We don't know for sure whether or not peanut oil is now or ever has been in any vaccine.
Peanut oil is not referenced in any of the FDA-approved vaccine package inserts for the vaccines currently in the VaxCalc database.
In 1964, The New York Times ran a story called PEANUT OIL USED IN A NEW VACCINE. The story ends with "Their patent is No. 3,149,036"
Some claim that because the 1964 NY Times article points out that "The new vaccine is still under study and is not yet licensed for general use" - it therefore must be that peanut oil was never used in vaccines.
But is that true? The article is from 1964 - 54 years ago. Since the article was published, 54 years have passed and (as of early 2018) US patent 3,149,036 has been referenced by 42 newer patents.
We don't know if any of the referencing patents make use of peanut oil and have ever been used in a US licensed vaccine. If you have time and the expertise to trace through patent filings, please read a patent and let us know what you discover. We will publish your findings here.
Another reason its not possible to say with confidence that peanut oil is not and never has been in a US licensed vaccine is that some ingredients are trade secrets and kept confidential. The FDA does not require vaccine manufacturers to make public every ingredient in a vaccine - some may be kept secret. This is documented on page 71 and page 77 of the 6th edition of the textbook Vaccines by Plotkin, Orenstein and Offit:
You can search for "trade secret" in the Vaccines textbook via the Google Books plugin: