immunization in special situations

Basics of immunization and IMMUNIZATION IN SPECIAL SITUATIONS

Dr.Nupur SinhaDept. Of PardiatricsLourdes HospitalKochi

Immunization schedules

Some definitions

• Vaccination: Process of inoculating the vaccine or the antigen

• Immunisation: Process of inducing immune response, humoral or cell mediated.

• Seroconversion: Change from antibody negative state to antibody positive state.

• Seroprotection: The state of protection (from disease) due to presence of humoral immunity or antibody detectable in serum

Types of vaccines• Live attenuated bacterial- BCG, Ty 21 a• Live attenuated viral – OPV, MEASLES, MMR,

VARICELLA• Killed or inactivated bacteria – DTPw• Killed or inactivated virus – IPV, RABIES, HAV• Toxoid – DT, TT• Capsular polysaccharide – Hib, PNEUMO, MENINGO• Viral subunit - HBsAg• Bacterial capsular polysaccharide –S.Typhi(Vi), Hib,

MENINGOCOCCAL, PNEUMOCOCCAL, ACELLULAR PERTUSSIS

Cold chain• Cold Chain is a system of storing and transporting

vaccine at the recommended temperature range from the point of manufacture to point of use.

• Vital link in immunisation• If not maintained, vaccine efficacy will grossly suffer• Safe temp. zone – mandatory to maintain potency• Safe zone for short term storage (1-2 months)is 2-8 deg

C. For long term storage –20 degC is used only for BCG,OPV,Measles/MMR

• The T series of vaccine(DPT,DT,TT),typhoid Vi,Hep B should not be frozen as once frozen the aluminium salts used as adjuvant will be desiccated and will act as irritantsterile abcess

• In order to provide potent and effective vaccine to the beneficiaries a vast cold chain infrastructure is required, which should have a network of Vaccine Stores, Walk-in-coolers (WIC), Walk-in-freezers (WIF), Deep Freezers (DF), Ice lined Refrigerators (ILR), Refrigerated trucks, Vaccine vans, Cold boxes, Vaccine carriers and icepacks from national level to states up to the out reach sessions.

• The cold chain system and vaccine flow in the country:- The vaccines are transported from the manufacturer through air transport under the temperature range of 2-8oC to the primary vaccine stores (GMSDs/State head quarter).

VACCINE VIAL MONITORS

• VVM is time and temperature sensitive coloured label.

• Consists of temperature sensitive material.• Changes colour gradually on being exposed to heat.• Corresponds to heat induced damage to vaccine

inside the vial.• Do not give information about cold injury• Especially used for OPV which is most thermo labile

vaccine.

Special situations

Immunization in preterm/low birth weight infants

• All vaccines as per schedule irrespective of birth weight or POG.

• According to chronological age• BCG/OPV at time of discharge• Hepatitis B after ≥ 2kg weight.• In < 2kg babies delay for one month after birth• PCV, rotavirus, influenza if possible

Hepatitis B positive mother

• ≥ 2kg baby: Hep B vaccine + HBIG within 12 hours of birth. Followed by 2 doses at 1, 6 months.

• < 2kg baby: Hep B vaccine + HBIG within 12 hours of birth. Followed by 3 more doses at 1, 2, 6 months.

• If HBIG not available/affordable –Hep B vaccine at 0, 1, and 2 mnths, additional dose bet 9-12 months.

Immunocompromised individual

• Severe immunodeficiency- all live vaccines contraindicated

• Inactivated vaccines –higher dose, greater number of dose of Hep B.

• Check antibody titres.(>10IU)• Regular boosters if needed• Contaminated wounds- TIG with TT even if 3 doses of

TT received in past.• Pneumococcal, varicella, hepatitis A, influenza vaccine

recommended

Household contacts of Immunocompromised

• Should not receive transmissible vaccines- OPV

• Non transmissible vaccines –varicella, MMR are safe

• Should be fully immunized- varicella, influenza

IMMUNODEFICIENCIES

• Severe B cell immunodeficiencyLive vaccines contraindicatedInactivated vaccines are ineffective

• Less severe B cell immunodeficiencyOnly OPV contraindicated

• Severe T cell immunodeficiencyLive vaccines contraindicatedAll vaccines ineffective

Children receiving corticosteroids/chemotherapy/radiotherapy

• Live vaccine contraindicated if1. High dose oral/iv corticosteroids(20mg/day in

children weighing >10kg or >2mg/kg/day)2. Duration> 2weeks• Can be administered if1. Low dose steroids2. Alternate day therapy3. Inhaled or topical steroids4. ≥ 4weeks after stopping steroids.

