An alternative vaccination schedule is a vaccination schedule differing from the schedule endorsed by the Advisory Committee on Immunization Practices (ACIP).[1] These schedules may be either written or ad hoc, and have not been tested for their safety or efficacy.[2][3] Proponents of such schedules aim to reduce the risk of adverse effects they believe to be caused by vaccine components, such as "immune system overload" that is argued to be caused by exposure to multiple antigens.[4] Parents who adopt these schedules tend to do so because they are concerned about the potential risks of vaccination, rather than because they are unaware of the significance of vaccination's benefits.[5] However, use of alternative vaccination schedules is associated with an increased risk of vaccine-preventable disease.[6]


Contrary to the claims made by some advocates of alternative vaccine schedules, there is no scientific evidence for the existence of "immune system overload", and according to the UK National Health Service the idea is a "myth".[7][8] In addition, the amount of chemicals in vaccines such as aluminum and formaldehyde is much lower than natural exposure levels.[4] Intentional deviation from the ACIP's schedule leaves children vulnerable to infection and increases the likelihood of outbreaks of vaccine-preventable diseases.[9] These schedules also increase the chances of infection among individuals who could not be vaccinated for medical reasons, because they were too young, or who did not develop a sufficient immunologic response to the vaccine.[10][11]

After one of the most notorious outbreaks of measles in the United States, in California, legislation was passed to make vaccination mandatory, as alternative vaccine scheduling and/or avoidance had been prevalent before the outbreak.[12]


An increasing number of children are undervaccinated, of whom an estimated 13% or more are believed to be so because of parental choice.[13] One survey, published in Vaccine, found that 9.4% of parents in King County, Washington used an alternative vaccine schedule,[1] while another survey found that more than 1 out of 10 parents of children aged between 6 months and 6 years used an alternative vaccine schedule.[6] In a 2011 survey of Washington State pediatricians, 77% of them reported that their patients "sometimes or frequently" asked for alternative vaccination schedules.[14] The same survey found that 61% of pediatricians were comfortable with using such a schedule if a parent asked for it.[14] A 2012 survey found that the percentage of shot-limiting children—defined as children who received no more than two vaccines per visit between their birth and the age of nine months—had increased from 2.5% to 9.5% in Portland, Oregon.[15][16] Research on well-off American families suggests that even parents who are ostensibly pro-vaccine can be misled by disinformation, and this can lead them to delay having their children vaccinated, and to tolerate such delay in others.[17]


Among the most prominent proponents of alternative vaccination schedules is notable pediatrician and vaccine critic Robert Sears.[15][18] Sears has been criticized by vaccine expert Paul Offit for what Offit states is Sears' "misrepresentation of vaccine science."[19] Offit argues that Sears' alternative vaccination schedules present a public health risk, in that Sear's alternative vaccination schedules require a larger number of visits to the doctors office for parents - and unvaccinated children can acquire transmissible diseases while waiting in doctors offices'.[19] Furthermore, increasing the time before a child receives a vaccine will increase the time in which that child is vulnerable to contracting preventable diseases.[19] Additionally, spreading out vaccination shots does not decrease a child's pain or anxiety related to the shot: in fact, increasing a child's total amount of doctor visits for vaccination shots (by insisting upon a single shot per visit) may increase that child's needle phobia, according to Dr. Offit.[20] Overall, Sears' alternative vaccination schedules are likely to decrease immunization rates by reducing vaccine timeliness.[19] Notably, Sears has responded to Offit's critique by conceding many of his original positions - in other words, Sears has since stated that he is in favour of the conventional vaccine schedule, and that many of his original positions (e.g., that thimerosal causes autism) are not supported by evidence. [21] Likewise, the American Academy of Pediatricians has stated that no alternative vaccine schedules have been found to provide better safety or efficacy than the recommended vaccination schedule.[22]

In June 2018, the Medical Board of California placed Sears on probation for improperly granting a medical exemption from all future vaccines to a two-year-old child without obtaining any of the child's medical records, including which vaccines the child had received to date.[23][24][25]

