As we fight to end the COVID-19 pandemic, the development and distribution of vaccines have become crucial to achieving herd immunity. But, have you ever wondered about what these vaccines contain? As the world focuses on getting vaccinated, it’s important to understand the ingredients that are commonly included in human vaccines. From adjuvants to preservatives and stabilizers, this blog will explore the components that make up some of the most widely used vaccines. Whether you’re curious about the science behind vaccines or simply want to learn more about what goes into them, this article will provide a comprehensive overview of the common ingredients you’ll find in human vaccines.
Introduction to vaccine safety and efficacy
The introduction to vaccine safety and efficacy highlights the critical need for vaccines to be demonstrated safe and effective before being used in healthy individuals. The FDA evaluates vaccines through a rigorous development program that includes animal studies and human clinical trials. Additionally, the FDA continuously monitors vaccine safety after approval. This ensures that the over one billion doses of vaccines manufactured worldwide each year are safe and effective for healthy babies, children, and adults. [1][2]
Purpose of vaccine ingredients
Each ingredient in a vaccine serves a specific purpose. They are carefully chosen to make the vaccine as safe and effective as possible. Some ingredients help provide immunity against a specific disease, while others help keep the vaccine safe and long-lasting. Ingredients like stabilizers and preservatives are used during the production of the vaccine to make sure it stays free of outside germs and bacteria. All vaccine ingredients serve a specific purpose, making vaccines an essential tool in protecting us against diseases. [3][4]
Common stabilizers in vaccines
Common stabilizers found in some vaccines include sugars and gelatin, which are naturally found in the body and in foods like Jell-O. These stabilizers help keep vaccines effective after manufacturing by preventing contamination and maintaining potency for a longer time. Vaccines only use the necessary ingredients to ensure their safety and efficacy. [5][6]
Aluminum salts as adjuvants in vaccines
Aluminum salts such as aluminum hydroxide, aluminum phosphate, and aluminum potassium sulfate have been used in vaccines for more than 70 years as adjuvants. Adjuvants enhance the immune response of vaccinated individuals, making protection against disease stronger and last longer. Vaccines containing adjuvants are tested for safety and effectiveness in clinical trials before they are licensed for use and are continuously monitored by CDC and FDA once they are approved. Aluminum-containing adjuvants have a demonstrated safety profile of over six decades of use and have only uncommonly been associated with severe local reactions. [7][8]
Formaldehyde and virus growth in vaccine production
Formaldehyde, a commonly known substance used in everyday products such as building materials and household cleaners, is also used in some vaccine production to weaken or kill viruses, bacteria, or toxins. However, only a very small amount remains in the final vaccine product, and any residual quantities are far below levels that could pose a safety concern. The FDA and other regulatory agencies have strict guidelines on safe levels of formaldehyde in vaccines. [9][10]
Presence of egg proteins in some vaccines
Some vaccines, such as influenza and yellow fever, contain egg proteins in their final products since they are made using fertilized chicken eggs. This can pose a problem for individuals with egg allergies, as the proteins can cause allergic reactions. However, advances in technology have reduced the quantities of egg proteins in current influenza vaccines, making them safe for people with egg allergies in most cases. Two new influenza vaccines are also available for use in individuals with egg allergies. [11][12]
Antibiotics in vaccine production
Certain antibiotics are used in the production of vaccines to prevent bacterial contamination. However, only small amounts of antibiotics are used, and the ones that are most likely to cause severe allergic reactions, such as penicillin, are not used. Examples of antibiotics used include neomycin, polymyxin B, streptomycin, and gentamicin. The presence of antibiotics in vaccines is unlikely to cause harm, as they are present in very small amounts or are undetectable. [13][14]
Thimerosal in multi-dose flu vaccines
Thimerosal, a mercury-based preservative, has been used in multi-dose vials of vaccines for decades to prevent the growth of bacteria and fungi. The human body eliminates thimerosal easily, and there is no evidence of harm caused by the low doses found in vaccines. However, as a precautionary measure, thimerosal was reduced or eliminated in vaccines in 1999. Currently, multi-dose flu vaccines are available in both thimerosal-containing and thimerosal-free versions. [15][16]
Different types of vaccines and how they work
Different types of vaccines work in different ways to teach the immune system how to fight off certain germs and diseases. Inactivated vaccines use the killed version of the germ, while live-attenuated vaccines use a weakened form of the germ. Subunit recombinant polysaccharide and conjugate vaccines use specific pieces of the germ, and toxoid vaccines use the toxin produced by the germ. Messenger RNA vaccines make proteins to trigger an immune response, while viral vector vaccines use a modified version of a different virus to deliver protection. [17][18]
FDA-approved vaccines and ingredients
The FDA requires that vaccines undergo a rigorous development program to determine their safety and effectiveness. Each ingredient in a vaccine serves a specific purpose, such as providing immunity or keeping the vaccine safe and long-lasting. Some vaccines include aluminum salts as an adjuvant, which has been shown to have a safe profile in medical studies. Other adjuvants used in FDA-approved vaccines include AS04 and CpG 1018. Antibiotics are used in some vaccine production to prevent bacterial contamination, but only small amounts are present in the final product. Common vaccine ingredients include antigens, stabilizers, and cell culture materials. [19][20]
