Vaccine

Aka: Vaccine, Vaccination, Immunization, Vaccine Safety, Immunization Contraindication, Vaccine Adverse Event Reporting System, VAERS

1. See Also
   1. Primary Series (Pediatric Vaccination)
   2. Adult Immunization
   3. Immunization Status Unknown
   4. Vaccines in Immunocompromised Patients
   5. Immunization in HIV
   6. Immunization in Pregnancy
2. Background
   1. Vaccination was described by Edward Jenner in England, 1796
      1. Demonstrated Cowpox innoculation prevented Smallpox
      2. Vaccination is derived from vacca (cow)
   2. Vaccination is based on the development of active Immunity
      1. Active Immunity is a function of the adaptive immune sytem and occurs after recovering from an illness
      2. Vaccination exposes patients to an attenuated microbe or its Antigens and results in similar Immunity
      3. Vaccines offer Immunity without the risk of mortality or morbidity associated with the natural infection
   3. Allergen Immunotherapy
      1. Immunotherapy with allergan extracts is based on the same active Immunity process as for Vaccination
   4. Passive Immunity, in contrast, relies on an infusion of antibodies from others
      1. Mothers (trans-placental lasting for the first 3-6 months, Breast Feeding)
      2. Intravenous Gamma Globulin (IVIG) from pooled donors
      3. Specific antibodies
3. Mechanism
   1. Primary immune response
      1. Onset in the first week of exposure to infection or Immunization
      2. IgM Antibody to microbe peaks after the first 2 weeks and then gradually decreases
   2. Secondary immune response
      1. Memory cells (B Cell type) form after the primary immune response
      2. IgG high affinity Antibody to microbe increases to high, sustained levels on second Antigen exposure
4. Types
   1. Live Attenuated Vaccine
      1. Highly effective, resulting in prolonged or even life-long Immunity
      2. Contains live, but attenuated organism from which Immunocompromised patients may become ill
   2. Killed Bacteria Vaccine
      1. Shorter duration of protection than with Live Attenuated Vaccine
      2. Vaccine contains either whole killed Bacteria or its subunit Antigens (e.g. toxins, DNA)
   3. Bacterial Polysaccharide Vaccine
      1. Bacterial Polysaccharide (e.g. pneumococcus) is conjugated with a carrier protein (e.g. toxoid molecule)
      2. Carrier protein conjugation allows for T Helper Cell Activation
   4. Toxoid Vaccine
      1. Attenuated Bacterial exotoxins (e.g. Tetanus Toxoid) stimulate active Immunity against the organism's toxins
5. Precautions: Safety
   1. Vaccines are safe
      1. Serious Allergic Reaction occur in less than 4 in one million with DTaP Vaccine, MMR Vaccine, Varicella Vaccine
      2. Most pediatric Vaccines do not contain thimerosol (and thimerosol)
      3. Of the 6000 daily Antigen exposures daily, a full Primary Series only exposes children to a total of 150 Antigens
   2. Vaccines prevent life threatening illness
      1. Tetanus will kill one child in 10 who contract the infection
      2. Measles will kill one child in 1000 who contract the infection
      3. Varicella will kill one older child in 100,000 who contract the infection
   3. Undervaccination puts community health at risk
      1. Take every opportunity to catch up Vaccinations
      2. Undervaccination associated with the 2020 Coronavirus pandemic is a significant risk for other outbreaks
         1. Santoli (2020) MMWR Morb Mortal Wkly Rep 69:591-3 [PubMed]
            1. https://www.cdc.gov/mmwr/volumes/69/wr/mm6919e2.htm?s_cid=mm6919e2_w
      3. Undervaccination has been associated with resurgence of Measles
         1. Gahr (2014) Pediatrics 134(1): e220-8 +PMID:24913790 [PubMed]
      4. Adolescents frequently miss Vaccines with significant preventive potential
         1. HPV Vaccine (Gardasil Vaccine)
         2. Meningococcal Vaccine (Menactra, Menveo)
         3. Tdap Vaccine (Adacel)
         4. Influenza Vaccine
   4. Vaccine refusal
      1. Listen to concerns without minimizing concerns
      2. Explain risks and benefits
      3. Consider asking parents to sign a "Refusal to Vaccinate"
      4. Consider applying appropriate billing codes
         1. V64.05 Vaccine refusal by Caregiver
         2. V64.07 Vaccine refusal for religious reasons
   5. Avoid prophylactic Analgesics and antipyretics at the time of Immunization (per CDC)
      1. Antipyretics do not reduce the risk of Febrile Seizure
      2. Risk of decreased immunogenic response to Vaccination
         1. Prymula (2009) Lancet 374(9698): 1339-50 [PubMed]
   6. Vaccine Adverse Event Reporting System (VAERS)
      1. Vaccinations are closely monitored for adverse events in U.S. via VAERS system
