This article is republished from The Conversation under a Creative Commons license.
Misunderstandings about flu vaccines have existed for decades, leading to vaccine mistrust and lower-than-ideal vaccination rates. Now that a coronavirus vaccine appears to be close, experts are concerned that the lack of trust and understanding about flu vaccines could translate into lower-than-optimal coronavirus vaccination rates.
In fact, recent surveys suggest that many Americans would not get vaccinated for COVID-19; a Pew Research Center study released in September reported that nearly half definitely or probably would not. The persistence of anti-vaccine sentiment, partly based on mistrust of vaccine ingredients, is likely contributing to the hesitancy.
The lack of trust is especially upsetting to public health officials, doctors and other scientists. The issue is especially irksome because a major reason for vaccine reluctance sprang from a debunked, retracted and outright false article.
Even though the study was discredited a decade ago, undoing the damage has been difficult. The event showed how easy it is to disseminate incorrect information, particularly over the internet.
As drug information pharmacists, we want to review the ingredients that have caused so much controversy—and to remind you this is a great time to get your flu vaccine. As coronavirus cases soar, threatening not only lives but also the ability of hospitals to care for them, getting a flu vaccine is a crucial part of self-care and health care.
Flu Vaccines 101
The flu vaccine is different every year; that’s because there are different types of viruses and strains of each virus. The contents of the vaccine depend on the kind of flu that has been circulating in any given year.
The FDA Vaccines and Related Biological Products Advisory Committee determines a vaccine for the coming flu season, using the best scientific evidence at hand to determine which virus strains should be included.
To mass-produce the flu vaccine, a large amount of virus needs to be replicated. Vaccine manufacturers do this in eggs or in animal cell lines from which the virus can be harvested. The final product may contain trace amounts of egg protein. Even individuals with egg allergies can usually receive these vaccines; however, for those with severe allergy to egg proteins, flu vaccines that don’t contain egg protein are available.
Inactivating the Virus
Flu vaccines carry a killed, or dead, version of the virus. In turn, the body mounts an immune response, but the vaccine cannot cause the flu because the virus is killed.
One flu vaccine administered as a nasal spray—FluMist—does contain a weakened form of the live virus. In healthy people, this won’t cause the flu, but it can cause runny or stuffy nose, headache and sore throat. The live, weakened flu vaccine should not be used if you have a weakened immune system or are caring for someone with a compromised immune system.
Chemical agents are used to inactivate the virus. But the amount of any inactivating agent in the finished flu vaccine is negligible.
One common agent is formaldehyde. Higher levels of formaldehyde are naturally found in fruits. An average apple contains 600 times more formaldehyde than is found in a dose of the flu vaccine.
Keeping the Vaccine Stable
Vaccines also must be stabilized to help maintain the effectiveness of the vaccine in case it is exposed to heat, light or moisture, or if it experiences changes in acidity. Vaccine makers use stabilizers such as sucrose, sorbitol, gelatin and monosodium glutamate (MSG).
All are food ingredients found in almost every kitchen. Sucrose and sorbitol are sugars; gelatin, derived from collagen, is used in Jell-O and gummy bears; monosodium glutamate adds flavor to many dishes. And the amount of stabilizer found in flu vaccines is very small. The average person consumes much more of these ingredients per day through normal food consumption. For example, the amount of sugar and gelatin in a vaccine dose is far less than that found in a single gummy bear. And for those with gelatin allergies, a flu vaccine without it is easy to find.
Different formulations of the flu vaccine contain a variety of ingredients, but most are in extremely small quantities. They are unlikely to produce negative effects when administered as a single dose once a year. Unless a person has a history of a severe allergic reaction to an ingredient, most flu vaccines can be safely administered.
Centuries ago, the father of toxicology, Paracelsus, said, “What is there that is not poison? All things are poison and nothing is without poison.” Water is healthy for us in appropriate amounts, but too little or too much of it could potentially lead to death. It’s the dose, says Paracelsus, that determines whether or not something is dangerous. Centuries later, consider that sage advice when you think about whether or not to take the flu vaccine.
Terri Levien, Professor of pharmacy, Washington State University
Anne P. Kim, Clinical assistant professor, Washington State University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
