When you think about immunization, you might think of the different types of vaccines. For example, there are Live-attenuated vaccines, Toxoid vaccines, Polysaccharide vaccines, and Subunit vaccines. Let’s look at these types and how they work.
Vaccines are made by manipulating bacteria or viruses so that they do not cause disease. Scientists then choose the best type based on the organisms’ natural behavior and how well they can cause a protective immune response. Live-attenuated vaccines are the most effective type of vaccine, and they trigger an immune response in a way that is nearly identical to the natural infection. This is why the reaction to live-attenuated vaccines is stronger than inactivated ones.
Live-attenuated vaccines are weakened versions of live viruses or bacteria. These vaccines induce a strong immune response and provide lifetime protection against diseases. However, you should discuss this vaccination with your healthcare provider if you are at risk of developing an infection before receiving it. Also, you should avoid this vaccine if you have a compromised immune system or have organ transplants. Live-attenuated vaccines must be stored at a cool temperature to be effective. This means that you cannot use them in countries with unavailable fridges.
Subunit vaccines are made with a portion of a pathogen and help induce an immune response to combat the pathogen. Antigens in subunit vaccines may be a polysaccharide or proteins. These subunits are then chemically linked to create a vaccine that produces a long-lasting protective immune response.
There are five types of vaccines. Live attenuated and inactivated vaccines use weakened versions of the germ. Subunit and recombinant vaccines use pieces of the pathogen to cause an immune response but do not cause infection or disease. Polysaccharide and conjugate vaccines use messenger RNA or a portion of the pathogen to stimulate an immune response.
Virus-like particles are another form of the vaccine. These particles closely resemble viruses but contain no viral genetic material. These particles can be naturally occurring or synthesized. VLPs are produced by individual expression of viral structural proteins and can self-assemble into a virus-like structure. VLPs can contain antigens from several pathogens and are more effective than monovalent vaccines.
Toxoid vaccines contain specific parts of germs and produce a strong immune response. They can be given to almost anyone, beneficial for people with weak immune systems or chronic diseases. The vaccines, however, may require booster shots for continued protection. Unlike other immunization methods, toxoids do not multiply in the body and cannot cause disease when administered. They also are highly stable and durable.
Toxoid vaccines can help protect against botulism, tetanus, and diphtheria. These diseases are caused by bacteria that release the toxin into the bloodstream. These vaccines have been purified through different processes to produce a toxoid-specific immune response.
Polysaccharide vaccines contain antigens found on the surface of invasive bacteria. These antigens trigger B-cell responses and, thus, induce protective antibodies. Polysaccharide vaccines are not T-cell-dependent and do not produce long-lasting immunity.
Polysaccharide vaccines are licensed for both children and adults. The vaccines are available in bivalent and quadrivalent formulations. In addition, a trivalent formulation has recently been approved by GlaxoSmithKline Biologicals in collaboration with the WHO and the World Health Organization (WHO). These vaccines are freeze-dried and have a long shelf life when stored between two and eight degrees Celsius.
Polysaccharide vaccines are the oldest type of vaccine, and they are the most common. They contain a combination of proteins and bacterial sugar molecules. They can cause an immune response in adults but are not helpful in infants and young children.
Recombinant vaccines are produced from a part of a virus that is not infectious to humans. These vaccines can help prevent several diseases in humans. The vaccines are made by inserting the genetic code of the target virus into bacterial or yeast cells. These cells then synthesize the surface protein of the virus. This protein is then purified and used as the active ingredient in the vaccine.
Live-attenuated vaccines contain weakened versions of the disease germ. These vaccines are used to create immunity against bacteria and viruses. They usually require one or two doses to develop protection against a particular disease. These vaccines are effective because they can elicit a strong immune response.