Immunization of the Human Body

Immunization of the Human Body!

Almost 200 years after Edward Jenner’s discov­ery of small pox vaccination, mankind benefits from this process more than ever before. Several new vaccines were evolved and are now made available to eradicate many diseases, e.g., Jenner’s own first small pox vaccine has finally banished. In our time (1977), small pox disappearance from the earth.

The basic principle of vaccination remains quite the same as in Edward Jenner’s day; Jenner noticed that milk maids who suffered from cow pox, a rela­tively harmless but contagious disease in cattle, did not contract the small pox. So, Jenner took some cow pox germs from Sarah Nelmes, a young milk maid, who had fresh cow pox lesions on her fingers and inoculated an eight year old boy (James Phipps) with it. Later, he inoculated the boy again with the small pox germs and proved that the disease could not develop in the boy as the immune system of the boy started to act against small pox germs.

Louis Pasteur, almost hundred years later (1870- 80), discovered that a deadly germ could also offer protection against the disease it caused, if the germ is altered or killed and then injected. This provides a basis for developing at least 20 good vaccines. But recent advances in molecular biology and genetic engineering have led to a new era in vaccinology.

The first genetically engineered vaccine ap­proved in 1986, was designed to prevent hepatitis B which affects an estimated 200 million people around the world. This vaccine was produced by using sim­ple yeast cells into which was inserted the gene for the production of the disease causing virus’s outer coating. The outer coat itself is not infectious but, on recognising the outer coat, an immune response can trigger a protective reaction against the whole virus.

Though there was already a vaccine against hepatitis B virus, made by altering live viruses ex­tracted from the blood plasma of patients infected with the disease, it is suspected that all vaccines de­rived from blood products may carry the Acquired immunodeficiency syndrome (AIDS) virus or Human immunodeficiency virus (HIV).There will be no such risk in the new genetically engineered vaccine.

Recently, when a vaccine of bacterial meningi­tis was found to be only partially effective for babies under two, it was reengineered and an improved vac­cine was produced. Yet all these new findings and techniques have not made vaccine production easier in some cases, e.g., the common cold has no vaccine, because more than a hundred known viruses cause common cold. So, it is not possible to have a vaccine for each virus. And the influenza virus can change its form in every season. Therefore, any vaccine can become useless in a year.

Even worst is the HIV virus which changes its form at least twice as fast as influenza virus. Besides AIDS itself is a disease of immune system. However, a vaccine was produced which prevented AIDS in mon­key using inactivated monkey AIDS virus. This vac­cine cannot protect human beings against AIDS, as this monkey AIDS virus shares only 40 per cent of the genetic make-up with the human AIDS virus. Most experts believe that a human AIDS vaccine may take at least another five to ten years. Antiviral therapy against AIDS is under experimentation.

In Bombay (India), since 1950, work was carried out for a leprosy vaccine. !n 1965, the researchers could grow in the laboratory artificial medium a bac­terium seems similar to a close cousin of Mycobacte­rium leprae. They studied every characteristic of these new bacteria, treated them with radiation, experi­mented on animals injected into the first human sub­ject in 1979.

The first human subject had a single white patch on the skin. In a short time, the single white patch disappeared. Today, some 30,000 per­sons have been injected with this vaccine as a part of field trials in Maharashtra (India). None of these per­sons living in close contact with leprosy patients had any sign of leprosy infection. Yet this vaccine must wait more trials before it is sold.

During an epidemic of infectious diseases, a great significance is given to specific immunoprophylaxisand immune therapy. Prophylaxis (Greek, pro, before, phylasse in to guard or protect), is generally thought of being used in advance to prevent disease or infection.

Vaccine (Lat. vacca-cow) received its name from the anti-small pox preparation from the virus of cow pox. Vaccines are preparations consist­ing of attenuated or dead causative agents or prod­ucts of their life activity, while the method of inocula­tion is known as vaccination or immunization.

Vaccines are introduced parenterally or orally or intranasally within a definite period of time (from several days to several weeks). Vaccines give active immunity. Vaccines should be highly immunogenic (capable of causing sound and long immunity) and should not be toxigenic.

Modern vaccines which are under routine use:

1. Vaccines from live causative agents with a decreased (attenuated) virulence;

2. Vaccines from dead cultures of pathogenic microorganisms (bacteria, rickettsiae, vi­ruses);

3. Vaccines from the products of chemical cleavage of some bacteria (chemical vaccines);

4. Antitoxin (detoxified toxin by formalin at a temperature of 38° to 40°C);

5. Associated vaccines (diphtheria, pertussis, whooping cough and tetanus—DPT) vac­cine.

Serotherapy:

Sera are employed for treatment and prophylaxis of tetanus, gas gangrene, botulism. The length of protective action of sera by serotherapy (passive immunity) is from eight to twenty days. Gamma globulins obtained by the method of fractionation of serum protein by means of alcoholic solution of at temperature lower than 0°C, are used for prophylactic purposes against measles, poliomye­litis, whooping cough, serum hepatitis, small pox and are completely harmless as they do not contain hepa­titis B virus and causative agents of other diseases.

