AS02 - AS03 - AS04
Adjuvant Systems (AS) technologies was first developed by Glasko-Smith-Klein (GSK) in the late 1980s. These are combinations of classical adjuvants – aluminum, oil-in-water emulsions, liposomes, and immunomodulatory molecules.
Four AS Systems Adjuvants have been developed so far.
AS01 is composed of mono-phosphoryl lipid A, otherwise known as MPL, QS-21, and liposomes. AS01 is used to stimulate the innate immune response by binding to Toll-like Receptors (TLR4.)
- 'MPLA is derived from the cell wall of a Salmonella bacteria. It is a very powerful stimulator of the immune system, known to actively bind to and stimulate 'TLR4. In fact, MPL is the first TLR adjuvant approved for use in humans.
- QS21 is extract made from the bark of a South American tree, Quillaja saponaria. It is highly reactogenic and can only be used when combined with other adjuvants. “Toxicity of the food-grade extract from Quillaja saponaria has limited its use as a parenteral adjuvant; however, this toxicity seems to be abated when delivered orally.” Adjuvant patent
- Liposomes are artificial vesicles that have an aqueous core, surrounded by one or more phospholipid layers.
The combination of [MPL + QS-21] is required to achieve the highest antibody response. When any of the particles – MPL, QS-21 or Liposomes – are injected individually, there is little or no antibody response that is seen.
AS02 adjuvant contains MPL and QS-21 in an oil-in-water emulsion. AS02 was used in an experimental malaria vaccine of GSK but as of fall 2018, no vaccine has been approved with this toxic adjuvant.
AS03 adjuvant contains 4.86 mg of polysorbate 80, 10.69 mg of squalene and 11.86 mg of α-tocopherol, a synthetic Vitamin E. It is bound together in phosphate-buffered saline (PBS) as the aqueous carrier.
The α-tocopherol a synthetic form of vitamin E; it is not extracted from plants; it is highly inflammatory. The squalene in AS03 originates from shark liver, the only source of squalene with a high enough level of purity for pharmaceutical applications. AS03 was used in the H5N1 (bird flu) and H1N1 (swine flu) pandemic influenza vaccines. In 2009, the vaccine Pandemrix seemed to increase the risk of narcolepsy in children in Australia and Finland. Narcolepsy is a chronic neurological disorder caused by the brain’s inability to regulate sleep-wake cycles normally. Early studies have downplayed the risk but since that time, Pandemrix was been removed from the market. It was used in early experimental malaria and HIV vaccines, and Pandemrix.
AS04 consists of 50 μg of MLP adsorbed onto 500 μg aluminum hydroxide or aluminum phosphate. The intent of AS04 to induce the production of higher levels of specific antibody, using with fewer injections and smaller use of antigen. AS04 is capable of binding to TLR4 to induce a strong, innate immune response and a VERY strong cytokine response.
AS04 has been evaluated and approved in various vaccines in Europe such as the Hep B vaccine (FED-Drix), and the human papillomavirus vaccine (Cervarix). Other vaccines in undergoing clinical experiments with AS04 include vaccines for herpes simplex, respiratory syncytial virus, and Epstein-Barr. At least 30,000 subjects have been vaccinated with AS04-containing formulations.
September 22, 2016 – A chimeric haemagglutinin-based influenza split virion vaccine adjuvanted with AS03 induces protective stalk-reactive antibodies in mice “Seasonal influenza virus vaccines are generally effective at preventing disease, but need to be well matched to circulating virus strains for maximum benefit. Influenza viruses constantly undergo antigenic changes because of their high mutation rate in the immunodominant haemagglutinin (HA) head domain, which necessitates annual re-formulation and re-vaccination for continuing protection.” Note: See ASO3
May, 2016 – Anaphylaxis Following Immunization of Children and Adolescents in Germany. “Anaphylaxis occurred most frequently following administration of AS03 adjuvanted A/H1N1 pandemic influenza vaccine (n=8). The annual frequency of anaphylaxis after vaccination (excluding pandemic influenza vaccine as well as monovalent measles and rubella vaccines) was estimated to be 6.8 (95% CI: 6.1-10.9). The estimated incidence of anaphylaxis following administration of specific vaccines ranged from 0.4 to 127.6 cases per 1,000,000 doses administered.” Comment: AS03 is being considered for use in a universal influenza vaccine.
