Vaccines & Cold Chain

Classification Of Vaccines

NIS (National Immunization Schedule, India 2020-21)

• At Birth: BCG, OPV, Hep B
• 6 W: DPT₁, OPV₁, Hep B₁, HiB₁, Rota V₁, fIPV₁, PCV₁
• 10 W: DPT₂, OPV₂, Hep B₂, HiB₂, Rota V₂
• 14 W: DPT₃, OPV₃, Hep B₃, Rota V₃, fIPV₂, PCV₂, HIB₃
• 9 M: Measles₁/MR₁, Vitamin A (1 Lac IU), PCV_booster, JE_1Live
• Every 6 months: Vitamin A (2 Lacs IU) till 5 years
• 16–24 months: DPT_booster, OPV_booster, Measles₂/MR₂, JE_2Live
• 5 Years: DPT_booster
• 10 Years: TT
• 16 Years: TT
• Pregnancy: TT
• TT: Replaced with Td(tetanus diphtheria combination vaccine)
• Total Vit A given under NIS is 17 Lac IU

Contraindications

• Pregnancy: All live vaccines are C/I as it is an immuno-compromised state except yellow fever.
• Lactation: All vaccines are safe except yellow fever
• HIV: All live vaccines C/I 
• Symptomatic HIV+: All vaccines are C/I except MMR, Varicella, Zoster
• Asymptomatic HIV+: No C/I.
• Similarly, in a newborn infant, all live vaccines are contraindicated if the newborn is HIV positive except OPV & measles vaccine. BCG vaccine use is controversial in HIV +ve newborns. Ideally, it should not be given. 
• Prematurity &< 2 kg BW is a contraindication for Hepatitis B vaccine
• Epilepsy: C/I Pertussis.
• Cerebral Palsy: No C/I, as it is a non-progressive disease.

AEFIS (Adverse Events Following Immunization)

• Ideal recommended observation time after immunization of a child is 30 minutes. 
• Paralysis: OPV, paralysis is of 2 types 
  • VAPP (P₃) 
  • VDPV (cP₂)
• Hypersensitivity reaction & shock: Hep B
• TSS: Measles
• GBS: Killed Influenza/ Swine flu vaccine
• Intussusception: Rota V
• Febrile seizures: Measles
• Persistent crying & HHE (Hypotensive, Hypo-responsive episode): Pertussis
• Thrombocytopenia: MMR, Hep B

Lyophilized Vaccines/ Freeze Dried Vaccines

• They are in powdered form
• BCG: Reconstituted with normal saline 
• YF: Reconstituted with cold physiological saline
• JE: Reconstituted with phosphate buffer saline (PBS)
• HiB: Reconstituted with DPT vaccine or saline
• Measles and MMR: Reconstituted with distilled water/ sterile water
• In dry form they are highly stable but after mixing with diluent they are highly unstable and hence should be used within 4 hours of reconstitution

Vaccine Strains

Cold Chain

• It is the process of maintaining of the temperature of vaccine from point of manufacturing to point of administration

ILR (Ice Lined Refrigerator)

• Kept at PHC
• Vaccines can be stored for up to 1 month
• Minimum electricity required per day is 8 hours 
• If there is no electricity, it can maintain the temperature of all vaccine for 5 days 

Vaccine Carrier

• Used to transport from PHC to the site of immunization and sub-centers 
• It is a non-electronic instrument with 4 ice packs inside it
• Max 16-20 vaccine vials can be placed.
• It can maintain temp for 24-48 hrs. 

Fully Frozen Ice Pack 

• Smallest component of cold chain
• Used at immunization session level
• 2 vaccines are kept in two holes inside the ice pack
• Horizontal mark indicates water filling level. 

Dial Thermometer 

• Used to monitor the temperature of cold chains, especially at PHC inside ILR.
• Based on the principle of Thermocouple
• Temperature is monitored twice a day
• Alcohol stamp thermometer is more sensitive but dial thermometer is easier to use. 

Reverse Cold Chain

• Used in NPEP for transportation of Polio stool samples to lab at 2–8°C
• Collect stool samples from house of the person and send back to the lab where virus isolation and culture is done

Warm chain

• Synonym of kangaroo mother where a newborn is kept against the body of the mother to prevent neonatal hypothermia

Mission Indradhanush

• Aim: 100% immunization coverage of 7 vaccine preventable diseases by 2020.
• BCG, OPV, DPT, Measles, Hepatitis B.
• Further added: JE, IPV, Rota virus, MR, PCV, HiB

Switch Program

• tOPV: P₁, P₂, P₃ → bOPV: P₁, P₃ 
• National Switch Day: 25^th April 2016
• National Validation Day: 9^th May 2016

Vaccine Vial Monitor (VVM)

• Vaccine Vial Monitor 
• It has an outer blue circle, inner white square
• If temperature maintained properly, inner square always remain white
• If temperature is not maintained in 2-8 degrees, the inner white square starts to change in color. If the inner square is lighter than the outer circle, use the vaccine
• If the inner square same or darker than the circle, discard the vaccine
• According to WHO, Grade 1 and 2 can be used. Grade 3 and 4 should be discarded. 
• It is a marker of cold chain maintenance

Vaccine Vial Monitor (VVM)

• BCG
  • 0-80% 
  • 0% for pulmonary Tb
  • Median 50% (only against severe forms of Tb)
• Measles
  • >90% with 1 dose
  • >99% with 2 doses 
  • India has adopted 2 doses of measles vaccine strategy called AMMRS (Accelerated Measles Mortality Reduction Strategy)
• Rubella: >95% (Vaccine with the highest efficacy with single dose)

First Vaccine

• Smallpox vaccine (Developed by Edward Jenner)
• E. Jenner coined the term ‘Vaccination’
• Louis Pasteur coined the term ‘Vaccine,’ also developed Anthrax and Rabies vaccine

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