Immunization is an answer to the life saving pro­tection against childhood diseases. Five gentle pricks for life saving protection against childhood diseases. An infant has to be immunized five times before he completes first year of life.

1. Soon after birth

One BCG injection against tuberculosis.

2. At the age of 1½ months

One DPT injection against

Diphtheria, Pertussis, Tetanus and first dose of polio drops.

3. At the age of 2½ months

Second dose as above.

4. At the age of 3½ months

Third dose as above.

5. At the age of 9 months

One injection against measles.

Three in One (3 in 1):

For protection against three killer diseases (diph­theria, pertussis — whooping cough and tetanus), three vaccines are given together in a single injec­tion called DPT. Dose of polio drops are also given along with DPT to avoid repeated visit. For the com­plete protection of the child, DPT injections should be given at the interval of 1½, 2½ and 3½ months.

To be borne in mind:

(i) If, due to some reason, the child is not immunized in time, it is vital to have the child immunized at the earliest possible there­after;

(ii) There should be at least a gap of one month between two doses of immunization;

(iii) It is essential for the infants to complete full course of immunization. If the pre­scribed repeat doses of immunization are not taken, the child will not have full pro­tection from killer diseases;

(iv) Vaccination against measles is recom­mended at nine months of age, because, for the first few months of the life, the child has natural protection against it in­herited from the mother. After about 9 months the natural protection comes to an end and the child must be immunized against the risk of measles as soon as it attains the age of 9 months.

Is it safe to immunise a sick child. Yes, it is safe to immunise a child suffering from minor illness or mal­nutrition. All efforts should be made to get the child immunized even if he has mild fever, cough, cold, moderate diarrhea or some other mild illness on that day. No time should be lost in having him protected from the dangerous diseases before it is too late.

Protection of women against tetanus:

(a) In many parts of our country, mothers give birth in unhygienic conditions. Hence, the mother and new born are at risk of teta­nus;

(b) Tetanus bacilli grow in dirty wounds made by an unclean knife used to cut the um­bilical cord during delivery. The knife to be used should be first cleaned, boiled or heated in flame and allowed to cool be­fore use;

(c) If the mother is not protected against the tetanus, the exotoxin liberated by tetanus bacilli in the infected wound may be ab­sorbed in to the mother’s body and en­dangers the life of both mother and child;

(d) Tetanus toxoid (TT) injections at one month’s interval are necessary as soon as the mother becomes pregnant. If she is already immunized, then one injection is enough;

(e) As a rule, every woman between the age of 15 and 44 years should be fully immunized against tetanus. Every woman who becomes pregnant should make sure that she is immunized. All infants should be immunized against tetanus during the first year of life.

Where to get the immunization services:

Immunization services can be obtained free of cost from all health, family welfare, primary health centre and public hospitals throughout the country.

Adverse effects of vaccines:

Vaccines for immunization have no side effects. A child may cry after an injection, develop slight fever, rash or small sore. As with other illness the child may be given plenty of fluid and food and it may be alright soon. If the prob­lem is serious and the child has vomiting, diarrhea, high fever, a pediatrician may be consulted.

Breast feeding is important:

Breastfeeding is a kind of natural immunization against several diseases. Mother’s resistance to disease is transferred to the child through her milk, i.e., the thick yellow milk (co­lostrum) which is rich source of antibodies and is pro­duced in the breast during the first few days after birth.

1. Immunization protects the pregnant woman against tetanus and the children against several dan­gerous childhood diseases, i.e., three killer diseases (diphtheria, pertussis, tetanus (DPT)), tuberculosis and measles;

2. Immunization is provided through vaccines which are given orally or parenterally;

3. The child’s body defence mechanism against diseases is built up by vaccination. If the disease strikes before the child is immunized, then the immunization is too late;

4. Children who survive the diseases are weak­ened and may die later from nutritional deficiency and other illness. The diseases may hamper the child’s growth and development.

Why Immunization is of Great Necessity:

If the child is not immunized:

(a) He is more likely to become undernour­ished, disabled or to die;

(b) The child is likely to get measles and whooping cough. These diseases can kill the child. Measles is also an important cause of mental retardation and blindness;

(c) The child can be infected with polio virus which can cripple him for life;

(d) The child is exposed to the danger of teta­nus which kills most of the people who become infected.

