Fact Check

Are Pharmaceutical Companies Hiding the Presence of Peanut Oil in Vaccines?

Despite arguments that vaccines are to blame for rising peanut allergies, the claim that peanut oil is present in inoculations rests almost entirely on a misreading of newspaper articles from the 1960s.

Published Feb. 16, 2017

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Peanut oil is secretly present in childhood vaccines and flu shots.

Among the many epidemiological trends blamed on vaccines, one of the lesser known fallacies is that they are the cause of an increased incidence of childhood peanut allergies in the United States and other nations.  Alternative health website and “alien false flag” watchdog Natural News, for example, used this argument in a 13 February 2017 story arguing that President Trump’s allegedly exemplary health is, in part, thanks to his never having received a flu shot:

Have you ever wondered why hundreds of thousands of U.S. children are allergic to peanuts? A hundred years ago, peanut allergies were unheard of, yet today, as many as 2 million U.S. children are allergic to them. What changed? The flu shot.

Though articles and individuals attempting to make this link propose a variety of mechanisms for the ways in which an inoculation could contribute to the development of peanut allergies, each relies on the false premise that vaccines (childhood and/or influenza) contain undisclosed traces of peanut oil.

The most common narrative found online is that peanut oil is used as what is known as an adjuvant (a chemical that increases the body's immune response to an inoculation) but loopholes in the legal system allow this information to remain undisclosed.

This assertion appears to have its roots in the 2011 book The Peanut Allergy Epidemic by Heather Fraser, which has a section about the potential presence of peanut oil adjuvants in vaccines. Fraser attempts to argue that some kinds of adjuvants in injections (not specifically childhood vaccines) may have, through poorly understood mechanisms, sensitized children to peanut and other allergies. This specific chapter (and the evidence it cites) appears to be the basis for a number peanut oil claims on numerous anti-vaccine websites.

The web site VaccineInformationNetwork.com summarizes that narrative in a way that is representative of many posts:

Many different substances have been used as adjuvants over the last 100 years, and the scientists have been constantly on the lookout for more dangerous substances which produce extreme immune reactions in the human body, until one day they stumbled upon a substance that delivered the kind of deadly reaction they were looking for: Peanuts.

Peanuts were first used as an adjuvant in vaccines in the mid-60s. We know this because the startling admission was made in the New York Times on 18 Sep 1964, where the author described how a newly patented ingredient including peanut oil was being added to the flu vaccine as an adjuvant in order to ‘enhance the vaccines strength’. Peanut oil became the model for subsequent vaccines, and by the 1980s it had become the preferred adjuvant for the manufacturers.

Today, peanut oil is a common trade secret ingredient used in vaccine adjuvants. They claim it as a trade secret so their competitors wont [sic] ‘steal their vaccine formulas’, but in reality they do it so they don’t have to list it as an ingredient, in the hope that the unaware public wont realise it is the cause.

While the Vaccine Information Network post is a bit more dramatic in its language, both that post and the book from which that information is derived make a number of claims that require investigation:

  • Peanuts (or peanut oil) were used in vaccines that were given to the general public starting in the mid-1960s.
  • Peanut oil “became a model” for subsequent adjuvants in vaccines.
  • By the 1980s peanut oil was the preferred adjuvant for vaccines.
  • Peanut oil is currently used in adjuvants, but there are legal loopholes that that allow vaccine manufacturers to hide this information from the public.

Vaccines Have Used Peanut Adjuvants Since The 1960s — False

The notion that vaccines containing peanut oil adjuvants were introduced to the public, as presented in Fraser’s book, relies on a 1964 New York Times report about a clinical trial conducted by the pharmaceutical company Merck of a flu vaccine that contained a new peanut-oil based adjuvant given the name "Adjuvant 65", which at the time seemed to show considerable promise:

A pharmaceutical manufacturer has developed a vaccine that it predicts will considerably lengthen immunity from influ­enza and other virus infections, thereby requiring fewer “shots.”

