Thread by @1foreverseeking

😳"licensed vaccine has same formulation as EUA-authorized vaccine & can be used interchangeably to provide vaccination series w/o presenting any safety or effectiveness concerns".

"products are legally distinct w/ certain differences that do not impact safety or effectiveness."

Legally distinct.
Have certain differences.
What differences?
fda.gov/media/150386/d…

1 dose (0.3 mL) contains 30 micrograms of COVID-19 mRNA Vaccine (embedded in lipid nanoparticles).
Single-stranded, 5’-capped messenger RNA (mRNA) produced using a cell-free in vitro transcription
from corresponding DNA templates, encoding viral spike (S) protein of SARS-CoV-2.

ema.europa.eu/en/documents/p…

Each 0.3 mL dose of Pfizer-BioNTech COVID-19 Vaccine contains 30 mcg of a nucleosidemodified messenger RNA (modRNA) encoding the viral spike (S) glycoprotein of SARS-CoV-2.

Each dose of Pfizer-BioNTech COVID-19 Vaccine also includes following ingredients:
fda.gov/media/150386/d…

EUA
Nucleosidemodified messenger RNA(modRNA) encoding viral spike(S) glycoprotein of SARS-CoV-2

Comirnaty
Single-stranded 5’-capped messenger RNA(mRNA) produced using cell-free in vitro transcription from corresponding DNA templates encoding viral spike(S) protein of SARS-CoV-2

ModRNA!
Synthetic and chemically modified messenger RNA!

ModRNA -Produced using cell-free in vitro transcription from corresponding DNA template...man-made short-lived heterologous 5′-capped messenger RNA (mRNA) in which some nucleosides replaced by other non-standard naturally modified in eukaryotes or by synthetic nucleoside analogs

modRNA: DISADVANTAGES & UNCERTAINTIES
Achilles heel...appears to be hypersensitivity ... Because mRNA is rapidly & easily degradable by ribonucleases showing half-life w/o delivery system around 7 h, to achieve transfection it must be incorpored into PEGylated lipid nanoparticles

PEGylation is chemical process of both covalent & noncovalent attachment of polyethylene glycol (PEG) polymers to macromolecules, such as therapeutic vesicles, to favor tissue delivery. PEG ...often found as excipient inside everyday products...medicines, cosmetics, or foods.

Increased # allergic reactions to PEG-containing drugs or personal hygiene consumables reported...reasonable to assume... PEGylated nanoparticles may trigger type I (immediate, anaphylactic) hypersensitivity reactions observed for other PEG meds in form of systemic reactogenicity

Types of hypersensitivity reaction according to modern Gell & Coombs's classification... type II (cytotoxic-antibody-dependent) type III (immune complex) type IV (delayed,antibody-independent) & type V (autoimmune) should be considered in short & long term after modRNA vac

or any COVID-19 vaccine. In fact, some autoimmune diseases occur after an exogenous antigenic stimulus in genetically predisposed subjects.

Additional issues arise...impact of new SARS-CoV-2 circulating variants on vaccine-induced protection & on antibody-dependent enhancement, an immunological escape mechanism already exploited by other RNA viruses, such as dengue virus, Ebola virus & HIV.

onlinelibrary.wiley.com/doi/10.1002/jm…

@threadreaderapp
unroll please