It is the right of every parent to ask for immunization for the protection of their children.

Immunization when:

i. Protection of the child has to begin right after a woman becomes pregnant. This is done by injection of TT to the mother at one month interval at the earliest possi­ble after conception.

ii. Immunization is urgent. It is very impor­tant to immunise a child early in life.

iii. All immunizations should be completed within the first year of a child life.

iv. Half of all deaths from whooping cough, one-third of all cases of polio and one-fourth of all deaths from measles occur before the age of one year.

Adverse reactions following vaccines:

Some instructions to field workers:

The reactions that follow vaccination are gen­erally mild and of a short duration. Serious reactions are known to occur but they are extremely rare and forma small fraction of similar type of complications that occur as a result of disease itself. Neurological syndromes can also occur spontaneously in infant and vaccination may only be coincidentally related.

The common reactions are mild fever, redness, tenderness and pain at the site of injection. Fever and rash on the sixth or seventh day after measles vacci­nation have also been reported. The number of severe reactions and deaths fol­lowing vaccination are rare.

Measures to Minimise Risks:

The following measures are to be followed to minimise risks of adverse events following vaccina­tion:

1. Vaccination sessions should be held on fixed days. The children should be collected at the sub-centre at a central point of a village. Door to door vaccination should not be practiced as such a strat­egy carries a high risk of break in the cold chain and contamination of the syringes and needles.

2. Procedures for sterilisation of syringes and needles should be scrupulously followed and moni­tored whenever feasible, steam sterilisation should be preferred to boiling:

i. Single sterile syringe and a single sterile needle are used for each injection.

ii. Issue of the vaccine to the field staff should be strictly monitored. Only re­quired quantities of the vaccine should be taken from the primary health centre on the day of the session.

iii. Vaccines may be taken on the previous day only if these are carried in vaccine carrier with fully frozen icepacks.

iv. Supervision should include measures to ensure that vaccine vials are not stored in the periphery and reused subsequently. Batch number and expiry date should be recorded before issue.

v. Vaccine should be discarded at the end of the session. Opened vials of vaccine should not be reused under any circum­stances.

vi. Potentially harmful injectable drugs should be kept separate from vaccine vials and diluent.

vii. Field monitoring of the services must be regular so that any deficiencies could be noted and corrected in time. Reporting of abscesses by the health workers in their areas should be made compulsory.

viii. Measles vaccine should be reconstituted with the diluent provided with the vaccine. The diluent should be cooled before use. The vaccine should be kept on ice while in use. The children should be ad­ministrated 0.5 ml of the vaccine in the arm subcutaneously. A separate sterile syringe and needle should be used for each injection. (Extract from “National Immunization Mission” — Ministry of Health and Family Welfare — 1989, New Delhi, India).

Remember:

a. An unimmunized child is more likely to become disabled, undernourished and to die.

b. Immunization is no less important than the mother’s love for a baby. It is urgent. It has to begin soon after birth and completed within the first year of a child life.

c. The last dose of Tetanus toxoid (TT) injec­tion during pregnancy for protection against tetanus must be had at least thirty days before the expected date of deliv­ery and also for protecting the child to be born against neonatal tetanus.

d. For protection against three killer diseases, three vaccines are given together in a sin­gle injection called DPT.

Cold Chain for Vaccine:

Vaccines are thermolabile products, hence they require special storage and transportation arrange­ments to retain their efficiency. If vaccines are kept at the recommended mini­mum temperature, they will remain potent for a longer period of time. All vaccines retain their po­tency at temperature +2 to +8 degree C. The vaccines must be transported and stored at these tempera­tures at district and primary health centres.

For long term storage, measles and polio vaccines are kept at sub-zero temperature. If freez­ers are available these vaccines should be kept in a freezer. DPT, DT and TT vaccines should not be fro­zen. Vaccines should not be exposed to direct sun­light. The cold chain for vaccines consists of three vital elements — the cold storage equipment, trans­portation and motivated and trained manpower for operating the vital link.

The importance of people in the cold chain cannot be over emphasised. Often the cold chain is thought to refer only to the refrigeration of the vac­cine. Even if the finest and most modern equipment and transportation are available the cold chain will not be effective, if the people do not handle the vac­cine properly. Several steps have been taken over the last few years to strengthen the cold chain for vaccines. The activities have been directed both at improving the storage and transportation facilities as well as in training manpower in logistics of vaccines and han­dling of the refrigeration.

(Excerpts from the publication “National immunization Programme” published by National Institute of Health and Family Welfare, New Delhi, India).

