Vaccine Ingredients – Yeast

Can people with yeast allergies get vaccines?

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.

Severe allergic reactions (including hives, difficulty breathing or low blood pressure) have been reported after receipt of hepatitis B vaccine (about 1 case per 600,000 doses). However, allergy to yeast proteins does not appear to be the cause of these allergic reactions.


Wiedermann G, Scheiner O, Ambrosch F, Kraft D, Kollaritsch H, et al. Lack of induction of IgE and IgG antibodies to yeast in humans immunized with recombinant hepatitis B vaccines. Int Archs Allergy Appl Immun 1988;85:130-132.

Volunteers were inoculated with three doses of yeast-derived hepatitis B vaccines at monthly intervals and compared with plasma derived vaccines. Before and four weeks after  immunizations, blood samples were tested for presence of IgE or IgG antibodies against yeast antigens related to Saccharomyces cerevisiae and Candida albicans, respectively, as cross-reactivity exists between the two genera. No rise in IgE antibodies against Saccharomyces cerevisiae antigens nor in IgG antibodies against Candida albicans antigens was found. The authors concluded that yeast proteins in recombinant hepatitis B vaccines do not cause type I or type III allergic reactions.

Petre J, Van Wijnendaele F, De Neys B, Conrath K, Van Opstal O, et al. Development of a hepatitis B vaccine from transformed yeast cells. Postgrad Med H 1987;63(Suppl 2):73-81.

Researchers tested subjects before and after exposure to the yeast-derived recombinant hepatitis B vaccine for anti-yeast antibodies. All subjects tested positive for anti-yeast IgG antibodies before vaccination, and 1-2% of subjects had low levels of anti-yeast IgE antibodies prior to immunization.  IgG antibody titers fluctuated after immunization, and were not related to any adverse reactions. Yeast-derived vaccine is safe, even in subjects with pre-existing anti-yeast IgE antibodies.

Zajac BA, West DJ, McAleer WJ, Scolnick EM. Overview of clinical studies with hepatitis B vaccine made by recombinant DNA. J Infect 1986;13(Suppl A):39-45.

The antigen used in the yeast-recombinant hepatitis B vaccine is derived from a culture of Saccharomyces cerevisiae (common baker’s yeast) and trace quantities of yeast protein exist within the product. As such, there is a theoretical concern that administration of a vaccine prepared in yeast might induce allergic reactions to yeast proteins. Researchers tested the sera of 133 persons before and after receipt of the recombinant vaccine for anti-yeast antibodies. One-hundred percent of individuals had anti-yeast IgG in both pre- and post-vaccination samples, presumably from exposure through eating bread. Levels fluctuated after receipt. Adverse reactions were not more frequent in persons with rises in yeast antibody titers.

Reviewed by Paul A. Offit, MD on December 10, 2018

Materials in this section are updated as new information and vaccines become available. The Vaccine Education Center staff regularly reviews materials for accuracy.

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