Immunisation Update By Sindy Lee & Eva Wong 27 th March 2003.

Immunisation UpdateBy Sindy Lee & Eva Wong27th March 2003

Case 1 Mr and Mrs Chan bring their 2 month

old daughter, Siu-yee for her first immunisation. They say that they have received a reminder letter from the government and ask what their child what their child requires.

Question 1 What immunisation does the child no

w require?

Question 2 How and in what sites are these immu

nisation given?

Question 3 How should these vaccines be

stored?

Question 4 Where and how should the

vaccination be recorded?

Question 5 The parents ask about possible

reactions to the vaccines. What advice would you give about possible adverse reaction?

Question 6 Mr Chan returns in 2 months for Siu ye

e’s sencond immunisation and tells you she had a fever after her last immunisation. She cried during the night. What questions would you ask Mr Chan? What would you advise about this immunisation?

Question 7 You next see Siu-yee at the age of 6 m

onths when she has a slight rhinitis but no fever and her chest is clear. Would you give her immunisation? What precaution would you take?

Case 2 Siu-ming, an 18 month old infant is br

ought for his fourth triple antigen immunisation. You have not seen him before.

Question 1 What information would you

requires before giving the injection?

Question 2 The parent informs you that Siu-ming

had his 12month booster at another private doctor’s clinic. The boy has not had an examination since relocating 12 months ago. What questions would you like to ask about his general health and development?

Question 3 What examination would you

perform?

Question 4 The parent informs you that although there

are no hearing problems in the family, Siu-ming does not seem to turn around when spoken to. Otoscopic examination reveals some mucosal swelling and a dull drum on the left side. He has a slight post-nasal drip but is afebrile.

Would you give his immunisation?

Question 5 What is your management of the

ear problem?

Case 1 Mr and Mrs Chan bring their 2 month

old daughter, Siu-yee for her first immunisation. They say that they have received a reminder letter from the government and ask what their child what their child requires.

Question 1 What immunisation does the child no

w require?

Question 2 How and in what sites are these immu

nisation given?

Case 1- answer 1, 2

Immunization programme in Hong Kong 2003Newborn BCG

Oral polio type IHepatitis B vaccine – first dose

1 month Hepatitis B vaccine – second dose

2-4 months Triple vaccine (diphtheria, tetanus & pertussis) – first doseOral polio trivalent – first dose

3-5 months Triple vaccine (diphtheria, tetanus & pertussis) – second doseHepatitis B vaccine – third dose

4-6 months Triple vaccine (diphtheria, tetanus & pertussis) – third doseOral polio trivalent – second dose

12 months MMR vaccine (measles, mumps, rubella) – first dose

18 months Triple vaccine (diphtheria, tetanus & pertussis) – booster doseOral polio trivalent – booster dose

Primary 1 Combined vaccine (diphtheria & tetanus) – booster doseOral polio trivalent – booster doseMMR ( measles, mumps & rubella) – second dose

Primary school student BCG after tuberculin testing

Primary 6 Combined vaccine (diphtheria & tetanus) – booster doseOral polio trivalent – booster doseSupplementary hepatitis B vaccination

Elderly > 65 years old in institutions

Influenza

intradermal













Influenza













Influenza

intramuscular













Influenza

intramuscular













Influenza

Subcutaneous

Question 3 How should these vaccines be

stored?

Case 1- answer 3 Stored 2-8C Upper deck:

oral polio, MMR, BCG, rebella Middle deck:

hepatitis B, DTP, flu Lower deck: emergency medication, NS Thermometer for monitoring Not to store with other foods Minimize opening New drug at the back

Question 4 Where and how should the

vaccination be recorded?

Case 1- answer 4 In practice record In child health record Immunization record Information:

Date Vaccine Adverse reaction Expiratory date and serial number

Question 5 The parents ask about possible

reactions to the vaccines. What advice would you give about possible adverse reaction?

Case 1- answer 5 BCG: local reaction Polio: poliomyelitis (1/6.2million) DPT: fever, seizures HBV: rare MMR: fever, rash, joints pain

Question 6 Mr Chan returns in 2 months for Siu ye

e’s sencond immunisation and tells you she had a fever after her last immunisation. She cried during the night. What questions would you ask Mr Chan? What would you advise about this immunisation?

