BOC Sciences Provides Adjuvants to Assist Vaccine Development

Recently, BOC Sciences, a well-known pharmaceutical raw material supplier, announced to provide customers with adjuvants to assist the development of new vaccines during the COVID-19 pandemic.

Adjuvant refers to a substance that is injected into the animal before the antigen or mixed with the antigen, which can non-specifically change or enhance the specific immune response of the body to the antigen, and is not immunogenic and cannot cause an immune response. The role of adjuvants in immunity is mainly to enhance the immune response of the body's immune system (humoral or cellular immune system) to antigens or immunogens, including enhancing the strength and durability of the immune response. According to usage, adjuvants can be divided into experimental adjuvants and vaccine adjuvants. The experimental adjuvants are mainly used for the preparation of specific antibodies, while the vaccine adjuvants are used as essential components of the vaccine.

Common adjuvants include aluminum salt adjuvant, Freund's adjuvant, microbial and metabolite adjuvant, liposome adjuvant, immune stimulation complex (ISCOM), cytokines and so on.

1. Aluminum salt adjuvant

Aluminum salt adjuvant is a kind of inorganic salt containing Al3+, mainly including aluminum hydroxide glue, aluminum phosphate and alum. Aluminum salt adjuvant has a history of more than 70 years of application, and it is the only adjuvant that can be used by humans and animals approved by the FDA. The main function of aluminum salt adjuvant is sustained release, but at the same time it has the effect of activating immune cells. The mixed injection of protein and aluminum hydroxide or aluminum phosphate can keep the antigen at the injection site, that is, the "storage effect", which has the effect of antigen slow release and non-specific immune stimulation. Approved aluminum-containing adjuvant vaccines include DTP, cell-free pertussis vaccine DTP (DTaP), influenza B (HIB) vaccine (not all), hepatitis B (HB) vaccine, and all DTaP, HIB or HB Of the combined vaccines, hepatitis A vaccine, Lyme disease vaccine, anthrax vaccine and rabies vaccine.

1. Freund's adjuvant

Freund's adjuvant (FA) is one of oil emulsion adjuvants and is the most widely used experimental adjuvant. Its main feature is that it has a strong immune enhancement effect. Freund's adjuvant (FA) includes Freund's complete adjuvant (FCA) and Freund's incomplete adjuvant (FIA). FIA contains low-viscosity mineral oil and emulsifier, and FCA contains inactivated Mycobacterium tuberculosis in addition to the above ingredients, which has a strong activation effect on humoral and cellular immune systems.

1. Microbial and metabolite adjuvant

3.1 Lipopolysaccharide (LPS)

LPS activates T cells and B cells, has an adjuvant effect on both humoral immunity and cellular immunity, and can improve the immune response of proteins to polysaccharide antigens. The main component of the LPS that shows an adjuvant effect is lipid A. Under acidic conditions, lipid A can be hydrolyzed to obtain monophospholipid A (MPL). MPL maintains lipid A's adjuvant activity and reduces toxic effects. As a Th1-type adjuvant, MPL has shown acceptable safety in human and animal studies. At present, MPL has been used in some vaccine preparations such as hepatitis B and HSV-II vaccine preparations.

3.2 Mycobacterium and its components

Mycobacterium is widely used in vaccines in veterinary medicine. Mycobacterium can be treated with chemical and physical methods to obtain components with adjuvant activity, including MDP, MTP, waxy D and so on. The active factors of mycobacterial cells are present in the cytoskeleton (CWS). The FCA adjuvant containing CWS can stimulate an increase in the amount of circulating antibodies produced, induce cellular immune formation, and can last for a considerable period of time.

3.3 CpG ODN

CpG ODN refers to oligodeoxyribonucleotides with unmethylated cytosine and guanine nucleotides at the core. CpG sequences can activate immune cells such as T cells, B cells, and NK cells, produce a large number of cytokines, enhance the body's specific and non-specific immune effects, and stimulate mucosal immune responses. Currently, CpG has entered clinical trials as a human hepatitis B vaccine adjuvant.

1. Liposome (LIP)

LIP is a synthetic bilayer monolayer phospholipid or concentric microcircular lipid vesicles separated by multiple layers of soluble substances, which can wrap various substances and vaccines. Liposomes are both antigens and immune adjuvants, which can deliver antigens to immune cells and enhance the body's humoral and cellular immune responses.

1. Immune stimulation complex (ISCOM)

Immune stimulation complex is a highly effective immune adjuvant consisting of protective antigen and microcarriers. ISCOM has the ability to generate a comprehensive immune response and it requires few antigens for effective immunization, making it likely to be an effective adjuvant for multivalent subunit vaccines. At present, a large number of veterinary bacteria, virus and parasite vaccines have been prepared using immunostimulation complex technology, and these vaccines are suitable for various animals such as guinea pigs, pigs, cattle, dogs, rabbits and sheep.

1. Cytokines

Cytokines are cell regulatory proteins with important biological activities, which can protect the body from viruses, bacteria and parasites, and also have a synergistic effect on tumor immunity. For example, interleukin 12 (IL-12) is mainly involved in the body's cellular immune response in the body. IL-12 induces Th0 cells to differentiate into Th1 cells, and at the same time activates the killing function of NK cells and stimulates the secretion of IFN-γ, so it has important Immune regulation and anti-tumor effect.

For more information about the vaccine adjuvants, please visit the website of BOC Sciences: https://www.bocsci.com/products/vaccine-adjuvants-3712.html

About BOC Sciences

With high-profiled experts specialized in multi-disciplines like drug discovery, chemistry and life science, BOC Sciences is a reliable vendor of a comprehensive collection of chemicals for scientists and researchers in both academia and industry. Over the last twenty years, it has gained a fame as well as valuable trust from customers worldwide in the supply of chemicals like small molecule inhibitors, APIs, pharmaceutical excipients, intermediates and natural compounds. In addition, it also provides all-stage-covering drug R&D services to support the pharmaceutical industry.