VEC Vaccine Notes

Vaccine Education Center at Children’s Hospital of Philadelphia

Listen to “VEC Vaccine Notes,” a video and podcast series presented by the Vaccine Education Center at Children's Hospital of Philadelphia. Each episode offers vaccine information in a convenient format, so families have the answers they need to make informed decisions, including details and context that addresses what they may have heard in the news or in conversation with others. This podcast is for general informational and educational purposes only and is not to be considered as professional medical advice for your personal health or for your family's personal health. You should not use it to replace any relationship with a physician or other qualified healthcare professional. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult your physician or, in serious cases, seek immediate assistance from emergency personnel. Clinicians must rely on their own informed clinical judgment in making recommendations to their patients. ©2026 The Children’s Hospital of Philadelphia.

  1. 2d ago

    Byproducts: Egg Proteins & Yeasts - VEC Vaccine Notes | Vaccine Education Center at Children’s Hospital of Philadelphia

    Find out how egg proteins and yeast cells are used during the making of some vaccines. Charlotte Moser, Co-Director of the Vaccine Education Center, talks about these two manufacturing byproducts, discussing the vaccines that contain each, the relative quantities, and health-related considerations. The two vaccines made in eggs are the yellow fever vaccine and some versions of the influenza vaccine. While the measles, mumps, rubella vaccine (MMR) is made using chicken cells, it is not made in eggs, so it doesn’t contain egg proteins, and, therefore, egg allergies are not a concern for receipt of that vaccine. She also discusses why the risk for an allergic reaction from vaccines-containing egg proteins is very low and provides egg protein-free options for influenza vaccine. The vaccines that use yeast cells in production are the hepatitis B and human papillomavirus, or HPV, vaccines. As with egg proteins, yeast cells are removed during the purification process as well, so exposure is limited and risk to people with yeast allergies is minimal to theoretical. Check out the video version on YouTube. Watch the episode to find: To learn more about egg proteins and its use in vaccines, visit https://bit.ly/egg-products. To learn more about yeasts and its use in vaccines, visit https://bit.ly/vec-yeast. To learn more about vaccine ingredients, please visit https://bit.ly/vec-vax-ingredients. Questions? Submit the VEC Vaccine Notes form, https://bit.ly/contact-vec-vaccine-notes. For other vaccines, diseases or general questions about vaccines, check out https://vaccine.chop.edu/. Subscribe to our Parents PACK newsletter, https://bit.ly/3KfLUoO.

  2. Nov 4

    Byproducts: SV40 (Simian Virus 40) - VEC Vaccine Notes | Vaccine Education Center at Children's Hospital of Philadelphia

    Find out how some vaccine recipients in the 1950s and early 1960s were exposed to simian virus 40 (SV40), a virus that infects monkeys. Charlotte Moser, Co-Director of the Vaccine Education Center, talks about the four vaccines that were contaminated with SV40 and addresses the health concerns, including cancer risks, for those who were exposed. Although SV40 was found to cause cancer in lab animals, studies found no link between the contaminated vaccines and development of cancer in people. Importantly, since the early 1960s, cell lines used to make vaccines in the U.S. are free of SV40, so this is no longer a vaccine safety concern. Check out the video version on YouTube. Watch the episode to find: Who discovered SV40 and how it was handled Which vaccines were affected and how many people were estimated to be exposed by each Which types of cancers have been found to have DNA from SV40 and the larger context of scientific findings Why the studies of SV40 have been reassuring To learn more about SV40, please visit https://bit.ly/sv40. To learn more about vaccine ingredients, please visit https://bit.ly/vec-vax-ingredients. Questions? Submit the VEC Vaccine Notes form, https://bit.ly/contact-vec-vaccine-notes. For other vaccines, diseases or general questions about vaccines, check out https://vaccine.chop.edu/. Subscribe to our Parents PACK newsletter, https://bit.ly/3KfLUoO.

  3. Oct 28

    Byproducts: Fetal Cells - VEC Vaccine Notes | Vaccine Education Center at Children’s Hospital of Philadelphia

    Find out why fetal cells are used to make vaccines as  Charlotte Moser, Co-Director of the Vaccine Education Center, explains that 1) viruses need cells to reproduce and 2) fetal cells are unlikely to be contaminated with other viruses due to the sterile environment of the womb. She also explains the Hayflick limit and cell passage. Because of cell passage and the ability to store fetal cells long term in liquid nitrogen, additional fetal cells are not needed to make the vaccines that use these types of cells. Moser delineates which vaccines use fetal cells in the production process, how each is made, and why the headlines aren’t always accurate, reassuring listeners that vaccines don't contain fetal cells, fetal tissues, fetal debris or parts of fetuses. As part of the production process, the vaccine virus is purified to remove cellular debris. Anything that's left is minimal and highly fragmented, so it can't cause harm. Lastly, she addresses fetal cells and religious concerns. Check out the video version on YouTube. Watch the episode to find: The three routinely used childhood vaccines that are made using fetal cells Three less commonly used or no-longer-available vaccines that are made using these cells Two issues scientists were trying to overcome when they opted to use these cells What the Hayflick limit is in biology The types and history of the different fetal cell lines used to make vaccines To learn more about fetal cells in vaccines, visit https://bit.ly/vec-fetal-cells. To learn more about vaccine ingredients, please visit https://bit.ly/vec-vax-ingredients. Questions? Submit the VEC Vaccine Notes form, https://bit.ly/contact-vec-vaccine-notes. For other vaccines, diseases or general questions about vaccines, check out https://vaccine.chop.edu/. Subscribe to our Parents PACK newsletter, https://bit.ly/3KfLUoO.

