Robert William Sears, known as Dr. Bob, is an American pediatrician from Capistrano Beach, California, noted for his unorthodox and dangerous views on childhood vaccination. While Sears has acknowledged the efficacy of vaccines, he has also proposed alternative vaccination schedules that depart from accepted medical recommendations. Additionally, Sears has falsely suggested vaccine preservatives and adjuvants (such as thimerosal and aluminum) are unsafe, falsely linked vaccines to autism, and promoted various discredited, unproven, and potentially dangerous alternative autism treatments and prophylactics (including chelation therapy and hyperbaric oxygen therapy). His proposals have enjoyed celebrity endorsement, but are not supported by medical evidence and have contributed to dangerous under-vaccination in the national child population. While he denies being anti-vaccine, Sears has been described by many as anti-vaccine and as a vaccine delayer.
Views on vaccines
Sears is known for his views on vaccine scheduling. He recommends that parents avoid or delay vaccinating their children, counter to the consensus recommendations of medical bodies, and his book recommends that parents follow his two alternative vaccine schedules, rather than that of the American Academy of Pediatrics. His proposals are popular with parents who are influenced by incorrect information propagated by anti-vaccination activists who seek a "compromise" between embracing and avoiding vaccination. This has contributed to under-vaccination in the US child population, putting public health at risk.
In 2014, Sears said that he thinks "the disease danger is low enough where I think you can safely raise an unvaccinated child in today's society."
Although he is characterized as an anti-vaccine doctor and a vaccine delayer, Sears does say that vaccines work: "Chicken pox, measles, whooping cough, polio, diphtheria, all these diseases that we no longer see very much of anymore, I do say that the vaccines are responsible for getting rid of these." Sears is against mandatory vaccination.
Sears has encouraged parents who choose not to vaccinate their children not to tell others of their decision, writing: "I also warn them not to share their fears with their neighbors, because if too many people avoid the MMR, we'll likely see the diseases increase significantly." This position has been criticized as encouraging "free riding" on the herd immunity created by those who do vaccinate: "This is clearly immoral free-riding, it demonstrates a willingness to make unfair use of the contributions others have made to social cooperation." In 2008, Sears told the New York Times that 20% of his patients do not vaccinate at all, and that another 20% vaccinated partially. He also said that “I don’t think [vaccination] is such a critical public health issue that we should force parents into it." He continues to convey these views on his popular podcast, The Vaccine Conversation. Dorit Reiss rejects the podcast episodes as a source of medical information, as they "repeat anti-vaccine talking points, overstate vaccine risks and understate the benefits".
Sears opposed California Senate Bill 277, a California state law finalized in June 2015 that eliminated non-medical vaccine exemptions. While advocating against passage of the law during an April 2015 Senate hearing, Sears acknowledged it would not prevent patients from seeking medical exemptions or penalize doctors for granting them. He claimed that he opposed it because, in his experience, many doctors would not take reports of prior adverse vaccine reactions seriously and could not be relied upon to issue medically indicated exemptions.
In a June 2015 Facebook post, Sears compared non-vaccinating parents to Nazi-persecuted Jews. Sears later edited out the Holocaust comparison and added an apology to the end of the post. In a piece published by The Daily Beast, pediatrician Daniel Summers labeled the comparison "disgraceful":
"To compare the plight of the Jews under Hitler to that of those who willingly forego a preventive treatment that safeguards not only the health of their children, but the community as a whole is to lose all moral grounding. It is to purloin the most appalling suffering of the 20th century’s greatest victims, and assign it to those whose choices make not only themselves but their neighbors less safe. It is repulsive.... Dr. Bob Sears should be ashamed of himself."
Vaccines and autism In his 2010 book, The Autism Book, Sears recommended any child diagnosed with autism not be vaccinated further and said he respected parents' decisions not to vaccinate younger siblings out of an abundance of caution. He also falsely suggested autistic children (especially those who were given any vaccine containing the preservative thimerosal) might benefit from chelation therapy to clear their bodies of mercury and other heavy metals. Sears claimed "the mainstream medical community" was using the death of an autistic child inadvertently given the wrong chelation agent to unfairly demonize the treatment. He also falsely claimed traditional heavy-metal blood tests were not reliable and that parents should instead consider how much thimerosal their children were exposed to through vaccinations and how well they responded to other biomedical treatments to determine if chelation was warranted.
In The Autism Book, Sears further claimed some children could fully recover from autism (which is actually lifelong and incurable), directed readers to the websites of several anti-vaccine organizations (including AutismOne, Generation Rescue, SafeMinds and Talk About Curing Autism), and promoted various other discredited or unproven means of treating or preventing autism (including intravenous immunoglobin therapy, hyperbaric oxygen therapy, and gluten-free, casein-free diets).