Types of schedules

A 2016 study identified five different types of alternative vaccine schedules: Sears' schedule, a shot-limiting schedule, selective delaying or refusal, making vaccine decisions visit-by-visit, or refusing all vaccines.[26] Regardless of the type of alternative schedule used, skipping or delaying recommended vaccines has been shown to result in an increased risk of contracting and spreading vaccine-preventable diseases.[6]

See also


  1. ^ a b Opel, Douglas J.; Banerjee, Ashmita; Taylor, James A. (October 2013). "Use of alternative childhood immunization schedules in King County, Washington, USA". Vaccine. 31 (42): 4699–4701. doi:10.1016/j.vaccine.2013.08.036. PMID 23981431.
  2. ^ Opel, Douglas J.; Marcuse, Edgar K. (1 March 2013). "The Enigma of Alternative Childhood Immunization Schedules". JAMA Pediatrics. 167 (3): 304–5. doi:10.1001/jamapediatrics.2013.786. PMID 23338852.
  3. ^ Boom, Julie; Cunningham, Rachel (2014). Understanding and Managing Vaccine Concerns. Springer. pp. 8–9. ISBN 9783319075631.
  4. ^ a b Jackson, Michael L. (April 2013). "Challenges in comparing the safety of different vaccination schedules". Vaccine. 31 (17): 2126–2129. doi:10.1016/j.vaccine.2013.02.054. PMID 23470238.
  5. ^ Healy, C. Mary; Montesinos, Diana P.; Middleman, Amy B. (January 2014). "Parent and provider perspectives on immunization: Are providers overestimating parental concerns?". Vaccine. 32 (5): 579–584. doi:10.1016/j.vaccine.2013.11.076. PMID 24315883.
  6. ^ a b c Dempsey, AF; Schaffer, S; Singer, D; Butchart, A; Davis, M; Freed, GL (November 2011). "Alternative vaccination schedule preferences among parents of young children". Pediatrics. 128 (5): 848–56. doi:10.1542/peds.2011-0400. PMID 21969290.
  7. ^ "Myths about children's vaccines". NHS. 7 April 2016.
  8. ^ HickokMar. 6, Kimberly; 2018; Am, 11:00 (2018-03-06). "Vaccines won't overload your child's immune system—or increase their risk of other infections". Science | AAAS. Retrieved 2018-12-30.CS1 maint: numeric names: authors list (link)
  9. ^ Nadeau, Jessica A.; Bednarczyk, Robert A.; Masawi, Munyaradzi R.; Meldrum, Megan D.; Santilli, Loretta; Zansky, Shelley M.; Blog, Debra S.; Birkhead, Guthrie S.; McNutt, Louise-Anne (January 2015). "Vaccinating My Way—Use of Alternative Vaccination Schedules in New York State". The Journal of Pediatrics. 166 (1): 151–156.e1. doi:10.1016/j.jpeds.2014.09.013. PMID 25444525.
  10. ^ Wheeler, Marissa; Buttenheim, Alison M (27 October 2014). "Parental vaccine concerns, information source, and choice of alternative immunization schedules". Human Vaccines & Immunotherapeutics. 9 (8): 1782–1789. doi:10.4161/hv.25959. PMC 3906282. PMID 23900266.
  11. ^ Siddiqui, Mariam; Salmon, Daniel A; Omer, Saad B (1 December 2013). "Epidemiology of vaccine hesitancy in the United States". Human Vaccines & Immunotherapeutics. 9 (12): 2643–2648. doi:10.4161/hv.27243. PMC 4162046. PMID 24247148.
  12. ^ Hussain A, Ali S, Ahmed M, Hussain S (2018). "The Anti-vaccination Movement: A Regression in Modern Medicine". Cureus (Review). 10 (7): e2919. doi:10.7759/cureus.2919. PMC 6122668. PMID 30186724.
