I dunno if you guys know how good we have it today with vaccines.
Let me try this analogy– Lets say you want to bake some bread. You have a basic recipe, so you know you need flour, yeast, water, and you make some really basic bread. Except the bread that comes out of the oven is a loaf of cinnamon raisin walnut bread. So, youre happy, cause you got bread, and its good, but you dont know how the hell the cinnamon/raisins/walnuts got in there.
Thats kinda how old-school vaccines worked. Scientist made a vaccine, it worked, yay!… but there was other stuff in that end batch they didnt know was there cause they didnt know they added it and they didnt know to look for it, or they plain ol didnt know such things existed.
Does that make any sense? Just a long way of saying “In the olden days, vaccines could get a bit messy.”
With the technology we have at our disposal today, this isnt really an issue anymore. Not only do we have lots of lovely ways of killing wayward things that might sneak into a vaccine, but we have lots of neat technology for monitoring our vaccines for little buggars that still try to sneak through.
Viral nucleic acids in live-attenuated vaccines: detection of minority variants and an adventitious virus.
- Trivalent oral poliovirus (OPV)
- Rubella (Meruvax-II)
- Measles (Attenuvax)
- Yellow fever (YF-Vax)
- Varicella-Zoster (Varivax)
- Multivalent Measles/Mumps/Rubella (MMR-II)
- Two rotavirus live vaccines (Rotarix and Rotateq)
So if there is any super-scary contaminant in these usual vaccines, these folks were gonna find it!
And they basically found jack squat.
Attenuvax had a tiny bit of ALV in it, but ALV cant infect humans. MMRII and YF-Vax had ALV too, but they had to use super crazy sensitive PCR to kinda-sorta see it. So it appears ALV is going to be in any vaccine we make from chicken embryos… but again, doesnt exactly matter because it cant infect us.
Rotateq had a teeeeeny teeeeny tiny amount of SRV in it, but its non-functional DNA (its from an ERV in the cell line used to grow the vaccine). They also found some in Rotarix (with super crazy sensitive PCR), implying that like the chicken embryos and ALV, SRV is going to be in any vaccine that uses the Vero cell line at some level… but they couldnt find it anywhere in the Oral Polio Vaccine, which also uses the Vero cell line. Yay!
Rotarix had a lot, actually, of PCV1… PCV1 is harmless (in pigs and humans), but like, there was (relatively) a lot of it, so these folks investigated further. They checked the other rotavirus vaccine (Rotateq), but didnt have any PCV1, even with super crazy sensitive PCR. So, these scientists were concerned Glaxo (maker of Rotarix) had an industry-wide contaminant going, so they checked another vaccine from Glaxo, Pediarix, that contains “diphtheria, tetanus, pertussis bacteria, hepatitis B and killed polioviruses.” It didnt have any PCV1.
It turns out PCV1 is in the ‘seed’ cells Glaxo uses to make Rotarix. Even though PCV1 is harmless, I mean, its like ant legs in your canned pears. You know theyre there. Its harmless. You dont really ever think about it until someone says to you “Did you know the FDA allows manufacturers to have like 6 ant legs per can?” But if there were a way to make sure there was never ant legs in your canned pears, itd be nice. So Glaxo pulled their current stock of the vax, and is remaking it, minus PCV1.
There are no scary crazy IZ A GUNNA KILLZ MAH BABBY stuff in our vaccines! Yay!!