In a September 2019 interview with the Los Angeles Times, Sears alleged it was "biologically plausible" that the MMR vaccine was linked to autism, a long-debunked claim popularized by the fraudulent research of anti-vaccine activist Andrew Wakefield and colleagues. Sears also suggested vaccines may be the reason behind increasing autism prevalence (which experts have largely attributed to greater awareness and changes to diagnostic criteria). Pediatrician Paul Offit told the publication Sears was taking advantage of the fact that scientists cannot prove a negative to give the false impression that it was still an open question as to whether vaccines and autism were linked. In response to Offit, Sears acknowledged existing studies did not support such a link, but disputed that one could definitively conclude that no link existed.
In a March 2025 post to his official website, Sears falsely claimed thimerosal was a "known neurotoxin" that posed an elevated risk to children and pregnant women; he also falsely claimed that no thorough, independent research had proven flu shots contained a safe amount of it. Sears further falsely alleged aluminum adjuvants used in vaccines were a neurotoxin that could accumulate in the brain and potentially "contribut[e] to neurological conditions," including Alzheimer's disease and autism.
It is scientific consensus that there is no link between any vaccine or vaccine ingredient and autism and that the aluminum and thimerosal sometimes used in vaccines are not harmful. Chelation therapy has never been proven effective to treat autism and has sometimes resulted in death or other serious complications when improperly administered to autistic children.
Alternative vaccine schedules
In 2007, Sears published The Vaccine Book: Making the Right Decision For Your Child through the Sears Parenting Library, and, as of 2012, it had sold more than 180,000 copies, and garnered support from celebrities. The book includes his two alternative vaccine schedules: "Dr Bob’s Selective Vaccine Schedule" is for those "who want to decline or to delay vaccines". "Dr Bob's Alternative Vaccine Schedule" is for those "who worry that children are receiving too many vaccines too early". This schedule involves spreading out the vaccines received by the child, and separating some vaccines that would otherwise be combined. The book has been described by Vox as "basically a guide to skipping vaccines," and that "it may as well be called The Anti-Vaccine Book."
Sears has said that he created his alternative vaccine schedules to allow parents to vaccinate their children "in a more gradual manner" rather than by following the schedule recommended by the Centers for Disease Control and Prevention (CDC). His notions, for example that vaccination risks causing "antigenic overload", are, however, based on misconceptions and not sound scientific evidence. On an episode of All In with Chris Hayes, Sears admitted that there was no published, peer-reviewed evidence to support the notion of vaccine overload, and that "my precautions about spreading out vaccines are theoretical, a theoretical benefit to kids..." Health journalist Julia Belluz has stated: "From a scientific standpoint, Sears is a quack: while he claims to be a vaccines expert, he is not a researcher and has never conducted his own vaccine science." Regarding his theory of vaccine overload, "according to the data mustered by the scientific community, he's simply wrong."
In 2008, Sears' "intentionally undervaccinated" seven-year-old patient"The importation resulted in 839 exposed persons, 11 additional cases (all in unvaccinated children), and the hospitalization of an infant too young to be vaccinated. Two-dose vaccination coverage of 95%, absence of vaccine failure, and a vigorous outbreak response halted spread beyond the third generation, at a net public-sector cost of $10 376 per case. Although 75% of the cases were of persons who were intentionally unvaccinated, 48 children too young to be vaccinated were quarantined, at an average family cost of $775 per child." "As it turns out, the boy who spread measles is a patient of Dr. Bob Sears,..." was identified as the index patient who started a measles epidemic in 2008, an epidemic which was the largest outbreak in San Diego since 1991. The epidemic "resulted in 839 exposed persons, 11 additional cases (all in unvaccinated children), and the hospitalization of an infant too young to be vaccinated....[with] a net public-sector cost of $10,376 per case.... 48 children too young to be vaccinated were quarantined, at an average family cost of $775 per child".
Reception Sears' viewpoints and The Vaccine Book have been criticized by the press and numerous medical professionals.
Offit wrote that "Sears sounds many antivaccine messages" in the book. Sears has been criticized by David Gorski, who wrote that Sears is anti-vaccine, and by Emily Willingham, who has dismissed The Vaccine Book as "non-evidence-based." Steven Novella criticized the book's attempt to tell both sides of, and assume a moderate position in, the vaccine debate as like "trying to compromise between mutually exclusive positions, like Young Earth creationism and evolution".
Pediatrician Rahul Parikh has said Sears is someone whose "understanding of vaccines is deeply flawed," that his Vaccine Book "is a nightmare for pediatricians like me," and "is peppered with misleading innuendo and factual errors". He also writes that "Sears misleads parents," using "tactics [like] soft science, circular logic, reporting rumors and outright falsehoods".