What Is Immunity?

Immunity (lat. Immanitas – liberation from duties) is an ability of body to resist infections and toxins. Immune system is most important system in human body. Immunity protects body not only from microbes that provoke infectious diseases but also from genetically foreign cells (parasites, enthetic tissues and even cancerous cells). Immunity to infectious diseases shows in several forms.

Natural immunity appears without conscious human intervention. It may be innate or adaptive.

1. Innate immunity (inherent immunity) is determined by characteristics transmitted heritably which are common to particular species. This is biological peculiarity of a specie which is resistant to particular infections. For example, humans never get infected with distempers and, instead, dogs never get infected with typhoid fever. Children in their first months of life have natural immunity to measles, scarlet fever, and diphtheria, which is connected with retention of protective antibodies that he got from mother who was diseased with them in past.

2. Adaptive immunity (acquired immunity) results from body reaction to entering of microbes in the body. It occurs after infectious disease or results from latent inflammatory process. Acquired natural immunity after ones infectious disease persists for a long time, sometimes for life (typhoid fever, chicken pox, measles, etc), and sometimes for a short time (influenza, etc). Immune system “remembers” all microorganisms which it faced before. Antibodies against them remain in the body for a long time or even for life. So when the microbe enters the body again, the immune system already knows how to fight it and as a result the disease courses in more mild form.

3. Artificial immunity appears after injecting vaccines or serum. Vaccination is performed routinely independently from morbidity rate. Serum with antibodies is used to provide rapid activation of immunity when infection has already occurred. The duration of artificial immunity is less than of natural immunity. Serum provides the duration of 2 – 3 weeks, and vaccines from several months to 5 – 8 years.

Obligatory vaccines are vaccines against tuberculosis, measles, poliomyelitis, diphtheria, tetanus, etc. Routinely are made vaccines to particular population groups, for example, vaccines against intestinal infections to workers of food enterprises, child-care centres, etc. In particular terms vaccines are made again (revaccinaction).

ARVI (Acute Respiratory Viral Infection)

ARVI (commonly known as cold) is a widespread virus disease of upper respiratory tract. Major symptoms: running nose, cough, sneezing, headache, sore throat, fatigue. ARVI is most common infectious disease in developed countries where in average an adult gets sick 2- 3 times a year and a child 6 – 10 times.

ARVI may be caused by a number of agents including 5 different groups of viruses (parainfluenza virus, influenza virus, adenovirus, rhinovirus, reovirus) and over 300 their subtypes. All of them are infectious and are transmitted via airborne and are not treated with antibiotics. Also ARVI is transmitted via body contact, for example, during hand shaking.

At the onset of the disease virus is multiplied in nose, nasopharynx, throat showing with gripes, running nose, irritation and dry cough. Body temperature usually is not increased. Sometimes in this process are involved mucous of eyes and gastrointestinal ones.

Then virus enters the blood and causes symptoms of common intoxication: chill, headache, acute pains in back and limbs. Activation of immunity response helps body to produce antibodies to the virus, after which blood gradually becomes clean from virus and then symptoms of intoxication decrease.

At he final stage of the disease occurs respiratory tract cleaning from epithelium damaged by virus which shows with running nose and humid cough.

Treatment and prevention
Prevention against ARVI mainly consists of general health improvement, body strengthening, immune system stimulation, regular exercises, taking vitamins, consuming healthy food, fruits and vegetables. When epidemic occurs, it is necessary to abstain from visiting public places , avoid close contacts with diseased people and wash hands more frequently. And same rules for diseased people – they should take a sick day, not visit public places, avoid contacts with healthy people and wear flu mask.

ARVI treatment commonly is symptomatic: plentiful warm drinking (not hot), taking vitamin C. You should know that taking antibiotics without doctor's recommendation is strongly prohibited because they do not have any effect on viruses and instead they get immunity down and cause disbacteriosis. It is not recommended to take antifebriles and painkillers when temperature is below 38 degrees C because moderate body temperature increase is a natural protective reaction of human body which helps immunity to fight viruses. When comes to antifebrile taking, patient should take Ibuprofen, most safe and effective medication today.

Use anti-viral medications to treat and prevent ARVI.