which is better,viral immunity or bacterial immunity?

Give justification plz...

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  • 1 decade ago
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    Hi,

    Firstly, I should point out that there is no such thing as Viral immunity and Bacterial immunity . As humans immunity is not classifed based on the pathogens but based on the time of reaction, and type of cells that are involved in fighting foreign intruders. That is , in humans there are two types of immunity in the immune system , the INNATE IMMUNITY and the ADAPTIVE IMMUNITY. And both take part in both viral, bacterial as well as fungal , protozoal infection.

    But there is a difference between the 2 types of immune responses. The difference lie in the level of activeness against a specific pathogen. Usually , the Adaptive immune response is more important and more active in fighting viral infection , while the innate immune response is more about fighting off bacterial , fungal and protozoal infection. However , the Innate immune response is almost always the one to be activated first upon intrusion of a foreign organisms ( which can be immediately or as short as 6 hours of infection ) , while the adaptive immune response comes second as it NEEDS the activation and presentation ( signalling ) of the Innate immune response ( and this could takes up from 24 hours to days ). the adaptive immune response is mostly ONLY activated when the innate immune response has failed to give effective protection against the invaders. And frequently, both have to work closely together to give optimal protection.

    The Innate immune response : provides non-specific defences against infection including anatomical barriers ( your skin ) , phagocytic cells ( cells that eat ) , soluable molecules such as complement and acute phase proteins, and Natural killer cells ( cells that are licensed to kill ).

    If the whole innate immune system is described here, it is gonna be very long so I am gonna try to sum it up as effectively as possible. Firstly , the anatomical barriers that include your skin which continuously undergo renewal and replacement. The skin condition also provides some protection against bacteria such as slightly low pH (acidic ) , hydrophobic oils ( from sweat ) that help repel water and microorganisms. The sweat also contains lysozyme which destroy the bacterial wall 's intergrity. Also, mucuous membrane of the respiratory , gastrointestinal and genitourinary ( bladder, urethra ..) also secret mucus that can trap pathogens , and sIgA ( secretory immunoglobulin A ) which prevents both BACTERIA AND VIRUS from attaching and penetrating the epithelial cells. Even the bacteria , which coexist on/in human body ( which may be as high as 10^14 bacteria ) can effectively compete and kill other harmful bacteria....

    On a more cellular level , phagocytes such as macrophages play a very important role in the innate immune response. These cells basically find and eat the pathogens and induce inflammatory response ( most evidence is when you get a wound and the wound gets inflammed , u know macrophages and relatedly subsequent secreted molecules are at work ) , other cells such as monocytes and monocytes are also involved. These cells are able to recognise BACTERIAL CELL WALL , BACTERIAL DNA and VIRAL DOUBLE STRANDED DNA , and induce phagocytosis ( killing by eating ). You can know the evidence of active neutrophils when you see pus. These are usually dead neutrophils which already engulfed the foreign organisms, killed them and then terminated themselves and in turn got eaten by Macrophages. Neutrophils are great at producing a whole lot of chemicals that are toxic to bacteria and viruses. Side note : the excessiveness of neutrophil production and death hence pus production might lead to ABSCESS FORMATION. Macrophages unlike neutrophils, do not terminate themselves after killing, instead they are recycled for further use. Monocytes act the same way as macrophages.

    Other Innate immunse response cells/molecules are Cytokines which are very very toxic to foreign organisms and there are about 100 types identified. A few important ones are Interferon alpha which faciliates Antiviral activity , activates natural killer cells , macrophages and the adaptive immune response ( CD8 T cells ) , or tumor necrosis factor alpha which involves in inflammation , it is cytotoxic ( detrimental to the intergrity of the invaders ) , interleukins that partake in activating the ADAPTIVE immune response ...

    Second , the ADAPTIVE IMMUNITY ( which is much more important in fighting against VIRUSES - but is not exclusively called the VIRAL IMMUNITY ). The adaptive immunity is divided into 2 major systems. The adaptive immunity is highly adaptive, highly SPECIFIC , able to response to UNLIMITED NUMBER of molecules and has a "memory".

    - The humoral immunity which is B-cells immunity and immunoglobulins ( Ig's ) . B cells activation need help from T cells activation and posseses an ability to proliferate ( clonal expansion) and produce antibodies ( Ig's ). The antibodies ( IgA,C,D,E,M ) have several actions which ranging from stimulate phagocytosis , to neutralise pathogens and to provide long-lived protection against specific antigens ( bacteria and viruses ) after an individual has been exposed to/ infected with a particular pathogen.

    - The cellular immunity : which involves T cells ( mostly CD4 and CD8 T cells ) and extremely important against VIRUSES, FUNGI , and INTRACELLULAR BACTERIA. These cells can also regulate other cells of the immune system. The CD8 T cells( cytotoxic T cells ) when activated can kill the pathogens directly by forming spore molecules like perforins that burst the pathogens open, or induce apoptosis that bacsically destroys the foreigners. The CD4 T cells ( T helper cells ) mainly have regulatory functions by help mature B cells, activating CD8 T cells and interact very closely with phagocytes of the Innate immunity to regulate Cytokines production.

    I hope that helps ( it was a long-@ss essay wasnt it , lol)

    Source(s): 4th year med student.
  • 1 decade ago

    ... on the other hand, bacterial infections (esp. in the lungs, bloodstream, and lower GI tract) are far more bizarre and life-threatening than any of the garden-variety viral infections. In regards to the pneumonia comment, true bacterial pneumonia is quite rare in otherwise healthy people but can quickly get out of control. Viral pneumonias are almost never life threatening except in little kids, the elderly, or the immune-compromised. [by the way, fungal pneumonia is even more rare and probably the worst of all]

  • Shilo
    Lv 7
    1 decade ago

    viral immunity - because bacteria can be fought & killed with medicine.

    eg. viral pneumonia vs bacterial pneumonia - I would prefer bacterial pneumonia because if I have no immunity to the causative bacteria, I can be given an antibiotic to fight the infection. If it is viral pneumonia, I'm on my own.

    Edit: and everything else the guy above me said - LOL.

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