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Flublok: which risks did reviewers probe?

influenza vaccine, recombinant hemagglutinin · Influenza HA
Immune & cytokine safety
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Biodistribution & persistence
Not conducted; pharmacokinetic studies not required for vaccines
“In accordance with current guidelines, pharmacokinetic studies are not required for the vaccine assessment. No non-clinical pharmacokinetic studies have been performed to evaluate absorption, distribution, metabolism and excretion of the active ingredients of RIV4.”
✓ VerifiedEMA assessment report, p. 27Source ↗
Modality-specific risk
Local tolerance: transient injection-site inflammation after IM injection only
“Transient microscopic inflammation at injection sites was observed after IM injection only, which was expected.”
✓ VerifiedEMA assessment report, p. 29Source ↗
Anti-drug antibodies: animals
All vaccinated rat dams mounted antibodies to the three strains; maternal antibodies reached fetuses and pups
“RIV3 at the human dose induced an active immune response to the three strains in all rat dams from the vaccine group. The exposure of foetuses and pups to vaccine-specific maternal antibodies was also demonstrated.”
✓ VerifiedEMA assessment report, p. 29Source ↗
Anti-drug antibodies: patients
One IM dose immunogenic (HAI) for each vaccine strain in adults 50 years and older
“Overall, one 0.5 mL IM dose of RIV4 is demonstrated immunogenic for each vaccine strain in subjects ≥50 years of age”
✓ VerifiedEMA assessment report, p. 92Source ↗

Same question, other vaccines

Arexvy

respiratory syncytial virus vaccine, adjuvanted (AS01E) · RSV preF3; TLR4 (AS01E adjuvant)
In mice, AS01-adjuvanted RSVPreF3 induced CD4+/CD8+ T cells, neutralising antibodies and proinflammatory cytokines

Cervarix

human papillomavirus bivalent (types 16, 18) vaccine, recombinant, AS04-adjuvanted · HPV 16/18 L1 VLPs; TLR4 (AS04 adjuvant)
No neurological, immunological or autoimmune adverse reactions in MPL-containing preclinical studies (FDA concurred)

Cyfendus

anthrax vaccine adsorbed, adjuvanted · B. anthracis PA; TLR9 (CpG 7909 adjuvant)
Transient neutrophil, monocyte, basophil and inflammatory-marker increases; spleen weight increase and lymphoid hyperplasia

Fendrix

hepatitis B vaccine (rDNA), AS04C-adjuvanted · HBsAg VLPs; TLR4 (AS04C adjuvant)
Anti-HBs seroconversion in rabbits; rat dams and offspring exposed to high anti-HBs titres

Gardasil

human papillomavirus quadrivalent (types 6, 11, 16, 18) vaccine, recombinant · HPV 6/11/16/18 L1 VLPs
Theoretical autoimmunity from cross-reactive antibodies, not readily studied in animals; left to clinical assessment

Gardasil 9

human papillomavirus 9-valent vaccine, recombinant · HPV 9-valent L1 VLPs
Transient spleen weight increase from immune stimulation; theoretical autoimmunity risk left to post-marketing

HBVaxPro

hepatitis B vaccine (rDNA) · HBsAg VLPs
No autoimmune reactions, kidney or vascular lesions, or immune complex deposition in the rat repeat-dose study

Heplisav-B

hepatitis B vaccine (recombinant), adjuvanted · HBsAg; TLR9 (CpG 1018 adjuvant)
Serum IL-12p40 rose only 2-fold at ~20x the human CpG 1018 dose; no IL-12p40 or IFN-gamma increase at the 1x human dose

Mosquirix

RTS,S/AS01 malaria vaccine · P. falciparum CSP-HBsAg (RTS,S) VLPs; TLR4 (AS01 adjuvant)
Transient neutrophil and fibrinogen increases after dosing, back to pre-dose levels within three days

Nuvaxovid

COVID-19 vaccine, recombinant spike protein nanoparticle, Matrix-M-adjuvanted · SARS-CoV-2 spike (nanoparticle)
Matrix-M1: injection-site inflammation, reversible draining lymph node enlargement, raised CRP, fibrinogen and globulin (immune stimulation)

PreHevbrio

hepatitis B vaccine (recombinant), 3-antigen · HBsAg S/pre-S1/pre-S2 VLPs
Slight lymphoid hyperplasia in spleen and lymph nodes, an expected immunostimulatory effect

Shingrix

zoster vaccine recombinant, AS01B-adjuvanted · VZV glycoprotein E; TLR4 (AS01B adjuvant)
Acute-phase response (CRP rise) indicating systemic inflammation, possibly linked to malaise, fatigue and nausea

Summary across all 13 vaccines →