      2. Vaccination adverse events may be reported by anyone including parent and patient self-report
         1. Individual reports may be inaccurate and do not reflect causality
         2. CDC and FDA monitor the data to identify patterns and trends with specific Vaccinations
      3. VAERS Website
         1. https://vaers.hhs.gov/
   7. References
      1. (2015) Presc Lett 22(3): 13
6. Contraindications: Vaccination
   1. True contraindications to Vaccination
      1. Current moderate to severe illness
      2. Anaphylaxis to Vaccine or Vaccine constituent (see below)
         1. Anaphylaxis to Vaccination is rare (<1 in one million doses)
         2. Obtain immediate type allergy Skin Testing if Vaccination is suspected for severe allergy or Anaphylaxis
   2. Conditions that do not contraindicate Vaccine
      1. Moderate inflammation at prior Immunization site
      2. Moderate fever following prior Vaccination
      3. Current antibiotic usage
      4. Recovering from illness or recent exposure to illness
      5. Prematurity (no change in dosage)
      6. Unvaccinated household contact
      7. Pregnancy of household contact
7. Preparations
   1. Primary Series Vaccines
      1. See Immunization Schedule in Children
      2. HaemophilusInfluenzae type B (Hib Vaccine)
      3. Inactivated Polio Vaccine (EIPV)
      4. Pneumococcal Conjugate Vaccine (PCV, Prevnar)
      5. Measles Mumps Rubella Vaccine (MMR)
      6. Varicella Vaccine
      7. Rotavirus Vaccine
      8. DiphtheriaTetanus acellular Pertusis (DTaP Vaccine)
      9. Hepatitis B Vaccine (HepB Vaccine)
      10. Hepatitis A Vaccine
   2. Teen Vaccines
      1. Tetanus Diptheria acellular Pertussis (Tdap Vaccine)
      2. Meningococcal Conjugate Vaccine (MCV4)
      3. Human Papillomavirus Vaccine
   3. Adult Vaccines
      1. Tetanus Diptheria Vaccine (Td Vaccine)
      2. Tetanus Diptheria Acellular Pertussis Vaccine (Tdap, Adacel, Boostrix)
      3. Human Papillomavirus Vaccine
   4. Older adult Vaccines
      1. Pneumovax 23 Vaccine
      2. Shingles Vaccine
   5. Annual Vaccines
      1. Influenza Vaccine
8. Precautions: Vaccine Additives
   1. Potential allergans for those with known Anaphylaxis to these agents
   2. Neomycin
      1. Varicella Vaccine
      2. Measles Mumps Rubella Vaccine (MMR Vaccine)
      3. Inactivated Polio Vaccine
   3. Gelatin
      1. Varicella
      2. Measles Mumps Rubella Vaccine (MMR Vaccine)
   4. Egg protein
      1. Inactivated Influenza Vaccine (use egg-free trivalent Inactivated Influenza Vaccine instead)
      2. Egg allergy is not a contraindication to Measles Mumps Rubella Vaccine (MMR Vaccine)
   5. Thimerisal
      1. Preservative in Vaccinations used since 1930s
      2. Contains small amount of Mercury, but no association with any neurologic disorder including Autism
      3. Removed from all Vaccinations in U.S. except for multi-dose Inactivated Influenza Vaccine
   6. Latex
      1. Infarix (DTaP Vaccine)
      2. Menomune, Bexsero (Meningococcal Vaccine)
      3. Rotarix (Rotavirus Vaccine oral applicator)
9. Precautions: Maintaining Vaccine efficacy
   1. Maintain the cold chain prior to Vaccine administration
      1. Most Vaccines must be maintained in a tightly Temperature controlled refrigerator to ensure Vaccine efficacy
   2. Consider a back-up generator to protect Vaccines if power fails
   3. Manufacturers can give guidance if vaccine Temperatures varied from those recommended
   4. Use a refrigerator designed for Vaccines
   5. Monitor refrigerator Temperature twice daily or more with buffered probe Thermometer (e.g. glycol-encased)
      1. Continuous monitoring and automatic recording is preferred
      2. Thermometer ideally alarms when Temperature falls out of safe range
   6. Keep Vaccines on the middle of the shelves (not in the door or along the back wall) to maintain consistent Temperature
   7. Water bottles or freezer packs can help stabilize the Temperature (but do not store food with Vaccines)
   8. References
      1. (2012) Presc Lett 19(12): 70
10. Resources
    1. WHO Vaccine Safety
       1. https://www.who.int/vaccine_safety/initiative/tools/vaccinfosheets/en/
    2. CDC Vaccine Safety
       1. https://www.cdc.gov/vaccinesafety/index.html
    3. Healthy Children (AAP) Vaccine Safety
       1. https://www.healthychildren.org/English/safety-prevention/immunizations/Pages/Vaccine-Safety-The-Facts.aspx
    4. CDC Immunization Schedules
       1. https://www.cdc.gov/vaccines/schedules/
11. References
    1. Mahmoudi (2014) Immunology Made Ridiculously Simple, MedMaster, Miami, FL
    2. Spencer (2017) Am Fam Physician 95(12): 786-94 [PubMed]