The key ingredient, called Adjuvant 65, which contains peanut oil, was patented this week for Merck & Co., Inc., by Dr. Allen F. Woodhour and Dr. Thomas B. Stim. [...]

The current issue of the New England Journal of Medicine re­ports favorably on studies in which 880 persons received killed influenza virus in Adju­vant 65.

This article, however, in no way demonstrates that vaccines commonly contained peanut-oil adjuvants in the 1960s; In fact, it makes it clear that they were not even approved for public use in the United States, explicitly stating “the new vaccine is still under study and is not yet licensed for general use.”

This kind of bait-and-switch is also applied to another New York Times article from 1966. Here, crucially, Fraser says that in 1966, "Merck introduced this novel peanut oil additive to the public in a flu vaccine”, implying the product was approved for public use. The only problem is the story she cited concerns a conference presentation by the same researchers in the 1964 study, and it once again makes it clear that it is not a publicly available concoction, but instead still undergoing testing:

Studies of an additive to an influenza vaccine show that it increases the potency and duration of the vaccine's protective effect. This was reported today at an international conference on vaccines here that is sponsored by the World Health Organization and the Pan-American Health Organization.

The additive — called an adjuvant — has been tested on 15,000 adults and children. To date, the studies suggest that use of the adjuvant produces a high level of immunity that lasts for several years. Ordinarily, it is believed that flu vaccine produced from a killed virus produces an immunity that is likely to last only one season.

When asked for clarification, Fraser told us via email that she did not intend to suggest that Adjuvant 65 was ever used in American vaccines:

Adjuvant 65-4 [the specific formulation tested then] was never licensed for use in the US. It was used in vaccines in clinical trials, some large scale over a period of at least 10 years. I did not mean to suggest that this adjuvant was used outside of clinical trials in the US.

Intent or not, it appears likely that many anti-vaccine websites have taken these two citations as proof that Adjuvant 65, or some peanut oil containing progeny, is and remains a commonly used ingredient in vaccines. In reality, however, Adjuvant 65 was never approved for use in the United States and many other countries due to concerns about its toxicity. No human vaccines presently contain the compound.

Peanut Oil “Became a Model” for Subsequent Adjuvants in Vaccines — False

This wording is vague as it does not define what “became a model” actually means. One thing it does not mean, however, is that the failure of Adjuvant 65 resulted in a number of other more successful and widely used peanut based vaccine adjuvants, as there has not been a single such product licensed for use in human vaccines.

A more accurate narrative concerning vegetable oil based adjuvants and the relative importance of Adjuvant 65 in medical history can be found in a 1993 review of the topic, which describes the efforts to create vegetable oil adjuvants (which can be metabolized by the body) as a replacement for mineral oil adjuvants (which, because they cannot, lead to health concerns):

Various kinds of emulsions with different oil samples have been evaluated in a search for a stable, non-toxic and better adjuvant. As an alternative to mineral oil emulsion adjuvants, [the research group associated with Merck] designed a vegetable oil adjuvant, 'Adjuvant 65', consisting of 86% peanut oil, 10% Arlacel A [...] as emulsifier and 4% aluminium monostearate as stabilizer [...].

When tried in humans, this adjuvant appeared to be safe and potent but with less adjuvanticity than [the most common mineral oil adjuvant]. Although Adjuvant 65 was licensed for general use in one country, its use was discontinued due to reactogenicity for man [...]

Despite the absence of tumour formation in [...] several thousand persons inoculated with Adjuvant 65 influenza vaccine followed for 10 years, further work on these adjuvants of vegetable oil with Arlacel A slowed down or even stopped when it was shown in one report that Arlacel A [might be carcinogenic in one strain of lab mice]. [...]

