Dr. Tetyana's Perspective
on Vaccination and Natural Immunity
Gastrointestinal food allergy to BAKER'S yeast after receiving yeast-recombinant Hepatitis B vaccine
By Tetyana Obukhanych, Ph.D.
What do we know about yeast-recombinant vaccine technology and its risks to GI health?
The yeast species used in yeast-recombinant vaccine production technology is called Saccharomyces cerevisiae. The same yeast species, commonly known as baker’s or brewer’s yeast, is used in making bread, beer, wine, and as a nutritional yeast supplement. Saccharomyces lives naturally on grapes, plums, and some other fruit. This yeast may also be part of human gut biome in some individuals. Because of this, priming the immune system to react to this yeast species may be fraught with negative consequences in a subset of susceptible individuals.
There are currently two vaccines that utilize yeast-recombinant technology: the Hepatitis B vaccine and the HPV vaccine . The Hepatitis B vaccine is heavily contaminated with the Saccharomyces cerevisiae yeast antigen. In fact, there is potentially 1000 times more yeast antigen (5 mg) than actual Hepatitis B viral antigen (5 mcg) in some Hepatitis B vaccine brands.
The Children’s Hospital of Philadelphia (CHOP) website  currently lists three publications dating back to the late 1980s, stating that the yeast-recombinant Hepatitis B vaccine didn’t influence antibody titers to yeast antigens and didn’t trigger allergic reactions even in those subjects who already had yeast IgE antibodies.
However, a novel type of food allergy, called non-IgE-mediated gastrointestinal allergy, or GIFA, utilizes an entirely different Th2 cell-mediated mechanism that doesn’t involve antibodies (Morita et al., 2013) , making those old antibody-focused studies outdated and unsuitable for establishing vaccine safety for GI health. GIFAs do not manifest as typical allergy but instead affect gut function.
Although the most severe form of GIFA, a condition called FPIES is relatively rare, GIFAs can take on a variety of clinical manifestations, some of which are all too common in the pediatric population. For example, a scientific review by Nowak-Węgrzyn et al. (2015)  states: “It has been demonstrated that isolated gastrointestinal dysmotility (too rapid, too slow, disturbed, or retrograde) is caused by non-IgE-GIFAs in a subset of patients manifesting as pathologic gastroesophageal reflux, vomiting, delayed gastric emptying, diarrhea, constipation, or irritable bowel syndrome.”
I myself started experiencing frequent bouts of GI pain after receiving the Hepatitis B vaccine in my graduate research immunology program. No helpful explanation was ever given to me by healthcare professionals about its cause. We are not taught what’s in vaccines in graduate or medical schools. Only years later, as I started looking into vaccine ingredients and their contaminants on my own, did I realize that I might have been immunologically primed to react to baker’s yeast with GI pain. I was able to become virtually pain-free by excluding every possible source of yeast from my diet. Re-introduction of it brings the bouts of pain back.
With the yeast-recombinant Hepatitis B vaccine on the childhood schedule, it is theoretically possible that when infants are primed to baker’s yeast antigen at birth, they develop long-lived Th2 T-cell memory to that antigen. Their dietary exposure to baker’s yeast starts once solids are introduced later on in life, which may only then trigger GIFA reactions resulting in inexplicable GI symptoms, abdominal pain, and behavioral changes.
Published guidelines inform us that a suspected non-IgE-mediated GIFA can only be identified based on the resolution of symptoms when a suspect food is avoided for several weeks and the return of symptoms upon subsequent food challenge (Muraro et al., 2014) . It is not currently based on any standard lab test.
But are children with persistent GI symptoms or GI pain being properly tested for GIFA to baker’s yeast or to other foods that can be traced to contaminants in vaccines they have received? (Another example of such contamination is casein, detected by Kattan et al., 2011  in all tested batches of DTaP and Tdap.)
It is time we recognize the cause of the current GI health crisis in the pediatric population and put an end to it.
Tetyana Obukhanych, PhD is Immune System Educator at Building Bridges in Children's Health (BBCH), an online community of parents and doctors dedicated to learning the science that impacts children's health. JOIN BBCH membership to access Dr. Tetyana's Natural Immunity Fundamentals (NIF) lecture-series and slideshows from all prior BBCH events.
 “Hepatitis B vaccines are made using baker’s yeast and residual quantities of yeast proteins are contained in the final product. Engerix-B® (GlaxoSmithKline) and Heplisav-B® (Dynavax Technologies) contain no more than 5 mg per ml and Recombivax HB® (Merck and Co.) contains no more than 1 mg per ml of yeast proteins. Two combination vaccines, Pediarix® and Twinrix®, that contain the hepatitis B vaccine (Engerix-B) also contain no more than 5 mg per ml. Pediarix combines hepatitis B with diphtheria, tetanus, pertussis and polio vaccines; Twinrix, an adult vaccine, combines hepatitis A and hepatitis B vaccines. The version of the human papillomavirus (HPV) vaccine contains less than 0.007 mg of yeast proteins.” Source: Children’s Hospital of Philadelphia (CHOP) website, https://www.chop.edu/centers-programs/vaccine-education-center/vaccine-ingredients/yeast (accessed on January 23, 2020).
 Morita et al. Antigen-specific T-cell responses in patients with non-IgE-mediated gastrointestinal food allergy are predominantly skewed to T(H)2. J Allergy Clin Immunol. 2013 Feb;131(2):590-2.e1-6. PubMed PMID: 23083674.
 Nowak-Węgrzyn A, Katz Y, Mehr SS, Koletzko S. Non-IgE-mediated gastrointestinal food allergy. J Allergy Clin Immunol. 2015 May;135(5):1114-24. Review. PubMed PMID: 25956013.
 Muraro et al. AEAACI Food Allergy and Anaphylaxis Guidelines Group. EAACI food allergy and anaphylaxis guidelines: diagnosis and management of food allergy. Allergy. 2014 Aug;69(8):1008-25. PubMed PMID: 24909706.
 Kattan et al. Anaphylaxis to diphtheria, tetanus, and pertussis vaccines among children with cow's milk allergy. J Allergy Clin Immunol. 2011 Jul;128(1):215-8. PubMed PMID: 21624648.