How do vaccine work?

Do not hesitate, lets vaccinate.

Greetings Chemistry Ninjas,

A vaccine is a type of medicine that trains the body’s immune system so that it can fight disease it has not come into contact with before.

Vaccination is the securest method to protect yourself against contagious illness. Once you have been vaccinated, you should have the capability to fight off the disease if you come into contact with it. They will have a level of protection, or immunity, against the disease.

But the important question is how do they work?

The network of cells, tissues and organs that work together helps us to fight off infection from the harmful bacteria in the immune system. When the virus enters our body, the immune system identifies it as harmful and will trigger a response to kill it.

Our immune system fights off infection by creating large proteins known as antibodies. These antibodies act as scouts, chasing down the infectious agent, and observing it for destruction by the immune system. Each antibody is specific to the bacteria or virus that it has detected and will trigger a specific immune response. These specific antibodies will remain in the immune system after the infection has gone. This means that if the same disease is encountered again, your immune system has a ‘memory’ of the disease and is ready to quickly destroy it before you get sick and any symptoms can develop.

Immunisation is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert between 2 and 3 million deaths each year - World Health Organization

Double click on the video to see the procedure:

Influenza vaccines (flu shots) can activate an immune response by mimicking viral infection. They are usually manufactured using inactivated or killed virus particles taken from various circulating influenza strains. Inactive fractioned viral components contain the sub various components hemagglutinin H and neuraminidase NA.

In Canada, influenza vaccines are administered via intramuscular injection. These fractioned particles containing the foreign antigens hemagglutinin and neuraminidase are released from the vaccine into the bloodstream. There they are met with an immune response mediated by various immune cells including macrophages, T lymphocytes or T-cells and B lymphocytes or B-cells. The major mechanism of action involves macrophage phagocytosis( the process by which phagocyte surrounds and destroys foreign substances and remove dead cells) of hemagglutinin breaking into smaller components. After ingestion, macrophages display the hemagglutinin antigen on their surface in combination with a specific receptor known as the major histocompatibility complex or MHC.

The function of MHC molecules is to bind peptide fragments derived from pathogens and display them on the cell surface for recognition by the appropriate T cells.

T-cells are now able to recognise and bind foreign antigens that are associated with the MHC. Upon binding to the MHC receptor, T-cells become activated and proliferated into either cytotoxic T-cells (a type of immune cell that can kill foreign cells, cancer cells, and cells infected with a virus), regulatory suppressor T-cells ( a type of immune cells that blocks the action of some other types of lymphocytes, to keep the immune system from becoming over-active) or helper T-cells (most important cells in adaptive immunity). Activated helper T-cells express hemagglutinin receptors specific to the vaccine strand on the surface and play a major role in antibody generation and memory B-cell activation.

Unlike T-cells, B-cells can ingest hemagglutinin independent of the MHC. Once internalised, B-cells processed the hemagglutinin antigen and presented it on their surface in combination with an MHC. When activated helper T-cells interact with activated B-cells expressing antigen MHC receptors they begin secreting lymphokines which have several effects.

Lymphokines is a protein released by lymphocytes, that affects other cells involved in the immune response.

Lymphokines trigger activated B-cell proliferation which leads to either differentiation into memory B-cells or plasma cells. Plasma cells produce hemagglutinin antibodies specific to the strain of influenza contained in the vaccine. Memory B-cells aid in the future immune response when exposed to an active influenza virus. When an infected host sneezes towards an uninfected person, the nasopharynx is exposed to aerosol droplets containing the whole live influenza virus. Once inhaled, the influenza virus attempts viral colonization of nasopharyngeal epithelial cells. Assuming that the vaccine strain matches that of the live virus, hemagglutinin antibodies block the viral attachment of live influenza virus to host epithelial cells and overall disease is avoided or diminished in severity.

But sometimes, the immune system doesn’t work against the harmful bacteria or virus and you can get very ill or – in extreme cases – die. Vaccination is the securest and most common way to gain immunity against a bacteria or virus that your body has yet to encounter. Vaccines have a harmless form of the bacteria or virus that causes the disease you are being immunised against. The bacteria or virus will be killed, greatly weakened, or broken down into small parts before use in the vaccine so that they can trigger an immune response without making you sick. Your immune system will still attack the harmless form of bacteria or virus from the vaccine and will produce antibodies to fight it off. The immune system then keeps a memory of the disease, so if a vaccinated person encounters the disease years later, their immune system is ready to fight it off and prevent an infection from growing.

Your immune system is there to protect you; by vaccinating yourself, you give your immune system all the tools it needs to keep them safe from many severe diseases - Meike Heurich-Sevcenco, BSI Vaccine Champion

What are vaccines made of:

Each vaccine will be made up of various elements depending on the disease it is targeting. The active ingredient in a vaccine is a very small amount of the killed, greatly weakened or broken-down parts of the bacteria or virus you are vaccinating against.

Sorbitol and Citric acid are added as preservatives and stabilisers in vaccines. These can already be found in the body or in food – usually in much larger quantities than the amount used in a vaccine. However, the most abundant ingredient in a vaccine is water.

Some vaccines also contain aluminium – usually in the form of aluminium hydroxide. Aluminium is found naturally in nearly all food and drinking water and is used in vaccines to strengthen and prolong the immune response they generate. The amount of aluminium in vaccines is extremely small and a recent study found that, in an infant’s first year of life, the total amount of aluminium in both vaccines and food is less than the weekly safe intake level.

Aluminium is also found in many other medicines, such as heartburn medication. Formaldehyde is used in the manufacture of vaccines. It is an organic compound that is found in many living things and humans produce formaldehyde naturally as part of the metabolic process. The high levels of formaldehyde can be harmful to humans, the amount of formaldehyde present in any vaccine is fifty times smaller than that found in a pear.

SOURCES :

GOOGLE BABA & YOUTUBE BHAIYA.

More is yet to come.

have a lovely day :)