Case 1- answer 6 ? Body temperature Describe the crying If temp >40.5C or crying >3-4 hr, child

should preclude further pertussis vaccination

Consider prophylactic panadol

Question 7 You next see Siu-yee at the age of 6 m

onths when she has a slight rhinitis but no fever and her chest is clear. Would you give her immunisation? What precaution would you take?

Case 1- answer 7 Rhinitis not a contraindication Principles:

Careful education Management of fever Immunisation should not be inappropriat

ely deferred due to infection

Case 2 Siu-ming, an 18 month old infant is br

ought for his fourth triple antigen immunisation. You have not seen him before.

Question 1 What information would you

requires before giving the injection?

Case 2 – answer 1 Check previous immunisation record Any adverse reaction Allergies Past medical history Neurological diseases

Triple vaccine Contraindication:

Acute febrile illness Active or progressive neurological diseas

e Previous severe reaction e.g. encephalop

athy within 7 days after previous injection, immediate severe allergic or anaphylactic reaction

Triple vaccine Relative contraindications

Convulsion within 2 days Persistant, inconsolable screaming for m

ore then 3 hours within 2 days Collapse or shock like state within 2 days Unexplained high fever with 2 days Sever local reaction

Triple vaccine NOT contraindications:

Family history of adverse reaction Family history of convulsion Permaturity Asthma, eczema, allergies Stable neurological condition

Question 2 The parent informs you that Siu-ming

had his 12month booster at another private doctor’s clinic. The boy has not had an examination since relocating 12 months ago. What questions would you like to ask about his general health and development?

Case 2 – answer 2 Check previous health record Discuss developmental milestone

Question 3 What examination would you

perform?

Case 2- answer 3 Height and weight Strabismus Gait Abdomen and testis CVS

Question 4 The parent informs you that although there

are no hearing problems in the family, Siu-ming does not seem to turn around when spoken to. Otoscopic examination reveals some mucosal swelling and a dull drum on the left side. He has a slight post-nasal drip but is afebrile.

Would you give his immunisation?

Case 2- question 4 There is no contraindication

Question 5 What is your management of the

ear problem?

Case 2 – question 5 Dx: serous otitis media Take 3 months to resolve Conservative management Refer ENT if parents concern or persis

tent symptoms Prevent learning and language develo

pmental problem

Categorization of vaccines

BCG

Live or inactivated ?Live attenuated

Inactivated

Live attenuated Live attenuated

Live attenuated

Hep B surface anitigenD&T toxoid, killed P organismInactivated vaccine

InactivatedHaemophilus influenzae type B

Influenza

DPT

Hepatitis B

Chickenpox

MMROPVIPV

Are they contraindication for vaccination?

Family history of any adverse reactions following immunisation Family history of convulsion or epilepsy Prematurity Symptomatic HIV History of anaphylactic reaction Neurological conditions, such as cerebral palsy and Down’s syndr

ome Those on immunosuppressive agents eg. steroids Asthma. ezema, hay fever, rash to egg protein to receive MMR Those on antibiotic or inhaled steroid Pregnancy Child is being breastfeed Under a certain weight Chronic illness eg. congenital heart disease

No

NoNo

Yes

Yes

NoNo

NoNo

YesNo

NoNo

Routine immunization programme - BCGCharacteristicCharacteristic::Intradermal, papule will appear 2-6 wee

ks then dischargeEfficacy:Protect against disseminated disease a

nd TB meningitis in particular 80%About 50% protection against pulmona

ry TB

Routine immunisation – BCG Adverse reaction 1-2% Prolonged deep ulceration, subcutan

eous abscess Lymphadenitis 1-10% Osteomyelitis 5/100,000 in newb

orn Disseminated disease <2/1,000,000

Routine immunisation - BCG Contraindications

Children born to HIV-positive mothers Those at risk of severe immunodeficiency Symptomatic HIV (if asymptomatic, asses

sed by paediatrician for fitness) Those receiving immunosupressive agent

s Pregnancy

Routine immunisation – Poliovirus vaccine Immunogenicity and vaccine efficacy:Immunogenicity and vaccine efficacy:

Seroconversion

OPV IPV

3 doses >95% 99%

Inhibit acquisition-intestinal

+++ +

Routine immunisation – Poliovirus vaccine

How long did the faecal excretion of OPV last?6 weeks

What happen if the child vomit after ingestion of OPV? Repeat if vomiting within 10 minutes. If not retained, repeat 4 weeks later.