  4. Oct 21

    Byproducts: DNA & Human Proteins - VEC Vaccine Notes | Vaccine Education Center at Children's Hospital of Philadelphia

    Find out why DNA is contained in some vaccines and why it cannot cause harm. Charlotte Moser, Co-Director of the Vaccine Education Center, explores questions surrounding human proteins from fetal cells and explains how mRNA vaccines work.   She reassures listeners that any residual DNA or human protein after vaccine purification is so minimal and fragmented, measured in billionths or trillionths of a gram, that it’s incapable of causing harm. She also explains how built-in cellular signals, such as stop codons and poly(A) tails, limit the quantity of protein produced by any mRNA, including that introduced in COVID-19 mRNA vaccines, addressing persistent fears of perpetual COVID-19 spike protein production and tainted blood supplies. Check out the video version on YouTube. Watch the episode to find information about: Ways we are regularly exposed to DNA Considerations related to DNA damage How our bodies defend against exposures and damage to external DNA Two ways DNA can be introduced in vaccines Some viral infections that cause foreign DNA to remain in cells The protein-making process in every cell How our bodies make sure our cells aren’t overrun with excess protein and how that relates to concerns about continued spike protein production after receipt of COVID-19 mRNA vaccine Two considerations that generate questions related to proteins in vaccines Some examples of diseases caused by errors in protein production To learn more about DNA and its use in vaccines, visit https://bit.ly/vec-dna. To learn more about human proteins and vaccines, visit https://bit.ly/vec-proteins. To learn more about vaccine ingredients, please visit https://bit.ly/vec-vax-ingredients. Questions? Submit the VEC Vaccine Notes form, https://bit.ly/contact-vec-vaccine-notes. For other vaccines, diseases or general questions about vaccines, check out https://vaccine.chop.edu/. Subscribe to our Parents PACK newsletter, https://bit.ly/3KfLUoO.

  5. Oct 14

    Byproducts: Antibiotics - VEC Vaccine Notes | Vaccine Education Center at Children’s Hospital of Philadelphia

    Did you know that the first antibiotic, penicillin, was discovered by happenstance in the 1920s? Charlotte Moser, Co-Director of the Vaccine Education Center, touches briefly on this history as she discusses the use of antibiotics; health considerations, including allergic reactions and antibiotic resistance; and why antibiotics are used in vaccines. As she describes, any antibiotics that remain in vaccines are present in very small quantities, causing no harm. Find out more in this episode of VEC Vaccine Notes. Check out the video version on YouTube. Watch the episode to find out: How Alexander Fleming discovered the antibiotic properties of penicillin How World War II affected the development and availability of penicillin Some of the different considerations related to how antibiotics work Which types of antibiotics are used during the vaccine manufacturing process How many infections and deaths are caused by antibiotic resistance each year in the U.S. To learn more about antibiotics, please visit https://bit.ly/vec-antibiotics.  To learn more about vaccine ingredients, please visit https://bit.ly/vec-vax-ingredients. Questions? Submit the VEC Vaccine Notes form, https://bit.ly/contact-vec-vaccine-notes. For other vaccines, diseases or general questions about vaccines, check out https://vaccine.chop.edu/. Subscribe to our Parents PACK newsletter, https://bit.ly/3KfLUoO.

  6. Oct 7

    Byproducts: Formaldehyde - VEC Vaccine Notes | Vaccine Education Center at Children's Hospital of Philadelphia

    What is formaldehyde, and how much is present in vaccines? Find out in this episode of VEC Vaccine Notes. Charlotte Moser, Co-Director of the Vaccine Education Center, explains how our bodies naturally produce and break down formaldehyde every day — in quantities far exceeding those found in any vaccine. She talks about the differences between the gaseous and liquid forms of formaldehyde; the latter, called formalin, is the version used in vaccines. She also discusses where we encounter formaldehyde in daily life and why it remains in trace amounts as a purified byproduct in vaccines. This episode also explores the real-world health effects associated with long-term, high-dose occupational exposures, including cancers, and reveals why the minimal, infrequent exposure from childhood vaccines does not cause harm. Hint? A 2-month-old infant naturally has 10 to 220 times more formaldehyde circulating in their blood than what is delivered in any single vaccine. Check out the video version on YouTube. The different forms of formaldehyde What kinds of products and places it is found How much formaldehyde an infant can be exposed to from vaccines recommended during the first two years of life The situations when formaldehyde can cause health concerns To learn more about formaldehyde, please visit https://bit.ly/vec-formaldehyde. To learn more about vaccine ingredients, please visit https://bit.ly/vec-vax-ingredients. Questions? Submit the VEC Vaccine Notes form, https://bit.ly/contact-vec-vaccine-notes. For other vaccines, diseases or general questions about vaccines, check out https://vaccine.chop.edu/. Subscribe to our Parents PACK newsletter, https://bit.ly/3KfLUoO.

