting in vaccinated populations.  And so that's an even more of a reason not to be making a vaccine programme around herd immunity.  I don't think that there's anything the UK can do to stop the emergence of new variants, they're going to happen.  And, if anything, we need to focus now not on what might stop new variants, because I don't think we have any facility to control that.  We need to focus on thinking about how do we prevent people dying going to hospital.  And, I think this is an enormously important thing to be thinking about today because during the course of this week there will be about 65,000 deaths in the world.  We have now over four billion doses deployed of the vaccine globally and that is now enough doses to have prevent almost all of those deaths and yet they are climbing.  So, when you think about what the UK strategy should be around variants, I don't think there's anything that we can do.  But what we can do is play a more active role in the global imperative which is to stop people dying.  That means making sure the doses are going to the right people."

I'm assuming by his comments that "herd immunity is not a possibility" refers to herd immunity provided by vaccination.


Basic evolutionary science tells us that Pollard's comments about the virus throwing up new variants that are even better at being transmitted is quite likely since viruses evolve or adapt to ensure their survivability.  This seems to be holding true during the current pandemic; anecdotally, at this time, it appears that the Delta variant made its appearance after the vaccine rollout began and continues to evade the vaccines that were designed to combat the original iteration of the SARS-CoV-2 virus.  While the science on this is not yet complete, initial research would seem to bear that out as shown here:


...and here:


Interestingly, Andrew Noymer, an epidemiologist at the University of California at Irvine stated this in a British Medical Journal article entitled "COVID-19: Delta infections threaten herd immunity vaccine strategy":

"If the vaccinated can become infected and, we believe from other studies, potentially spread covid, then herd immunity becomes more mirage than oasis."

As well, Public Health England has recently announced another Variant Under Investigation effective July 21, 2021 which it terms VUI-21JUL-01 aka B.1.621.  PHE claims that there is:

"...preliminary laboratory evidence to suggest that vaccination and previous infection may be less effective at preventing infection with VUI-21JUL-01. However, this data is very limited and more research is required. There is no evidence to suggest that VUI-21JUL-01 is more transmissible than the dominant Delta variant.

This new variant is not more transmissible than Delta....at least for now.

Only time and a great deal of additional research will tell whether the appearance of new and more transmissible variants will occur as the vaccine rollouts continue and whether Professor Sir Andrew Pollard's suggestion that governments focus on the prevention of deaths among the vulnerable (i.e. the elderly and those with pre-existing conditions) is actually heeded as it should have been all along.

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