January 15, 2015 - Adjuvant system AS02V enhances humoral and cellular immune responses to pneumococcal protein PhtD vaccine in healthy young and older adults: Randomised, controlled trials (full text) "These studies showed that vaccination with the pneumococcal protein PhtD elicits both CD4 T cell and memory B cell responses in adults and that the reduced immune response in older persons compared to young adults can be partially restored with AS02V adjuvant system. The anti-PhtD antibodies elicited post-vaccination were shown to be functional. No safety concerns were raised and AS02V-adjuvanted PhtD had an acceptable reactogenicity profile. An AS02V-adjuvanted PhtD vaccine may therefore be beneficial in efforts to reduce the burden of pneumonia in the adult population, including older persons."..."Conflict of interest: The study was supported by GlaxoSmithKline (GSK) Biologicals"
March 14, 2016 – Comparison of AS03 and Alum on immune responses elicited by A/H3N2 split influenza vaccine in young, mature and aged BALB/c mice “Overall, these effects were most pronounced in the younger animals and the groups receiving AS03. These data support the use of oil-in-water adjuvants in influenza vaccines targeting the elderly.”
April 29, 2014 – Risk factors associated with anaphylaxis and other allergic-like events following receipt of 2009 monovalent AS03-adjuvanted pandemic influenza vaccine in Quebec, Canada “Increased anaphylaxis and other allergic-like events observed in association with AS03-adjuvanted pandemic H1N1 vaccine remain 'mostly unexplained despite extensive risk factor review. However, prior to mass vaccination with similar formulations, this safety signal warrants further consideration and better understanding. In particular, the predominance among women of childbearing age may be a clue to underlying biological or hormonal influences on adverse immunological responses to vaccine.”
July 26, 2013 – Selection of an adjuvant for seasonal influenza vaccine in elderly people: modelling immunogenicity from a randomized trial (full text) “Participants used diary cards to record the occurrence and intensity of injection site solicited adverse events (ecchymosis, pain, redness and swelling) and systemic solicited adverse events (arthralgia, fatigue, headache, myalgia, nausea, shivering and fever) during the first 7 days after vaccination.”…”The reactogenicity profile during the 7 days following vaccination is shown in Figure 7. The percentage of participants reporting at least one local symptom (solicited or unsolicited) ranged from 38.7% to 67.7% in the adjuvanted vaccine groups, 18.0% reported a symptom in the non-adjuvanted ≥65 year group, and 45.8% in the non-adjuvanted 18–40 years group. For systemic symptoms, between 30.9% and 57.1% of participants reported a symptom in the adjuvanted vaccine groups, 25.0% in the non-adjuvanted ≥65year group, and 45.3% in the non-adjuvanted 18–40 years group. The incidence of grade 3 events and fever >40°C was between 0 and 5.0% for all groups. A dose-range effect may be observed on the reactogenicity of the adjuvanted formulations, with a trend towards increasing incidence of symptoms with increasing 'AS03' content and with the presence of MPL. This was also reflected in the solicited symptom profiles.”
July 12, 2013 – Long-term immunogenicity of an AS03-adjuvanted influenza A (H1N1)pdm09 vaccine in young and elderly adults: An observer-blind, randomized trial (full text) “This large-scale, randomized study in subjects ≥18 years of age assessed whether one dose of AS03-adjuvanted HA influenza A (H1N1)pdm09 vaccine-elicited immune response that met the US and European regulatory criteria. Additionally, non-inferiority and superiority of this vaccine's protective efficacy versus a non-adjuvanted HA influenza A (H1N1)pdm09 vaccine were evaluated.”…
”Two of these events, intestinal obstruction (AS03-adjuvanted treatment group) and multiple sclerosis (non-adjuvanted treatment group) were considered by the investigator to be p'ossibly related to study vaccine and were also considered to be potential immune-mediated diseases (pIMDs). Through Day 385 (Month 12), 12 pIMDs according to the predefined list of pIMD preferred terms were reported, with 5 and 7 in AS03-adjuvanted and non-adjuvanted influenza treatment groups, respectively. Seven fatal severe adverse events (SAEs) [7 deaths] were reported, 6 in the AS03-adjuvanted group and 1 in the non-adjuvanted treatment group. All were assessed by investigators as not related to vaccination." Comment: Could the deaths be dismissed due to investigator conflicts of interest?
- All investigators received compensation for study involvement and travel related to this study.
