Monday, March 22, 2021


By Lily Hikam*)

Let me start with a rather perplexed statement. When I read the MUI reports on findings on the use of trypsin of porcine origins in the AstraZeneca COVID-19 vaccine, I admit there is some *confusion* on my part when the MUI insisted that the vaccine contained porcine trypsin while AstraZeneca affirmed that their vaccine contained “no material of human or animal origin are used in the growth medium or feed (including no materials manufactured with animal-derived material)” (COVID-19 Vaccine Astra Zeneca Public Assessment Report, pg. 17.)

So, I went and did some research of my own. I read the COVID-19 Vaccine Astra Zeneca Public Assessment Report (1) submitted to the European Medicines Agency (EMA), which is also one of the documents referenced by the MUI in its own report. Unfortunately I couldn’t find the WHO dossier that was sent to BPOM (also referenced in the MUI report). Curiously, I found no reference and no mention of “trypsin”, “porcine trypsin” or any of the tables the MUI report referenced in the document submitted to EMA (Table 2 and Table 3).

However, I did find a reference to how the vaccine was made and “separated from the host”. AstraZeneca claimed that the harvesting process (page 16) involves a detergent-based cell lysis, which is just a fancy way of saying harvesting the cell’s contents by destroying the cell membrane, then treating with nucleases (enzymes that degrade the host cell’s DNA, but not the DNA that will be used as the vaccine) then clarified using depth filtration and then downstream processes to further purify and concentrate the vaccine. Trypsin *was not mentioned at all.* Perhaps because the harvest process described previously negates the use of trypsin that is usually needed to detach cells from the petri dish. And if trypsin was used at all, it is in the process of passaging and maintaining the cell line they used to produce the virus seed.

Next, I looked up the use of T-REx™-293 Cell Line, which is the cell line used to produce this recombinant virus (2). This virus is a genetically modified version of a cell line that we use often in laboratories to produce proteins or expression vectors due to its efficiency in producing them. This T-REx™-293 cell line is propagated using normal culture media and under normal culture conditions. One of the necessary items to maintain this culture is Trypsin, required to detach cells from the petri dish if the researcher wants to move the cells to a bigger dish or do some experiments on the cells. On the manufacturer’s protocol, Trypsin EDTA was listed as “Required item not supplied”. But they wrote it as “Trypsin EDTA or other trypsin solution”, which means the user would have freedom of choice as to which type of Trypsin they utilize for this process. The screenshot provided by MUI’s report is of the “Related Materials” at the end of the product manual which only listed Trypsin-EDTA. *This seems misleading* to me as it gives the impression that this cell line can only be maintained using Trypsin-EDTA, while in reality Trypsin-EDTA or other trypsin solution would suffice.

Biologics nowadays are required to be manufactured in accordance to current good manufacturing practices (cGMP). One of the tenets of cGMP is that materials that are destined for use in the human body (i.e drugs, vaccines, saline solution, vitamins) need to be sterile and free of animal components (xeno-free) or components derived from another species to avoid any adverse reactions by the immune system. As such, there have been many xeno-free reagents or synthetic reagents that have been developed to support this cGMP requirement to replace the conventional use of animal-derived reagents and enzymes. Reagents with animal components in them are usually only used during the research stage (because they’re cheaper) and would not be used during any of the manufacturing process. Even someone like me, who is a novice drug developer, know to avoid any reagents that have animal components during the development process, so I’m quite sure that a multibillion dollar company like AstraZeneca would know better than to use regular Trypsin.

Drawing from the evidence gleaned so far, I remain *unconvinced by MUI’s claims that trypsin of a porcine origin was used in the manufacturing process.* Perhaps more data will be forthcoming in the upcoming days, but for now I remain unconvinced as I’m unable to verify MUI’s assertion using the submitted dossier to the EMA.

*) PhD in Biochemistry, University of California at Irvine (UCI).








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