VACCINES AND ANTISERA includes oral and par enteral

Classification vaccine and bites

1. VACCINES AND ANTISERA:

2. VACCINES AND ANTISERA: Vaccines and Antisera are biological products which enhance the immunological defence of the body against foreign bodies (mainly against the microorganisms and toxins)

3. VACCINES Classification

4. Vaccines provide two types of immunity Active immunity: Here the vaccines act as antigens, which induce production of specific antibodies by recipient himself. Act as prophylactic only Passive immunity : (Immunoglobulin and Antisera). Already prepared antibodies are given to the recipient (the antibodies are produced by another person or animal who have been actively immunized). The antisera and immunoglobulin are also curative The method of administration of vaccines/sera is called immunization/vaccination Active immunization is more efficacious and long acting than the passive immunization. Active immunity is slow acting (1-7 days), but passive immunity gives immediate protection Hence, the vaccines are mainly used for prophylactic purpose. The antisera is mainly for the treatment as well as prophylactic for short period The active immunity is very difficult in debilitated patients or immunocompromised individuals, who may not be able to generate an adequate antibody response and require passive protection

5. Vaccines are of 3 types 1 Inactivated vaccines consist of microorganisms killed by heat or by chemicals 2 Live attenuated vaccines contain live bacteria or viruses which have been rendered avirulant . The live microorganisms, however grow and multiply, which are sufficient to cause disease in AIDS, immunocompromised, leukemia, GC therapy etc., So, the live vaccines are contraindicated in them. 3 Toxoids: modified bacterial exotoxin, so that the toxicity is lost but antigenicity is retained Immunization schedule will be discussed in detail in Community Medicine/ Paediatrics

6. Bacterial vaccines: 1 Bacillus Calmette Guerin (BCG) for TB 2 Typhoid and Paratyphoid (TAB) 3 Cholera 4 Whooping cough 5 Meningococcal 6 Haemophilus influenza type ‘b’

7. Viral vaccines: 1 Poliomyelitis 2 Rabies 3 Influenza 4 Hepatitis-A 5 Hepatitis-B 6 Mumps (live attenuated) 7 Measles 8 Varicella Toxoids: Tetanus +Diphtheria Triple antigens (DPT) MMR-Measles, Mumps, Rubella

8. Actions of vaccines : The antibodies developed in response to live vaccines inactivate the bacteria/virus when they subsequently enter the body. Toxoids: The antibodies produced by toxoids neutralize the elaborated exotoxin. Viral vaccines generally afford more prolonged protection than bacterial vaccines. ANTISERA and Immunoglobulins ( Igs ) Antisera: The sera containing antibodies obtained from an animal (horse) immunized either by injection of antigen or by infection with microorganisms containing antigens. Immunoglobulins (IGs) are human gamma globulins which carry antibodies, They are more efficacious than antisera. Hypersensitivity reactions are rare.

9. Antisera Immunoglobulins 1) Antitetanus serum (ATS) 1) Tetanus immunoglobulin 2) Antirabies serum (ARS) 2) Rabies immunoglobulin 3) Antisnake venum (ASV) serum 3) Normal human gamma globulin 4) Antidiphtheria serum (ADS) 4) Anti-D immunoglobulin

10. 1) For Tetanus Tetanus immunoglobulin – is used as prophylactic in high risk patients and also as therapeutic Antitetanic serum (ATS) – is inferior to tetanus immunoglobulin and used only if Tetanus immunoglobulin is not available. 2) For Rabies Antirabies serum is used in individuals after suspected exposure. It is injected subcutaneously around the bite. Rabies immunoglobulin is injected subcutaneously around the wound for immediate protection, since Antirabies serum will produce active immunity only after 1-2 weeks.

11. 3) For Snake bite: Antisnake venum (ASV) serum contains antibodies to the venoms of cobra, krait and Russel viper, which 1 ml neutralizes, 0.6 mg of standard cobra venum , 0.6 mg of standard Russel viper’s venom, 0.45 mg of standard krait venum . 4) Anti-D-immunoglobulin (Anti Rh – Gammaglobulin ) to prevent Haemolytic Disease of new born (HDN): Rh – system of blood is named because it was found in Rheusus monkey. The person’s RBC, which carries Rh(O) antigen, is called as Rh+, and lack of that is called as Rh-. Rh+ is very common. But Rh- blood is very rare. Normally plasma does not have anti Rh-antibodies. But if a Rh- person receives Rh+ blood, then the body starts to make anti-Rh+ antibodies which will be circulating in the blood. For the first time, infusion of Rh+ blood into Rh- patient, there will not be any reaction. But the Rh- patients receive Rh+ blood for the second time, then there will be incompatibility with anti Rh+ antibodies and haemolysis may occur.

12. In Pregnancy : Such type of above incompatibility may occur in pregnancy and cause haemolysis in foetus , called as Haernolytic Disease of the New born (HDN). Normally there is no direct contact between foetal and maternal blood during pregnancy. Suppose maternal blood is Rh- and foetal blood is Rh+, there is a possibility of small amount of foetal blood (Rh+) may leak and mix with maternal blood, during pregnancy / abortion. The mother will start making anti Rh+ antibodies. The new born baby would not be affected for the first time. But in subsequent pregnancy the mother’s anti Rh+ antibodies can cross placenta and enter into foetal circulation. If the foetus is Rh-, then there will not be any problem, since there is no incompatibility. But if the foetus is Rh+, then there will be incompatibility with anti Rh+ antibodies and haemolysis may occur in the foetus , which is called as Haemolytic Disease of New born (HDN).

13. HDN can be prevented by giving Rh- mother an injection of an anti- Rhgammaglobulin (Rho(D) immunoglobulin) soon after delivery or abortion. These antibodies will bind to foetal Rh- antigen and neutralized it. The mother’s own immune system is spared from generating antibodies against these Rh+ antigens. The foetus of next pregnancy is also protected and is not at risk because the mother has no memory B-cell. The usual dose is Rho(D) immunoglobulin 2 ml (300 mg) / IM.