The Science of Vaccines: Addressing Common Concerns Paul A. Offit Division of Infectious Diseases Children s Hospital of Philadelphia Perelman School of Medicine The University of Pennsylvania
Are vaccines safe?
Vaccine Safety Issues OPV and polio Gelatin and latex allergies Measles vaccine and thrombocytopenia Squalene-adjuvanted flu vaccine and narcolepsy Yellow fever vaccine and viscerotropic disease
Isn t it better to be naturally infected than immunized?
Can so many vaccines given at once overwhelme a baby s immune system?
Times have changed # of shots by 2 # shots at Year Vaccines years of age one time 1900 Smallpox 1 1
Times have changed # of shots by 2 # shots at Year Vaccines years of age one time 1980 DTwP 5 2 Polio (OPV) MMR
Times have changed # of inocs by 2 # of inocs Year Vaccines years of age one time 2017 DTaP 26 5 Polio (IPV) MMR Varicella Pneumococcal (conj) Hepatitis A, B Hib Influenza Rotavirus
Number of antigens in vaccines Year Vaccine # of antigens 1900 Smallpox 200
Number of antigens in vaccines Year Vaccine # of antigens 1980 Diphtheria 1 Tetanus 1 Pertussis (wc) ~3000 Polio (OPV) 15 Measles 10 Mumps 9 Rubella 5 Total ~3041
Number of antigens in vaccines Year Vaccine # of antigens 2017 Diphtheria 1 Tetanus 1 Pertussis (ac) 2-5 Polio (IPV) 15 MMR 24 Hib 2 Varicella 69 Hepatitis A, B 5 Rotavirus 11-15 Influenza 12-14 Pneumococcus 8 Total 150-159
Are infants too young to be vaccinated? From birth, infants are challenged by bacteria in the environment (colonizing bacteria on intestines, skin, and throat; bacteria inhaled on dust). Vigorous siga responses within the first week of life keeps colonizing bacteria from invading.
Are infants too young to be vaccinated? Excellent immune responses to HBV and BCG vaccines given at birth. About 95% of infants will develop protective immune responses to HBV, Hib, DTaP, polio, and pneumococcal vaccines by 6 months of age. Need to be fully immunized against certain infections (Hib, pertussis, pneumococcus) by 6 months of age.
Do vaccines cause autism?
Wakefield, A.J., et al. Lancet 351: 637-641, 1998
MMR-Autism: Scientific Studies I Taylor, B, et al. Lancet 1999;351:2026-29 Dales L, et al. JAMA 2001;285:1183-85 Kaye JA, et al. Brit Med J 2001;322:460-3 Madsen KM, et al. N Engl J Med 2002;347:1477-82 Peltola H, et al. Lancet 1998;351:1327-8.
MMR-Autism: Scientific Studies II Makela A, et al. Pediatrics 2002;110:957-63 DeStefano R, et al. Pediatrics 2004;113:259-66 Farrington CP, et al. Vaccine 2001;19:3632-5 Fombonne E, et al. Pediatrics 2001;108:e58 Taylor, B, et al. British Med J 2002;324:393-6
Impact of Wakefield paper Hospitalizations and deaths in the United Kingdom and Ireland Parents of more than 125,000 children in US choose not to vaccinate outbreaks in US Current outbreaks in the European region causing 35 deaths and outbreaks in the US in 2014, 2015, and 2017.
Why does the package insert for the DTaP vaccine state that it has been associated with autism?
Why do vaccines still contain mercury, a known toxin?
Preservatives Required for use in most vaccines since the 1930s Consequence of several events that occurred in the early 1900s with multi-dose vials (S. aureus contamination leading to local abscesses, systemic infections, death) Thimerosal (ethylmercury) was the most commonly used preservative
Mercury in the environment Hg is part of the earth s crust Released into the environment by burning coal, volcanoes and rock erosion Converted to organic mercury (methylhg) by bacteria Toxic to CNS at high quantities
Breast milk contains methylhg Breast milk contains 1.4-1.7 micrograms of methylmercury per liter. Levels similar in both developed and developing countries. Abadin et al. Toxicol Ind Health 1997;13:495-517 Ramirez et al. Pediatrics 2000;106:774-781.
Breast milk contains methyl Hg If you assume that babies consume 2-3 ounces per pound per day (or 150-200 ml per kg per day), then babies at the 50 th percentile for weight would ingest 360ug of methylhg during the first 6 months of life. Multi-dose vials of influenza vaccine contain 25ug of ethylhg (15-fold less than breast milk).
Thimerosal-Autism: Scientific studies Hviid A, et al. JAMA 2003;290:1763-66 Andrews N, et al. Pediatrics 2004;114:584-91 Herron J. Pediatrics 2004;114:577-83 Verstraeten T, et al. Pediatrics 2003;112:1039-48 Barbaresi W, et al. Arc Ped Ado Med 2005;159:37-44 Schecter R, et al. Arch Gen Psychiatry 2008;65:19-24
I ve been told that some vaccines are made from aborted fetuses. Is that true?
Albert Sabin (left) and Jonas Salk
Primary monkey kidney cells
SV40
SV40 virus caused cancer in experimental animals
Human fetal cells Derived from two elective abortions performed in the early 1960s. One in Sweden, which generated the WI38 cell line and the other in England, which generated the MRC5 cell line. The hepatitis A, rubella, varicella, and one of the rabies vaccines are made using these cells.
Why should I trust any product that makes money for pharmaceutical companies?
Vaccine Safety DataLink Established in 1990. Linked, computerized medical records from 9 managed care organizations. Represents about 7 million people, 500,000 of whom are children. Allows CDC to quickly determine whether a new vaccine has a particular side effect.
Can I use an alternative vaccine schedule?
The alternative schedule claims to reduce the stress of too many shots given at once
Are more shots more stressful? Study showing that two shots are not more likely to induce cortisol (as a marker for stress) than one shot. Ramsay DS, Lewis M. Developmental changes in infant cortisol and behavioral response to inoculation. Child Development 1994;65;1491-1502.
Why do some vaccines contain formaldehyde, a chemical used by morticians to preserve dead bodies?
Formaldehyde Inactivating agent for polio vaccine and others, less than 0.1 mg per dose. Essential intermediate in human metabolism; required for synthesis of thymidine, purines, and amino acids. All humans have about 2.5 ug/ml of blood.
Formaldehyde Assuming an average weight of a 2-month old of 5 kg and an average blood volume of 85 ml/kg then total quantity of formaldehyde circulating is about 1.1 mg. Therefore, 2-month old will have a quantity of formaldehyde in the circulation about 10 times greater than that contained in a vaccine.
Why are some vaccines mandated? The government shouldn t decide how I choose to raise my children.