Adverse reactions followed by immunization is discussed here and we studied mainly the paediatric age group.

1. ADVERSE IMMUNISATION REACTION
Nabyendu Biswas
ADVERSE IMMUNISATION REACTION

2. “
”
HAZARDS OF
IMMUNIZATION

3. HAZARDS OF IMMUNIZATION
 No immune response is entirely free from the risk of
adverse reactions or remote squeal. The adverse
reactions that may occur may be grouped under the
following heads:
1. Reactions inherent to inoculation
2. Reactions due to faulty techniques
3. Reactions due to hypersensitivity
4. Neurological involvement
5. Provocative reactions
6. Others

4. These may be local general reactions. The local
reactions may be pain, swelling, redness,
tenderness and development of a small nodule or
sterile abscess at the site of injection.
 The general reactions may be fever, malaise,
headache and other constitutional symptoms.
Most killed bacterial vaccines (e.g., typhoid)
cause some local and general reactions.
Diphtheria and tetanus toxoids and live polio
vaccine cause little reaction.
Reactions inherent to inoculation:

5. Faulty techniques may relate to
 faulty production of vaccine (e.g. inadequate
inactivation of the microbe, inadequate
detoxication),
 too much vaccine given in one dose,
 improper immunization site or route,
 vaccine reconstituted with incorrect diluents,
 wrong amount of diluent used,
 drug substituted for vaccine or diluent,
Reactions due to faulty techniques:

6. Reactions due to hypersensitivity:
 Administration of antisera (e.g., ATS) may
occasionally give rise to anaphylactic
shock and serum sickness. Many viral
vaccines contain traces of various
antibiotics used in their preparation and
some individuals may be sensitive to the
antibiotic which it contains. Anaphylactic
shock is a rare but dangerous complication
of injection of antiserum. There is
bronchospasm, dyspnea, pallor,
hypotension and collapse.

7. Neurological involvement:
 Neuritic manifestations may be seen after
the administration of serum or vaccine. The
well-known examples are the postvaccinial
encephalitis and encephalopathy following
administration of anti-rabies and smallpox
vaccines.
 GuillainBarre syndrome in association with
the swine influenza vaccine is another
example.

8. Others:
 These may comprise damage to the fetus
(e.g., with rubella vaccination); displacement
in the age-distribution of a disease (e.g., a
potential problem in mass vaccination
against measles, rubella and mumps).

9. “
”
Adverse Events Following
Immunization,
AEFI

11. AEFI
 WHAT IS AN AEFI?
AEFI IS A MEDICAL INCIDENT AFTER AN
IMMUNIZATION AND IS BELIEVED TO BE CAUSED BY
THE IMMUNIZATION
 BASICALLY TWO TYPES
1.AVOIDABLE AND
2.UNAVOIDABLE

12. AEFI
Why monitor AEFI?
 No vaccines are 100% safe and without any risks
 It is important to know the risks and how to handle such an event
when it occurs
 Informing people correctly on AEFI helps keep public’s confidence
in the immunization programmes
 Monitoring AEFI also helps improve the quality of service

13. “
”
HOW CAN AEFI’S BE DETECTED?
WHAT MECHANISMS ARE
AVAILABLE?

14. AEFI
LIST OF AEFI
1. LOCAL ADVERSE EVENTS
2. CNS ADVERSE EVENTS
3. OTHER ADVERSE EVENTS

15. LOCAL ADVERSE EVENTS
1.INJECTION SITE ABSCESS
STERILE
BACTERIAL

16. FORMATION OF A STERILE ABSCESS
1. WRONG ROUTE (SC INSTEAD OF DEEP IM)
2. NOT SHAKING THE VACCINE BOTTLE BEFORE
DRAWING IN TO THE SYRINGE
3. WRONG DOSE (LARGER DOSE)

17. 2. LYMPHADENITIS
AT LEAST ONE LYMPH NODE 1.5 CM
IN SIZE OR DRAINING SINUS OVER
LYMPH NODE 2 – 6 MONTHS AFTER
BCG ON THE SAME SIDE AS
INOCULATION

18. 3. SEVERE LOCAL REACTION
REDNESS AND/OR SWELLING AT THE SITE WITH
ONE OR MORE OF THE FOLOWWING
1. SWELLING BEYOND JOINT
2. LASTING MORE THAN 3 DAYS OR
3. REQUIRES HOSPITALIZATION

