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Both ELISA and Western Blot are called indirect tests as they measure the immune system’s response to an infectious agent rather than looking for the components of the agent itself. Since ELISA detects HIV antibodies which the body starts to produce between 2-12 weeks after becoming infected with HIV, experts say that one should wait for at least 3 months after unprotected test to confirm for HIV AIDS. Western Blot is the most common method of testing to confirm positive results from ELISA test. Western Blot is used more as a confirmatory test as it is difficult to perform and requires high skills.

Fluctuations in internal body temperatures had no direct impact on the virus itself. Rather, it was the body's indirect immune response to the virus that differed, with a stronger response observed among the warmer lung cells and a weaker response observed among the colder nasal cells.Creative Diagnostics website explains the autoimmunity system-The immune system has very powerful effector mechanisms that can eliminate a wide variety of pathogens.

B cell activation requires two distinct signals, and results in B cell differentiation into memory B cells or plasma cells. and creative diagnostics company provides high quality antigens and antibodies. The first activation signal occurs upon antigen binding to B cell receptors (BCRs). Upon binding to the BCR, the antigen is internalized by receptor-mediated endocytosis, digested, and complexed with MHC II molecules on the B cell surface. The second activation signal occurs via either a thymus-dependent or a thymus-independent mechanism. Most B cell responses to antigen require the interaction of B cells with T helper cells

HIV is sensitive to high temperatures but not to extreme cold. Experiments have shown that HIV is killed by heat, but temperatures over 60°C are needed to achieve reliable killing of HIV. Levels of virus remain relatively stable in blood at room temperature, and HIV may persist for at least a week in dried blood at 4°C. Blood containing HIV used for laboratory experiments is stored at –70°C without any loss of viral activity. HIV may survive for up to four weeks in syringes after HIV-infected blood has been drawn up into the syringe and then flushed out.3 A study of blood gathered from more than 800 syringes filled with small amounts of HIV-infected blood and stored for various periods found that HIV could be isolated from 10% of syringes after eleven days where the quantity of blood was less than 2µl, but 53% of syringes where the quantity of blood was 20µl. Longer survival of HIV was also associated with lower storage temperature (less than 4°C); at higher temperatures (27 to 37°C) survival was not detected beyond seven days. HIV is very sensitive to changes in alkalinity or acidity – pH level – and pH levels below 7 or above 8 are unsuitable for long-term survival of HIV. One reason why HIV transmission may be less likely in healthy women is due to the acidity of vaginal secretions. HIV may survive in dried blood at room temperature for up to five or six days provided that the optimum pH level is maintained; drying of blood does not seem to affect the infectivity of HIV. Sewage is highly unlikely to pose a risk because infectious HIV has never been isolated from faeces or urine.5 However, research by Thames Water has shown that HIV can survive for several days in sewage in the laboratory. HIV does not survive as long as other viruses in sea water. Infectious HIV has been recovered from human corpses between eleven and 16 days after death in bodies stored at the usual mortuary temperature of 2°C. It is unclear how long infectious HIV may persist in corpses left to decay at normal room temperature, but HIV has been cultured from organs stored at 20°C up to 14 days after death. HIV was not detected in significant quantities later than 16 days, implying that buried corpses or those preserved for long periods pose less of a risk to undertakers and pathologists. No studies have investigated the survival of HIV in semen outside the body as such, but studies which have sought to culture HIV from semen in the laboratory have often found it difficult to do so, indicating the low quantities often present in semen.