Routine immmunisation – Poliovirus vaccine

OPV IPV

Timing of Timing of vaccinationvaccination

2 separate doses (8 wks, min 6 wks) & a booster dose at 18 months ( min 2 mths after).

2 injections (8 wks, min 4 wks) & a booster dose 1 year after

Adverse effect:Adverse effect: Paralytic poliomyelitis (1/6.2 million) Contraindication:Contraindication: Anaphylactic reaction to a vaccine or any of its components (eg. Ne

omycin, streptomycin, polymyxin B)

Routine immunisation - DPT

Adverse event:Adverse event: Local and febrile reaction Bacterial or sterile abscesses 6-10/million Allergic reaction – anaphylaxis 2/100,000 Seizures – febrile seizures Hypotonic-hyporesponsive episode 4-291/100,000 Fever of 40.5 0.3%

Pertussis Diphtheria toxoid

Tetanus absorbed toxoid

Efficacy 50-90% 97% 100%

Routine immunisation – DPT Contraindication:Contraindication: An immediate anaphylactic reaction Encephalopathy within 7 days

Is history of febrile convulsion a contraindication for DPT vaccination?

How would you advise him?

Routine immunisation - DPT Management of Children with history of Management of Children with history of

febrile convulsion after DPTfebrile convulsion after DPT1. Administration of panadol at the time of DPT and at 4-8 ho

urs after immmunisation decreases the subsequent incidence of febrile and local reactions. Antipyretic prophylaxis every 4-6 hours for as long as 24 hours after vaccination may benefit children with increased risk of seizures, including febrile convulsions

2. Tepid sponging3. Regular checking of body temperature

Routine immunisation - MMRMeasles Rubella Mumps

EfficacyEfficacy 99% 99% 96%

Adverse Adverse reactionreaction

1. Fever 7-12 days after 5-15 %

2. Rash 5%3. Allergic reaction4. Seizures –

simple febrile5. Thrombocytope

nia 2-4/400,000 doses

6. Encephalitis - < 1 per million doses

1. Arthopathy 0.5%

2. Transient peripheral neurotic compliants

1. Rash2. Febrile

seizures3. Nerve

deafness4. Meningitis,

encephalitis

Routine immunisation - MMR Contraindication:

Anaphylactic reaction to a vaccine or its components ( eg gelatin, neomycin)

Immunodeficiency due to causes other the HIV Symptomatic HIV Pregnancy

Routine immunisation – Hep B Efficacy:Efficacy: 90-95% Immune memory remains intact for >13 years Schedule:Schedule:

Three doses at birth, 1 and 6 months Very low birth weight infants Infants < 2 kg respond poorly to vaccine If mother HbsAg pos : start HBV vaccination with HBIg at birth If mother HBsAg neg : start HBV vaccination when BW > 2 kg Children under 6 years with incomplete course of vaccination ( the 3 doses) Received 2 doses 3 wks to 3 mths apart and within 1 year after second dose –

give the third dose Supplementary Hep B vaccination for primary 6 students

Vaccine Storage and Handling

Protect MMR from light at all times

Freeze (-14 or lower)Freeze (-14 or lower) Refrigerate (2 – 8 )Refrigerate (2 – 8 )