• Other immunosuppressive therapy: avoid live vaccines.

• Chemo /radiotherapy: avoid live vaccines during therapy and upto 3 months after stopping therapy.

• Asplenia /hyposplenia: vaccination with pneumococcal Hib, meningococal + all routine live and inactivated vaccines.

• Planned splenectomy: vaccination initiated 2 weeks prior to splenectomy.

• Complement deficiencyAll vaccines safePneumo, Hib, meningococcal vacc indicated

• Chronic granulomatous diseaseLive vaccines contraindicatedOther vaccines safe and effectiveYES if CD4 count>200(≥15%)

HIV INFECTIONVACCINE ASYMPTOMATIC SYMPTOMATIC

BCG YES NO

DTwP/DTaP/TT/Tdap YES YES

IPV/OPV IPV, OPV if IPV not affordable

IPV, OPV if IPV not affordable

Measles vaccine YES YES if CD4 count>200(≥15%)

MMR YES YES if CD4 count>200(≥15%)

Hepatitis B YES YES, 4 doses ,double dose, check seroconversion, boosters

Hib YES YES

VACCINE ASYMPTOMATIC SYMPTOMATIC

PCV & PPV23 YES YES

Inactivated influenza vaccine

YES YES

Rotavirus Insufficient data Insufficient data

Hepatitis A vaccine YES YES, check seroconversion, boosters

Varicella vaccine YES YES if CD4 count>200(≥15%)

Vi typhoid vacc YES YES if CD4 count>200(≥15%)

HPV YES YES

TRANSPLANT RECIPIENTS

• Hematopoietic stem cell transplant recipientLoose all memory cellsAre like unimmunizedKilled vaccines started 12 months post transplantLive vaccines 24 months post transplant if recipient is

immunocompetentInfluenza vaccine given pretransplant, restarted 6

months post transplant

• Contacts of HSCT- varicella and influenza. Completed 6 weeks before transplant date.

• Solid organ transplant recipientLive vaccines completed 2 weeks prior to transplantPost transplant- live vaccines CICheck seroconversionRecommence inactivated vaccines- 6 months post

transplant (immunosuppression lowered)Boosters for Hep A and BAnnual influenza vaccineContacts- varicella and influenza

IVIG/PLASMA/PRBC/WHOLE BLOOD RECIPIENTS

• Inactivated vaccines- safe• After receiving antibody containing products-

Live vaccines avoided for 3 months.• Antibody products avoided for 2 weeks after

live vaccine• If immunization outside prescribed period

occurs- check seroconversion, revaccination• OPV not contraindicated

UNIMMUNIZED CHILDVISIT SUGGESTED VACCINES

First Measles/MMR if >12mthsDTwP1/DTaP1/Tdap if ≥7yearsOPV1/IPV1 (if < 5years)Hib1 (if < 5 years)Hep B1

Second- after 1 month of 1st visit BCG(if < 5years)DTwP2/DTaP2/Td if ≥7yearsOPV2Hib 2Hep B2

Third –after 2 month of 1st visit OPV3/IPV2MMR if >12 monthsTyphoid if > 2years

Fourth –after 6 month of 1st visit DTwP3/DTaP3/Td if ≥7yearsOPV4/IPV3Hep B3

IAP recommendations for adolescent travellers

vaccine Place of travel doseMeningococcal vaccine USA/UK/endemic areas

Saudi Arabia and Africa.2 doses 4-8 weeks apart

Yellow fever Yellow fever endemic zones

10 days before travel

Oral cholera vaccine Endemic area or an outbreak

2 doses 1 week apart

Japanese B encephalitis Endemic areas Single dose(upto 15 years)

Rabies vaccine(pre exposure prophylaxis)

For adolescents going on trekking

0,7,28

Children with chronic illness• Live vaccines are safe• Other recommended vaccines:

PneumococcalHep AVaricella InfluenzaRotavirus

• Immunogenicity, efficacy, duration of protection- low

• More doses- Hep B, Boosters

IMMUNIZATION DURING ILLNESS

• Postponed only during serious illness• Vaccination encouraged during minor illness : mild

diarrhea, URTI INTERCHANGEABILITY OF BRANDS• Brands of Hib, Hep B and Hep A safely interchanged• Same brand preferred for DTaP• If previous brand not known/not available- any

brand used• Vaccination should not be delayed/cancelled due

non availability of brand.