The Defender Staff
Vaccine manufacturers set their sights on nasal vaccines at least two decades ago, but so far product development has remained sluggish as scientists acknowledge that only a “thin partition” separates the nasal cavity from the brain.
… Would nasal sprays be more benign than their injectable counterparts? Experience thus far urges caution.
As an otherwise enthusiastic author wrote in 2020, in the journal Mucosal Vaccines, there is little doubt the “inflammatory immune responses” generated by the nose’s encounter with the vaccine antigen “would result in sustained pathologic inflammation.”
Another warning sign comes from testing of mucosal adjuvants (substances added to boost the immune response) in nasal vaccines.
… And the rise of nanoparticulate delivery systems with “yet to be established” safety profiles introduces a range of new questions about toxicity.
One area of concern is the proposed use of the “stealth polymer” polyethylene glycol (PEG) in nasal vaccines.
… PEG-related side effects reported in the literature include hypersensitivity reactions, “unexpected changes in pharmacokinetic behavior” (referring to the processes of “absorption, distribution, metabolism, and excretion”), “toxic side products” and “possible accumulation in the body.”