19. AEFI
CNS ADVERSE EVENTS
1. ACUTE PARALYTIC POLIOMYELITIS
 WITHIN 4-75 DAYS
 RESIDUAL PARALYSIS AFTER 60 DAYS OR DEATH

20. AEFI
2. GBS
Guillain–Barré syndrome (GBS) also known as Landry's
paralysis, is a medical condition in which there is a rapid-onset
weakness of the limbs as a result of an acute polyneuropathy, a
disorder affecting the peripheral nervous system. The disease is usually
triggered by an infection, which provokes immune-mediated nerve
dysfunction. Many experience changes in sensation or develop pain,
followed by muscle weakness beginning in the feet and hands that
develops rapidly (between half a day and two weeks). During the acute
phase, the disorder can be life-threatening with about a quarter
requiring admission to intensive care unit for mechanical ventilation
OCCURING WITHIN 30 DAYS

21. 3. ENCEPHALOPATHY
CASES OCCURING WITHIN 72 HOURS AFTER VACCINATION
Encephalopathy is a term used to describe a constellation of signs and symptoms
reflecting a generalized disturbance in brain function.
Acute encephalopathy is the sudden onset of major neurological illness temporally
linked with immunization and characterized by two of the following:
I. Severe alteration in level of consciousness or unresponsiveness, with or without
generalized or focal convulsions. The symptoms must persist for more than a few
hours, with failure to recover completely within 24 hours.
II. Increased intracranial pressure (as measured and diagnosed by a physician). A
bulging fontanel as described by a parent to a nurse rather than observed by a
physician is not sufficient to diagnose increase intracranial pressure. Intense crying
can cause a bulging, pulsating fontanel.
III. Distinct change in behavior or intellectual functions lasting one day or more and felt
by a physician to indicate an alteration in neurological function.

22. AEFI
4. ENCEPHALITIS
CASES OCCURING WITHIN 72 HOURS
5. MENINGITIS
WITHIN 1- 6 WEEKS
SEIZURES – AFEBRILE
- FEBRILE

23. AEFI
OTHER ADVERSE EVENTS
1.ALLERGIC REACTION
2.ANAPHYLACTIC SHOCK
3.ARTHRALGIA
4.DISSEMINATED BCG-IT IS
5.HIGH FEVER

24. AEFI
OTHER ADVERSE EVENTS(CONT)
6. HYPOTENSIVE EPISODE (SHOCK/COLLAPSE)
7. OSTEITIS/OSTEOMYELITIS
8. PERSISTENT SCREAMING
9. SEPSIS (SEVERE GENERALIZED ILLNESS CONFIRMED BY BLOOD CULTURE)

25. AEFI
OTHER ADVERSE EVENTS(CONT)
10.TOXIC SHOCK SYNDROME
FEVER, VOMITTING AND WATERY
DIARRHOEA- FEW HOURS AFTER
IMMUNIZATION – OFTEN LEADING TO
DEATH

26. Examples of types & frequency of AEFIs
(in some common vaccines)
Vaccine Reaction
Onset
Interval
Rates per
million doses
Suppurative lymphadenitis 2-6 months 100 to 1000
BCG osteitis 1-12 months 1 to 700
Disseminated BCG-it is 1-12 months 2
Hib Nil known
Anaphylaxis 0-1 hour 0 to 2
Guillain-Barrè Syndrome (plasma derived) 1-6 weeks 5
Febrile seizures 5-12 days 333
Thrombocytopaenia 15-35 days 33
Anaphylaxis 0-1 hour 1 to 50
OPV Vaccine associated paralytic polio (VAPP) 4-30 days 1.4 to 3.4
Persistent (>3 hrs) inconsolable crying 0 -24 hours 1000 to 60000
Seizures 0 - 3 days 570
Hypotonic, hyporesponsive episode 0-24 hours 570
Anaphylaxis 0 - 1 hour 20
Encephalopathy 0 - 3 days 0 to 1
Post-vaccination encephalitis 7-21 days
400 to 4000 (in
infants <6 m)
Allergic/anaphylaxis 0-1 hour 5 to 20Yellow Fever
BCG
Hepatitis B
Measles/MMR
DTP

27. Reaction