OPVVaricella

MMRDPTHibHepA, HepBInfluenzaIPVPneumococcal

Polio vaccine

Oral polio vaccine VS inactivated polio vaccine

Polio vaccine Oral polio vaccine

Developed 1961 Live attenuated vaccine Cheap and easy to administer Humoral antibodies as well as intestinal immunity Short term shedding of vaccine in stool also result in “p

assive immunization” of persons with close contacts Risk of vaccine-associated paralytic poliomyelitis (VAPP) Declared polio-free in Oct 2000 in Western Pacific Risk of VAPP greater then risk of paralytic poliomyelitis fr

om wild-type poliovirus

Inactivated polio vaccine Global eradication targeted at

2005 Change to IPV?

Inactivated polio vaccine (IPV) Developed 1955 Immunogenicity is low Replaced by enhanced-potency IPV No risk of VAPP Disadvantages:

Expensive Needs additional injections IPV vaccinee is infected by wild polio, virus can s

till multiply and shed in stool risking continued circulation among the community

Inactivated polio vaccine (IPV) During polio outbreak: OPV WHO recommendation:

Countries currently involved in polio eradication should not consider using IPV at this moment and OPV is required for actual eradication

Recently or currently endemic countries should continue EXCLUSIVE OPV

Is HK ready to switch to IPV? Last case of poliomyelitis caused by

wild poliovirus occurred in HK in 1985

Some Nearby areas still endemic South Asia countries reported 80% of

global cases of polio in 1998 Indian subcontinent Sub-Sahara Africa

Lack of data about risk of VAPP

Polio vaccination in HK Oral trivalent vaccine introduced in 1963 Resurgence of polio type 1 in 1965 Oral polio type 1 to newborn in 1966 1971: Booster doses of trivalent vaccine

at 18mo 1979: booster doses at P.1 and P.6 Strategy need review after global

eradication of polio

Influenza vaccine

Influenza vaccine Epidemiology:

Two peaks: Jan-Mar, Jun-Aug 2- 3 types of influenza viruses

Multivalent Component will be determined each year fo

r northern and southern hemisphere 97/98: Bayern(H1N1), Wuhan(H3N2) 98/99: Sydney(H3N2), Beijing(H1N1)

Influenza vaccine Inactivated vaccine Safe Efficacy

age and immunocompetence of recipient degree of match/similarity between vacci

ne strains and virus in season If antigenicity similar, prevents illness in

70% - 90% of healthy persons <=65years

Influenza vaccine- how to use? Different strain each year Annual vaccination 1998: annual immunization of

residents in elderly homes in HK Given 2-4 months before its peak

October to December Route: IM, 0.25-0.5ml

Influenza vaccine- who should receive it? DH

All persons >65years Residents of nursing home

HA Children with hemodynamically significant conge

nital heart disease, chronic lung disease (+/- asthma), children on long-term aspirin, hemoglobinopathies, psychogeriatric inpatients, institutionalized mental handicapped patients

Private: Anyone who wishes to reduce risk of influenza

Intranasal influenza vaccine Trivalent, live attenuated cold adapte

d vaccine Effective (93% effective in preventing

culture-positive influenza) and safe Protective even in the second year wit

h serotype mismatch (86% effective) No injection needed

Hepatitis A vaccine

Hepatitis A- epidemiology Incidence decreasing due to better

hygiene Fecal-oral route: hygiene >

vaccination Usually has a benign course 51% of Guangzhou province and

15% HK has HA antibodies Expensive

Hepatitis A Two inactivated hepatitis A vaccines

available Approved for persons > 2 years of age Pediatric formulation available

Different units but 0.5ml IM for both 2 doses (initial and at least 6 months later)

Hepatitis A 88-100% seroconverted after 1st dose,

100% after 2nd dose Protective efficacy for clinical hepatiti

s A of 94-100% Need for booster dose not known yet,

kinetic models suggest that protective levels will persist for > 20years

Hepatitis A Routine immunization for areas with rates >

=20/100000 in the US Hong Kong

Limited to high risk groups: travellers to endemic areas, chronic liver disease, laboratory workers, food handlers, health care workers

Not routinely recommended for children “personal decision” Not a substitution for high standard of hygiene

Varicella vaccine

Varicella vaccine Epidemiology:

Over 90% of children infected by 8 years Highly communicable Complications uncommon but serious Great economic impact Treatment of acyclovir remains in doubt

