Essay on Vaccines

Essay on Vaccines!

Essay on the Evolution of Vaccines:

Over 200 years after Edward Jenner’s discovery (1798) 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 (1979), small pox from the earth.

The basic principle of vaccination remains quite the same as in Edward Jenner’s day; Jenner noticed that milkmaids who suffered from cow pox—a relatively harmless but contagious disease in cattle—did not contact the small pox.

So, Jenner took some cow pox germs from Sarah Nelmes, a young milkmaid, who had fresh cow pox lesions on her fingers, and inoculated an eight year old boy 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, 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 provided 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 Immuno Deficiency 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 the 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 Mumbai (India), since 1950 work was carried out for a leprosy vaccine. In 1965, the researchers could grow in the laboratory artificial medium a bacterium which 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 await more trials before it is sold.

During an epidemic of infectious diseases, a great significance is given to specific immuno-prophylaxis and immune therapy. Prophylaxis (Greek pro—before, phylasein—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°C to 40°C).

5. Associated vaccines (diphtheria, pertussis, 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.

Immunisation:

It 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 years of life.

Three in One:

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 visits. For the complete protection of the child, DPT injections should be given at the interval of 1 ¹/₂, 2¹/₂ and 3¹/₂ 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 the 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 the child attains the age of 9 months.

Is it Safe to Immunise a Sick Child?

Yes, it is safe to immunise a child suffering from any minor illness or malnutrition. All efforts should be made to get the child immunized even if he has mild fever, cough, cold, moderate diarrhoea 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 newborn 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 into the mother’s body and endanger 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 Immunisation Services:

Immunisation 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 illnesses, 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, diarrhoea, high fever, a paediatrician may be consulted.

Breast Feeding is Important:

Breast feeding 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 a rich source of antibodies and is produced in the breast during the first few days after the birth.

1. Immunisation 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. Immunisation 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 diseases 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 Immunisation 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 may 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.

Immunisation when:

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

2. Immunisation is urgent. It is very important to immunise a child early in life.

3. All immunizations should be completed within the first year of a child’s life.

4. 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.

Essay on the Adverse Reactions following Vaccines:

Some Instructions to Field Workers:

The reactions that follow vaccination are generally mild and of short duration. Serious reactions are known to occur but they are extremely rare and form a 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 deficiency 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.

Remember:

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

2. Immunisation 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’s life.

3. 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.

4. 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 arrangement 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 temperature 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 overemphasized. 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.  

Preventable Pediatric Diseases:

Tetanus:

Symptoms:

1. For the first two days of life, the newborn does normal suckling but keeps crying;

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

3. The child cannot open the mouth fully;

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

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

Danger:

The survival rate is very low.

Diphtheria Symptoms:

1. Sore throat with or without difficulties in swallowing;

2. Mild fever, no appetite;

3. The child looks ill;

4. Neck is swollen;

5. Whitish membrane in the throat;

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

Danger:

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

2. Diphtheria has high rate of fatality;

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

Pertussis (Whooping Cough):

Symptoms:

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

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

3. Breath is with a long in rush of air into the almost empty lung with a characteristic whoop;

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

5. The child often vomits after or during cough.

Poliomyelitis:

Symptoms:

1. The child has fever and headache;

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

3. Muscle pain with touch sense remaining normal;

4. Wasting of the affected muscles later.

Danger:

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

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

Measles:

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

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

3. Rash appears on the face between the third and seventh day, It appears over the whole body.

Danger:

1. 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:

Symptoms:

1. Low grade fever;

2. Swelling of lymph glands;

3. Loss of weight; cough and weakness; high fever;

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

5. The child becomes hunch-backed;

6. If not cared, the disease becomes fatal.

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

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

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

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

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

11. Polio drops are given orally when the child is brought for DPT. These drops are to be given when the child is 1 ½, 2½ and 3½ month of age;

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

So little care, so big a protection

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 the 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 responsibilities of the nurse is the administration of antigens and antibodies (immune sera). While shouldering this responsibility she should be able to intelligently understand 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 titres 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.