Vaccines are an essential component of preventive medicine, which is a critical part of public health. Knowledge of vaccines and their management is crucial for preventing the spread of infectious diseases and reducing the incidence of vaccine-preventable diseases.
In this blog, we’ll discuss vaccines and their classification, contraindications, AEFIS, cold chain, switch program and more. Keep reading.
Classification Of Vaccines
Polysaccharide & Glycoconjugate
NIS (National Immunization Schedule, India 2020-21)
TT: Replaced with Td(tetanus diphtheria combination vaccine)
Total Vit A given under NIS is 17 Lac IU
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.
During epidemic or post disaster: All vaccines are C/I except measles vaccine.
AEFIS (Adverse Events Following Immunization)
Ideal recommended observation time after immunization of a child is 30 minutes.
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
Exceptionally YF vaccine should be used within half an hour of reconstitution & JE vaccine with in 1 hour of reconstitution. If used beyond the given time, TSS due to S. Aureus contamination can lead to death of the child
mVA (Modified vaccinia ancara)
RTS, S (AS01) (World’s first & only licensed malaria vaccine).
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
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.
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
Synonym of kangaroo mother where a newborn is kept against the body of the mother to prevent neonatal hypothermia
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
tOPV: P1, P2, P3 → bOPV: P1, P3
National Switch Day: 25th April 2016
National Validation Day: 9th 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)
0% for pulmonary Tb
Median 50% (only against severe forms of Tb)
>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)
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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