  7. Sep 30

    Preservatives: Thimerosal - VEC Vaccine Notes | Vaccine Education Center at Children’s Hospital of Philadelphia

    What is thimerosal, and why was it used as a vaccine preservative? Find out in this episode of VEC Vaccine Notes. Charlotte Moser, Co-Director of the Vaccine Education Center, explains the differences between elemental mercury (the silver-colored form of mercury found in products like thermometers and dental fillings), methylmercury (the type we’re exposed to when we eat fish), and ethylmercury (the preservative used in childhood vaccines). She details why small changes in the chemical structure between two compounds that might sound similar greatly impact the level of toxicity and how they are processed by our bodies. This episode also explores the history of thimerosal in multidose vials, why routinely recommended childhood vaccines in the United States transitioned to single-dose vials in the late 1990s, and what decades of rigorous scientific studies reveal about thimerosal and autism. Hint? Study after study found that thimerosal in vaccines does not cause autism. Check out the video version on YouTube. Listen to the episode to find out: About the worst, single-source mercury poisoning in history How ethanal and methanol can help us think about ethylmercury and methylmercury Symptoms of neurologic damage caused by mercury The different types of studies that looked at thimerosal exposure from vaccines Some of the known causes of autism and why we know mercury isn’t among them To learn more about thimerosal, please visit https://bit.ly/vec-thimerosal.  To learn more about vaccine ingredients, please visit https://bit.ly/vec-vax-ingredients. Questions? Submit the VEC Vaccine Notes form, https://bit.ly/contact-vec-vaccine-notes. For other vaccines, diseases or general questions about vaccines, check out https://vaccine.chop.edu. Subscribe to our Parents PACK newsletter, https://bit.ly/3KfLUoO.

  8. Sep 23

    Stabilizers: Gelatin and Polysorbate 80 & Vaccines - VEC Vaccine Notes | Vaccine Education Center at Children’s Hospital of Philadelphia

    Find out how gelatin and polysorbate 80 protect vaccines during manufacturing, storage and transport. Charlotte Moser, Co-Director of the Vaccine Education Center, also addresses common safety and cultural concerns related to these two vaccine ingredients, including severe allergic reactions, unfounded claims regarding polysorbate 80 and fertility, and religious guidelines surrounding porcine-derived gelatin. The discussion also includes a comparison of the amounts found in vaccines to exposures encountered in everyday foods and products and clarifies the health effects, safety and practical takeaways for considering both ingredients. Listen to the episode to find out: How gelatin is made The variety of products that contain gelatin and polysorbate 80 Which vaccine contains gelatin made from cows instead of pigs Three reasons religions that do not allow consumption of pig products still support use of vaccines that contain gelatin made from pigs The importance of the chemical structure of polysorbate 80 What micelles are Four types of evidence against the idea that polysorbate 80 causes fertility issues Check out the video version on YouTube. To learn more about gelatin, please visit https://bit.ly/vec-gelatin. To learn more about polysorbate 80, please visit https://bit.ly/polysorbate-80. Questions? Submit the VEC Vaccine Notes form, https://bit.ly/contact-vec-vaccine-notes. To learn more about vaccine ingredients, please visit https://bit.ly/vec-vax-ingredients. For other vaccines, diseases or general questions about vaccines, check out https://vaccine.chop.edu/. Subscribe to our Parents PACK newsletter, https://bit.ly/3KfLUoO.

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Listen to “VEC Vaccine Notes,” a video and podcast series presented by the Vaccine Education Center at Children's Hospital of Philadelphia. Each episode offers vaccine information in a convenient format, so families have the answers they need to make informed decisions, including details and context that addresses what they may have heard in the news or in conversation with others. This podcast is for general informational and educational purposes only and is not to be considered as professional medical advice for your personal health or for your family's personal health. You should not use it to replace any relationship with a physician or other qualified healthcare professional. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult your physician or, in serious cases, seek immediate assistance from emergency personnel. Clinicians must rely on their own informed clinical judgment in making recommendations to their patients. ©2026 The Children’s Hospital of Philadelphia.

Information

  • Creator
    Vaccine Education Center at Children’s Hospital of Philadelphia
  • Years Active
    2025 - 2026
  • Episodes
    44
  • Rating
    Clean
  • Copyright
    © Copyright 2025 All rights reserved.
  • Show Website
    VEC Vaccine Notes

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