- Ping Li, Miguel Madariaga, Olivier Godeaux and David Vaughn are/were employees of GlaxoSmithKline group of companies and report receiving restricted shares of the company.
- W.Y., M.D., M.K. and N.A. contributed to the data collection, data interpretation and critical review of the manuscript drafts.
- P.L., M.M., O.G. and D.W.V. contributed to the study design, data analysis and interpretation as well as to the critical review of all drafts of the manuscript.
December 29, 2011 – Sanofi H1N1 Influenza Vaccine Administered at Different Dose Levels With and Without AS03 Adjuvant in Healthy Adult and Elderly Populations Study Results – Solicited Subjective Systemic Reactions After the Second Vaccination “Serious Adverse Events: A table of all anticipated and unanticipated serious adverse events, grouped by organ system, with number and frequency of such events in each arm of the clinical trial. (See Adverse Events definition below). Other (Not Including Serious) Adverse Events: A table of anticipated and unanticipated events (not included in the serious adverse event table) that exceed a frequency threshold within an arm of the clinical trial, grouped by organ system, with number and frequency of such events in each arm of the clinical trial.”
September 2011 – Randomized Trial of the Immunogenicity and Safety of the Hepatitis B Vaccine Given in an Accelerated Schedule Coadministered with the Human Papillomavirus Type 16/18 AS04-Adjuvanted Cervical Cancer Vaccine (pdf)
June 10, 2011 – Immunogenicity and safety of AS03-adjuvanted H1N1 pandemic vaccines in children and adolescents “Despite an observed slight increase of the reactogenicity following the second dose in the 3.75 μg HA/AS03A study, the vaccines safety profiles were considered clinically acceptable.”
March 2011 – Adjuvant System AS03 containing α-tocopherol modulates innate immune response and leads to improved adaptive immunity. The presence of α-tocopherol also modulated the expression of some cytokines, including CCL2, CCL3, IL-6, CSF3 and CXCL1; increased the antigen loading in monocytes; and increased the recruitment of granulocytes in the dLNs. Hence, AS03’s promotion of monocytes as the principal antigen-presenting cells, and its effects on granulocytes and cytokines, may all contribute to enhancing the antigen-specific adaptive immune response.”
June 1, 2010 – Safety and Cross-Reactive Immunogenicity of Candidate AS03-Adjuvanted Prepandemic H5N1 Influenza Vaccines: A Randomized Controlled Phase 1/2 Trial in Adults “Adjuvantation was associated with increased short-term injection-site reactions (pain) in 80% of participants, with such reactions assessed as being of grade 3 severity for 4.0% of doses. No other safety or reactogenicity concerns were identified over 6 months of follow-up.”
December 2010 – Monovalent inactivated split-virion AS03-adjuvanted pandemic influenza A (H1N1) vaccine
December 2010 – Delayed focal lipoatrophy after AS03-adjuvanted influenza A (H1N1) 2009 vaccine
October 28, 2010 – Effect on Cellular and Humoral Immune Responses of the AS03 Adjuvant System in an A/H1N1/2009 Influenza Virus Vaccine Administered to Adults during Two Randomized Controlled Trials(full text) “Systemic symptoms tended to occur more frequently in the AS03A-adjuvanted groups, in particular headache (27.0% versus 16.9% in study A, and 38.5% versus 24.2% in study B) and muscle aches (31.7% versus 9.2% in study A and 26.2% versus 9.1% in study B).”
October 2010 – Open-label, randomised, parallel-group, multicentre study to evaluate the safety, tolerability and immunogenicity of an AS03B/oil-in-water emulsion-adjuvanted (AS03B) split-virion versus non-adjuvanted whole-virion H1N1 influenza vaccine in UKchildren 6 months to 12 years of age (pdf) “Among 937 children receiving vaccine, per protocol seroconversion rates were higher after the AS03-adjuvanted vaccine than after the whole-virion vaccine (98.2% vs 80.1% in children < 3 years, 99.1% vs 95.9% among those aged 3–12 years), as were severe local reactions (3.6% vs 0.0% in those under 5 years, and 7.8% vs 1.1% in those aged 5–12 years), irritability in children < 5 years (46.7% vs 32.0%), and muscle pain in older children (28.9% vs 13.2%). The second dose of the adjuvanted vaccine was more reactogenic than the first especially for fever > 38.0°C in those under 5 years of age (8.9% vs 22.4%).”