  13. ^ Glanz, Jason M.; Newcomer, Sophia R.; Narwaney, Komal J.; Hambidge, Simon J.; Daley, Matthew F.; Wagner, Nicole M.; McClure, David L.; Xu, Stan; Rowhani-Rahbar, Ali; Lee, Grace M.; Nelson, Jennifer C.; Donahue, James G.; Naleway, Allison L.; Nordin, James D.; Lugg, Marlene M.; Weintraub, Eric S. (1 March 2013). "A Population-Based Cohort Study of Undervaccination in 8 Managed Care Organizations Across the United States". JAMA Pediatrics. 167 (3): 274–81. doi:10.1001/jamapediatrics.2013.502. PMID 23338829. In our cohort, we also estimate that approximately 13% of children were undervaccinated because of parental choice, which aligns with other published estimates of 10% to 25% from cross-sectional survey and population-based ecologic studies. However, this likely represents an underestimate of the true prevalence of intentional undervaccination and alternative vaccination schedules.
  14. ^ a b Wightman, A; Opel, DJ; Marcuse, EK; Taylor, JA (December 2011). "Washington State pediatricians' attitudes toward alternative childhood immunization schedules". Pediatrics. 128 (6): 1094–9. doi:10.1542/peds.2011-0666. PMC 3387893. PMID 22123877.
  15. ^ a b Robison, S. G.; Groom, H.; Young, C. (18 June 2012). "Frequency of Alternative Immunization Schedule Use in a Metropolitan Area". Pediatrics. 130 (1): 32–38. doi:10.1542/peds.2011-3154. PMID 22711719.
  16. ^ Seaman, Andrew M. (18 June 2012). "More Oregon kids on "alternative" vaccine schedules". Reuters. Retrieved 7 February 2015.
  17. ^ Wang, Eileen; Baras, Yelena; Buttenheim, Alison M. (November 2015). ""Everybody just wants to do what's best for their child": Understanding how pro-vaccine parents can support a culture of vaccine hesitancy". Vaccine. 33 (48): 6703–6709. doi:10.1016/j.vaccine.2015.10.090. PMC 5554443. PMID 26518397.
  18. ^ Poland, Gregory A.; Jacobson, Robert M. (2012-08-01). "The clinician's guide to the anti-vaccinationists' galaxy". Human Immunology. 73 (8): 859–866. doi:10.1016/j.humimm.2012.03.014. ISSN 0198-8859. PMID 22504410.
  19. ^ a b c d Offit, Paul A.; Moser, C. A. (1 January 2009). "The Problem With Dr Bob's Alternative Vaccine Schedule". Pediatrics. 123 (1): e164–e169. doi:10.1542/peds.2008-2189. PMID 19117838.
  20. ^ "Alternative vaccine schedule can be as risky as no vaccines". Healthy Debate. Retrieved 2021-02-28.
  21. ^ "Paul Offit Takes On Robert Sears | Science-Based Medicine". 2009-01-07. Retrieved 2021-02-28.
  22. ^ Edwards, Kathryn M.; Hackell, Jesse M.; The Committee on Infectious Diseases, The Committee on Practice and Ambulatory Medicine (2016-09-01). "Countering Vaccine Hesitancy". Pediatrics. 138 (3). doi:10.1542/peds.2016-2146. ISSN 0031-4005. PMID 27573088.
  23. ^
  24. ^ Karlamangla, Soumya. "California doctor critical of vaccines is punished for exempting 2-year-old boy from all childhood immunizations". Retrieved 2018-12-30.
  25. ^ "Dr. Bob Sears, renowned vaccine skeptic, placed on probation for exempting child from all vaccinations". Orange County Register. 2018-06-29. Retrieved 2018-12-30.
  26. ^ Saada, A.; Lieu, T. A.; Morain, S. R.; Zikmund-Fisher, B. J.; Wittenberg, E. (7 September 2014). "Parents' Choices and Rationales for Alternative Vaccination Schedules: A Qualitative Study". Clinical Pediatrics. 54 (3): 236–243. doi:10.1177/0009922814548838. PMID 25200366.

Further reading