[One research group] developed an adjuvant with sesame oil double emulsion without Arlacel A which could be metabolized. This preparation had a good adjuvant effect on the antibody response of mice. Another preparation containing highly refined peanut oil emulsified in aqueous arbovirus vaccine with glycerol and lecithin increased antibody production and induced protective immunity in several experimental animals. Unlike Arlacel A, glycerol and lecithin are readily metabolized normal host constituents. This formula of peanut oil, glycerol and lecithin has been described as relatively non-reactogenic in tissues. However [as of 1993], there is still no oil emulsion adjuvant which may be used in humans.

In her book, Fraser cites a single research paper testing a peanut-oil based adjuvant in a variety of animal models, as well as a handful of patent applications, to defend the claim that it was “a model” for other adjuvants at the time.

While it is unclear what became of that particular adjuvant in that study, no peanut-oil adjuvant has ever been licensed for use in American vaccines, meaning it likely didn't go anywhere. At least one of the patents Fraser cites, incidentally, certainly didn’t go anywhere — it is currently listed as expired because of lack of payment for administrative fees. Far from being a model for new adjuvants, peanut oil could more accurately be described as a dead end.

By the 1980s Peanut Oil Was the Preferred Adjuvant for Vaccines — False

This claim, incidentally, is not made in Fraser’s book, but is included on the VaccineInformationNetwork.com post, and may stem from a misreading of her statement that the inclusion of peanut oil in vaccine adjuvant patents became "common practice".

Regardless of the relative meaninglessness of the term "common practice" in this context (or the irrelevance of a patent application to a larger discussion of epidemiological trends) claiming that peanut oil was a preferred adjuvant for vaccines by the 1980s is about as "alternative fact" as they come. As discussed above, efforts to develop vegetable oil based adjuvants essentially stopped in the late 1970s. There are, currently, only two types of adjuvants approved for U.S. use: aluminum salts and a single, animal-derived oil emulsion used only in the Cervarix vaccine and only since 2009.

Far from being the preferred adjuvant beginning in the 1980s, peanut oil adjuvants have never been licensed for human use in US vaccines, and are currently not licensed for human vaccine use anywhere else.

There Are Loopholes That Make it Legal for Vaccine Manufacturers to Hide the Presence of Peanut Oil from the Public — False

In case the complete and total lack of evidence supporting the claim that peanut oil can be found in vaccines convinced you that they were peanut free, anti-vaccine advocates also throw in a burden-of-proof logical fallacy to contend with: that pharmaceutical companies are doing it secretly and there is literally no way to know for sure.

A number of websites make the argument that there are legal loopholes that allow pharmaceutical companies to “get away” with putting peanut oil in vaccines. Fraser makes that argument in her book, too, but without any supporting evidence:

However, with the sharp rise in lawsuits against vaccine makers starting in the mid-1970s, public knowledge of exact ingredients in vaccines or other pediatric injections became circumscribed. Vaccine makers no longer excitedly announced new ingredients as Merck did in 1964 with the peanut-oil-based Adjuvant 65-4. The public had no way of knowing fully what was being injected into their children.

The response to the increased number of lawsuits was not to reduce regulations regarding disclosure of ingredients, but to set up a “no-fault” vaccine court to settle lawsuits against pharmaceutical companies that produce vaccines. This court significantly reduced pharmaceutical companies’ liability, which would make them less concerned with lawsuits, not more.  United States law remains quite clear on the labeling requirements for vaccines, according to Section 610.61 of Title 21 of the US Code of Federal Regulations.

This code explicitly requires the presence of any sensitizing substance (proteins left over from a vegetable oil, for instance) as well as the specific adjuvant present (along with pretty much every chemical that would have been used at any point, even if no longer present) to be clearly defined:

The following items shall appear on the label affixed to each package containing a product: [...]

(l) Known sensitizing substances, or reference to an enclosed circular containing appropriate information;

(m) The type and calculated amount of antibiotics added during manufacture;

(n) The inactive ingredients when a safety factor, or reference to an enclosed circular containing appropriate information;

(o) The adjuvant, if present;

(p) The source of the product when a factor in safe administration;

(q) The identity of each microorganism used in manufacture, and, where applicable, the production medium and the method of inactivation, or reference to an enclosed circular containing appropriate information;

The complete contents of all US approved vaccines can be found on the CDC web site.