October 2010 – H1N1 influenza and pandemic flu (pdf 496 pgs) – Summary: Assessment of H1N1 in the UK Health Care System. – Quote on adverse event reporting “Reduce the reliance on trust. Data collecting methodologies (such as adverse events reporting systems) that rely on companies to self evaluate potential harms caused by their drug may lead to bias. Reduce this potential by making mandatory reporting requirement apply to all known adverse events, allowing the importance of a given adverse event to be determined by anybody who cares to analyze the publicly accessible post marketing surveillance database.”
June 1, 2010 – Safety and Cross-Reactive Immunogenicity of Candidate AS03-Adjuvanted Prepandemic H5N1 Influenza Vaccines: A Randomized Controlled Phase 1/2 Trial in Adults (full text) “Overall, the incidence of solicited events was higher in the adjuvanted vaccine groups than in the nonadjuvanted vaccine group, which was significant for pain at the injection site (P<.001), fatigue (P<.001 s), increased body temperature (P=.009), joint pain (P=.016), and muscle aches (P=.001)”
June 2010 – Immunogenicity and safety of AS03-adjuvanted 2009 influenza AH1N1 vaccine in children 6–35 months (pdf) “Spontaneously reported adverse events with an intensity that prevented normal activities were documented for 2.9–6.7% of doses. There was one serious adverse event reported in the AS03A-adjuvanted 3.75 ug HA vaccine group (traumatic brain injury) which was not considered as related to vaccination. In conclusion, these data suggest that a first dose of AS03B-adjuvanted A/H1N1/2009 vaccine containing1.9ug HA in children 6–35months old is highly immunogenic and that the over all reactogenicity profile is acceptable although reactions including fever tend to increase after a second dose.” Comment: The side effects are never due to the vaccines, and any type of reaction is always considered to be acceptable.
April 2010 – Immune mechanisms of protection: can adjuvants rise to the challenge? (full text) “The adjuvant system used in the most successful malarial vaccine is AS02, a preparation that contains both a saponin component and the TLR agonist MPL formulated in a particulate system. Notably, both saponin and MPL were required to induce a modest level of protection in immunized individuals [89]. In contrast, vaccines using the same antigen with aluminum hydroxide and MPL (AS04) or in an oil-in-water emulsion (AS03) induced high levels of antibody but failed to protect against infection.”
2010 – Preclinical development of AS04.
December 2009 – Immunogenicity and tolerability of an AS03A-adjuvanted prepandemic influenza vaccine: A phase III study in a large population of Asian adults
November 4, 2009 – German Medical Association warns: “Swine flu vaccine” unsuitable for patients suffering from environmental diseases and other chronic multi-system illnesses “There exists considerable doubt concerning the safety of the adjuvanted active amplifier since it is being used for the first time. The vaccine contains 27.4mg AS03, an emulsion of polysorbate, squalene and tocopherol. Sufficient studies are lacking, because in the test phase, only the development of antibody titers was determined as a surrogate criterion, and not any potential adverse reactions.”
October 21, 2009 – AREPANRIX™ H1N1 AS03-Adjuvanted H1N1 Pandemic Influenza Vaccine Emulsion for Injection (pdf)
September 1, 2009 – Squalene Emulsions for Parenteral Vaccine and Drug Delivery (pdf) “GlaxoSmithKline Biologicals has developed several squalene emulsion formulations as vaccine adjuvants. SB62 consists of 5% v/v squalene, 5% v/v -tocopherol, and 1.8% v/v Tween® 80 in PBS at pH 6.8, with a particle size of ~150-155 nm.
August 2009 – Prepandemic H5N1 influenza vaccine adjuvanted with AS03: a review of the pre-clinical and clinical data.
November 2008 – A vaccine manufacturer’s approach to address medical needs related to seasonal and pandemic influenza viruses (full text) “In a phase III, randomized safety trial, a 15 μg HA dose of the split-virus H5N1 vaccine adjuvanted with AS03 was compared with the licensed seasonal influenza vaccine Fluarix™ in healthy adults aged 18 years and above.51 Significantly more participants in the AS03-H5N1 vaccine group reported general or local adverse events (84·3% versus 40·2% of subjects 18–60 years and 69·4% versus 34·1% of subjects >60 years, receiving adjuvanted H5N1 antigen and control, respectively).”
January 28, 2008 – Immunogenicity & Safety of GSK’s Influenza Vaccine 1557484A Given to Adults Aged ≥18 Years