Varicella vaccine Routine pre-exposure administration

Overall 80-85% protection from infection Milder disease for clinical disease

Post-exposure prophylaxis Varicella-zoster immunoglobulin (VZIG)

within 96 hours of exposure: efficacy 50%, protection period unknown

Oral acyclovir: inadequate studies Post-exposure immunization: encouragin

g results in Japan and US

Varicella vaccine- post-exposure use Prevention of disease about 95-

100% Milder clinical presentation Susceptible children with 72 hours

and possibly up to 120hrs after exposure

Varicella vaccine Live attenuated viral vaccine US:

Institutional settings Teachers Non-pregnant women of childbearing age (avoid pre

gnancy for 3 months afterwards) International travellers Health care workers Family members of immunocompromised patients

NOT needed for those with reliable hx of chickenpox

Varicella vaccine HK:

Epidemiology and burden largely unknown

? Cost-effectiveness of universal immunization

Selective immunization Healthcare workers

Varicella vaccine-specific contraindications Allergic reaction to neomycin, gelatin or pri

or dose Pregnancy Immunodeficiency or those on immunosup

pressive therapy On aspirin (stopped for 6 weeks) Moderate or severe acute illness Malignant neoplasms affecting bone marro

w or lymphatic systems

Meningitis- children killer?

Meningococcal, pneunococcal and hemophilus influenza type B

Meningococcal vaccine Quadrivalent polysaccharide vaccine

(A,C,Y, W-135) and monovalent polysaccharide vaccines, efficacy <100%

Men A vaccine in China (large outbreak in 1970s)

Meningococcal vaccines US: 33% serogroup B, 28% group C, 34

% group Y (1995-8) College students 0.6/100000 Freshmen in dorm 4.6/100000 Children 2-5yr 1.7/100000 Not cost-effective

Meningococcal vaccines UK: Growing burden of serogroup C in late 90s <1 yr: 31.5/100000 1-4 yr: 16/100000 Nov 1999, incorporated MenC conjugate va

ccine into routine infant immunization (3 doses for <2m, 2 doses of 5-12mo)

National campaign offering vaccine to everyone <18yr (1 dose)

Meningococcal vaccine for HK? 1995-97: 17 cases of infection (meningitis a

nd septicemia) reported to DH Incidence of 0.03-0.08/100000 81% local cases, 38% children <4 yrs 4 serogroup B, 2 group A, 2 nonB

Jan 2000 – July 2001 24 cases reported 79% local, same age distribution 8 serogroup W-135

Indication for use Outbreak control caused by strains wi

th a capsular group contained in the vaccine

High risk group: Complement deficiency Hyposplenia Travellers to highly endemic areas

Conjugated pneumococcal vaccine Heptavalent conjugated pneumococcal vac

cine trial involving >37000 children followed for 24 months found protective against both invasive disease (meningitis, pneumonia, septicemia) and acute otitis media Serotype-specific efficacy was 94% against inva

sive disease 85% against bacteremic pnuemonia

Licensed in Feb 2000 in US

Conjugated pneumococcal vaccine Heptavalent vaccine Serotypes (4, 6B, 9V, 14, 18C, 19F, 23F) In various sites of body (nasopharyng

eal, mucosal and invasive)

Should we use it in HK? Lack of documentation of disease bur

den Very few lab diagnosed bacteremia or

meningitis in HA hospital No pneumococcal disease in HK?

Haemophilus influenza type B Meningitis associated with high

mortality and morbidity in Europe and North America

Annual incidence: 22-109/100000 of age <5 yr

Annual incidence in HK: 2.67/100000 ? Cost effectiveness ? Combined vaccine

Combination vaccine Simplify administration and promote

compliance Technical difficulties and decreased i

mmunogenicity Whole cell DTP-Hib, DTaP-Hib, DTaP-

Hib-IPV, HepatitisB-Hib

DTaP (acellular pertussis vaccines) VS DTwP (whole-cell pertussis vaccine) DTwP is effective but well known for post-v

accination fever (48hr) and local reatogenicity (swelling and induration) of injection site

DTaP causing less adverse effects and as effective as, if not more effective than DTwP

Cost-effective? Combination vaccines in future?

The end

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Immunisation Update By Sindy Lee & Eva Wong 27 th March 2003.

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