Ok, So It’s Not in Adjuvants, But They Do “Brew” Vaccines in Peanut Oil — False

Some venues avoid the concept of peanut oil based adjuvants entirely. These publications, most notably Natural News (which referenced a series of posts authored by a “doctor” who, by their own disclaimer, may not exist), instead claim that peanut oil is (or could be) used as a “growth medium” in the production of vaccines, which could then leave undetectable traces of peanut proteins or other allergens that companies would be under no obligation to disclose:

The influenza vaccine is brewed in peanut oil that’s not listed as an ingredient because only “trace amounts” remain – not enough according to the FDA and CDC to harm people. Peanut oil has been used in vaccines since the 1960s, but because it doesn’t “show up” in the final vaccine product, the manufacturers are allowed to leave it off the package inserts.

Peanut oil is just one “growth medium” that vaccine manufacturers use to make vaccines, like egg embryo (protein) and casein (milk). This is what they use to make MMR and influenza vaccines.

By asserting that "peanut oil has been used in vaccines since the 1960s" — a reference to the previously mentioned trial study — Natural News may be conflating adjuvants with growth media. A "growth medium" is simply a concoction of nutrients, sugars and other hydrocarbons that help either bacterial cells or cells hosting a virus to survive. In a post explaining why animal products are sometimes used to achieve this goal, the Food and Drug Administration describes the basics:

Vaccines contain either killed or weakened forms of disease-causing bacteria or viruses, or components of these that stimulate a response by the body's immune system, which then protects against the development of disease. In the late 19th century, microbiologists began to grow bacteria in the laboratory. The early bacteriologists tried to mimic as closely as possible the environment in an infected person's tissues by using solutions containing sugars, salts, and various meat extracts to make "growth media." These kinds of conditions were quite successful in growing bacteria and then viruses in the lab, because these media supplied the many necessary nutrients. Although synthetic media have been developed for growth of many medically important microorganisms, some still require additional nutrients which are easily provided by animal-derived products such as serum and blood. Viral vaccines are produced in living cells, which, similarly, require the addition of complex growth media components, such as fetal calf serum.

The generally untestable argument made here is that nothing is stopping pharmaceutical companies from using peanut oil in their growth media. From a legal standpoint, however, this too is false. As mentioned above, U.S. law requires “the identity of each microorganism used in manufacture, and, where applicable, the production medium” to be disclosed.

The argument that pharmaceutical companies don’t need to report things that appear only in trace amounts or not at all is equally false. According to the disclaimer on the CDC’s list of vaccine ingredients:

This table includes not only vaccine ingredients (e.g., adjuvants and preservatives), but also substances used during the manufacturing process, including vaccine-production media, that are removed from the final product and present only in trace quantities.

While some of these media are patented products, their method of production and ingredients are publicly known — and peanut oil free.

The Bottom Line

Despite all of the above hoops one must jump through to debunk this myth, the basic facts are quite simple. Arguments suggesting that peanut oil is present in vaccines of any kind rely on using a clinical trial for a peanut-oil based adjuvant in the 1960s as evidence that peanut oil adjuvants are and have been in widespread use.

Those trials were a failure. No peanut oil based adjuvants (or growth media) are used in human vaccines, and there are no legal loopholes (at least in the United States) that would allow pharmaceutical companies to avoid disclosure of different compounds used in their production. In response to our inquiry about the claims made in her book, Fraser told us:

While the oil has a history of use in pharmaceuticals, I have no evidence that it is used in childhood vaccines.

Despite this, Fraser’s book is still often offered as the definitive source for the “fact” that childhood vaccines (or flu shots) contain peanut oil.


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Alex Kasprak is an investigative journalist and science writer reporting on scientific misinformation, online fraud, and financial crime.