> The documents published in The Lancet confirm that the error lay with the Oxford researchers. A common emulsifier, polysorbate 80, used in vaccines to facilitate mixing, had interfered with the ultraviolet-light meter that measures the quantity of viral material, according to the documents. As a result, the vaccine’s viral concentration was overstated and Oxford ended up administering half doses of vaccine, believing they were full doses.
To recap, you need a way to know the vaccine concentration so that you can draw the correct amount from the vial when dosing patients. Oxford was using a technique called UV spectroscopy. Place a sample of liquid in a UV light beam with a source on one end and a detector on the other. The relationship between absorbance and concentration is linear. BUT: you have no idea what's absorbing the light - only that it's happening. If other materials that absorb at the same UV wavelengths are present, you'll think the concentration of what you're measuring was higher than it actually was.
According to the article, Polysorbate 80 (an "emulsifier" used to stabilize the vaccine) and the virus absorb at the same wavelength being used to quantitate the virus.
Someone, somewhere forgot to do take the absorbance of UV light by Polysorbate 80 into account. This led to overestimation of the concentration of virus present in the batch received from the manufacturer by 2x. This 2x too high concentration was then mistakenly used in the study to determine the volume of vaccine to administer to patients. The patents only got half of the dose they should have.
This is a fundamental error that no experienced chemist would ever make. If all of this is correct, I would immediately start thinking about other fundamental errors that may have occurred in the study.
To recap, you need a way to know the vaccine concentration so that you can draw the correct amount from the vial when dosing patients. Oxford was using a technique called UV spectroscopy. Place a sample of liquid in a UV light beam with a source on one end and a detector on the other. The relationship between absorbance and concentration is linear. BUT: you have no idea what's absorbing the light - only that it's happening. If other materials that absorb at the same UV wavelengths are present, you'll think the concentration of what you're measuring was higher than it actually was.
According to the article, Polysorbate 80 (an "emulsifier" used to stabilize the vaccine) and the virus absorb at the same wavelength being used to quantitate the virus.
Someone, somewhere forgot to do take the absorbance of UV light by Polysorbate 80 into account. This led to overestimation of the concentration of virus present in the batch received from the manufacturer by 2x. This 2x too high concentration was then mistakenly used in the study to determine the volume of vaccine to administer to patients. The patents only got half of the dose they should have.
This is a fundamental error that no experienced chemist would ever make. If all of this is correct, I would immediately start thinking about other fundamental errors that may have occurred in the study.