Diseases:

Tetanus:

Symptoms:

a. For the first two days of life, the new born does normal suckling but keeps crying;

b. The infant is unable to suckle between 3rd and 21st day;

c. The child cannot open the mouth fully;

d. Facial, neck and trunk muscles of the child get stiff and the child gets convulsions;

e. His body bends like a bow due to the con­traction of neck and trunk muscles.

Danger:

The survival rate is very low.

Diphtheria:

Symptoms:

a. Sore throat with or without difficulties in swallowing;

b. Mild fever, no appetite;

c. The child looks ill;

d. Neck is swollen;

e. Whitish membrane in the throat;

f. The child has difficulty in breathing due to obstruction in airways.

Danger:

a. The toxin can affect the heart muscle and nerves;

b. Diphtheria has high rate of fatality;

c. It is highly infectious, painful and danger­ous for the children.

Pertussis (Whooping Cough):

Symptoms:

To begin with, the child has slight fever, running nose, cold and cough;

a. Gradually, cough gets worse, child gets fits of cough and struggles for breath;

b. Breath is in noisy whoop;

c. Spasms are common during cough, the eyes bulge and bleed;

d. The child often vomits after or during cough.

Poliomyelitis:

Symptoms:

a. The child has fever and headache;

b. Feels sudden onset of weakness and pa­ralysis generally of one leg or arm or trunk;

c. Muscle pain with touch sense remaining normal;

d. Wasting of the affected muscles later.

Danger:

a. Paralysis of one of the limbs leading to lameness;

b. May even lead to paralysis of muscles of respiration.

Measles:

Symptoms:

a. The disease starts with fever, running nose and cough;

b. The child’s eyes become red and watery;

c. Rash appears on the face between the third and seventh day.

It appears over the whole body.

Danger:

a. The child gets weak, becomes prone to secondary infections of lungs, ears, eyes and gastrointestinal tract. It can be fatal due to complications like pneumonia.

Tuberculosis (Childhood):

Symptoms:

a. Low grade fever;

b. Swelling of lymph glands;

c. Loss of weight; cough and weakness, high fever;

d. Severe headache, stiffness of the neck and convulsion in the case of tuberculosis meningitis;

e. The child becomes hunch-backed;

Danger:

a. If not cared, the disease becomes fatal.

Recommended age for BCC vaccination against tuberculosis is just after birth; only one dose is given.

a. At the age of five years, an injection of DT and one injection of TT at the age often and again at sixteen years particularly in the case of girls;

b. Interval between two doses of vaccina­tion should not be less than one month;

c. Vaccination for immunization can be got done without hesitation even in the case of minor cough, fever, diarrhea, in consul­tation with a physician or health worker;

d. For the health of the child, it is essential to have the child vaccinated at the right time;

e. Polio drops are given orally when the child is brought for DPT.These drops are to be given when the child is 1½, 2½ and 3½ months of age;

f. BCG injection is given for protection against tuberculosis to the infant at birth, only one injection is enough.

Application to Nursing:

The knowledge of immunology is extremely essential for the professional nurse in her day-to-day practice and is of great importance, particularly, for public health nurse. Public health nursing can be very effective, if the nurse could teach about the basic facts of immunology — why the administration of specific antigens are important to the health of the children and how the epidemics are controlled and how the susceptible individuals can be protected against the dreadful diseases.

One of the frequent responsibility of the nurse is the administration of antigens and antibodies (immune sera). While shoul­dering this responsibility she should be able to un­derstand intelligently what are to be administrated with precaution, their adverse reactions and the ex­pected results of the immunization.

In conducting the field trial programme of a newly developed vaccine, the nurse is one of the important members of the team to find out the effi­cacy of the administration of the antigens. Besides this, the nurse has a great role to collect data and to convince the people to participate in the full pro­gramme by explaining them in explicit clear local language.

Because of her sound knowledge of im­munology and immunization schedule, she will be able to communicate the parents the importance and necessity of repeated childhood vaccination at fixed time interval and about the blood collection for the evaluation of antibody titers in the blood after vacci­nation.

In public health nursing, since the nurse is al­ways in touch with the public, she will be the first person to recognise the necessity of active and pas­sive immunization in an individual, family, commu­nity, for this important and quick decision, she should be well equipped with the essential knowledge of immunity and she can transmit this information to the higher authority who will be responsible for the immunization of the public living in that situation.

The nurse is always on the frontline and comes in close contact with the patients because of the na­ture of her work; and she is always at the risk of get­ting infected with the communicable diseases dur­ing epidemics. Therefore, she should maintain the highest degree of protection against all these dis­eases for her own good health and life by regular immunization.