What Are The Possible Benefits Of Recombinant Flu Vaccines
Because recombinant flu vaccine is not dependent on an egg supply, the recombinant influenza vaccine manufacturing process might be faster than that of egg-based vaccines in the event of a pandemic or shortage of the eggs needed to grow influenza viruses. This process is not limited by the selection of vaccine viruses that are adapted for growth in eggs. It also avoids mutations that can occur when viruses are grown in eggs, which can sometimes affect how well the finished vaccine works. A 2019 study in Hong Kong showed that recombinant flu vaccination resulted in a greater antibody response in adults 65 and older compared to traditional flu vaccines. Although increased antibody response following flu vaccination does not guarantee better clinical protection, additional studies to determine the possible benefits of recombinant flu vaccines in this age group are warranted.
Safety And Side Effects
The inactivated flu vaccine does not contain the live virus and cannot cause flu. Flu vaccines have a very good safety record. The most commonly reported side effects of flu vaccines are:
- pain, swelling, bruising, hardness or redness at the injection site
- slightly raised temperature
- feeling generally unwell
A higher rate of these common side effects has been reported with Fluad, an adjuvanted trivalent vaccine which was recommended for people aged 65 and over in previous years. This year, Fluad Tetra is being offered to people aged over 65, which also uses an adjuvant. Side effects usually last 1-2 days.
There are several different makes of flu vaccine available each year. For more information on side effects, ask for the Patient Information Leaflet for the vaccine you are offered. Additional information about vaccine side effects, anaphylaxis and adverse reactions can be found here.
What Is Recombinant Flu Vaccine
Recombinant influenza vaccines are produced using recombinant technology. This method does not require an egg-grown vaccine virus and does not use chicken eggs in the production process.
Recombinant flu vaccine was first licensed by the FDA in the United States in 2013. Currently, the recombinant flu vaccine and the cell culture-based flu vaccine are the only egg-free flu vaccines licensed for use in the United States.
There is one quadrivalent recombinant flu shot available for the 20212022 influenza season.
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Why Is There Egg In Some Flu Vaccines
The most common way flu shots are made is by using eggs in the production process. The CDC or another World Health Organization partner provides private manufacturers with selected flu viruses, which are then injected into fertilized chicken eggs so the viruses can multiply.
After several days, fluid containing the viruses is taken from the eggs. The viruses are then processed in different ways depending on the type of flu vaccine thats being made.
As you can imagine, many chicken eggs are required to produce vaccines this way, and it can take some time to grow the flu viruses. To make this process more efficient, manufacturers have developed newer methods that dont involve eggs at all. More on this below.
What’s An ‘attenuated’ Or Weakened Flu Vaccine
There is one kind of flu vaccine that does contain a livebut weakenedvirus. That’s the nasal mist, which is available for non-pregnant people age 2 to 49 with no serious underlying health conditions.
For this vaccine, the CDC explains that the viruses are first grown in eggs just as they are for the injection. But then instead of being killed, the viruses go through a different production process that weakens them. According to the CDC, “The weakened-viruses are cold-adapted, which means they are designed to only multiply at the cooler temperatures found within the nose, and not the lungs or other areas where warmer temperatures exist.”
“It’s a miracle of modern science,” says Dr. Schaffner. “The viruses are engineered on a molecular level, so they can’t multiply at the higher temperature that’s just a tiny bit higher in the lung compared to the nose. The viruses are incapable of multiplying at that temperature, so they can’t produce influenza at all.”
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Novel Platform For Growing Virus To Make Vaccine On Par With Traditional Egg
byCrystal Phend, Contributing Editor, MedPage Today October 13, 2021
Flu vaccine generated with a novel platform, using animal cell culture rather than egg, appeared to have good protection for children, a clinical trial showed.
Among kids ages 2 and up, the IIV4c vaccine had 54.6% efficacy in preventing laboratory-confirmed influenza compared with a non-influenza vaccine as a stand-in for placebo .
Adverse events were similar between groups, and efficacy was similar across age groups and prior influenza vaccination status, reported Alexandre C. Fortanier, PhD, of Seqirus Clinical Development in Amsterdam, and colleagues in the New England Journal of Medicine.
These findings extended the evidence for efficacy seen in a prior trial with the cell-culture-derived trivalent inactivated influenza vaccine in adults, they noted.
The cell-based IIV4c vaccine gained expanded FDA approval on October 15 for use down to age 6 months under the same Flucelvax Quadrivalent name as the conventional version using standard propagation technology.
The new propagation technique uses a Madin-Darby canine kidney cell line, which had been hoped to actually improve efficacy. “Egg-adaptive mutations in the globular head of the hemagglutinin protein in egg-based vaccine viruses may contribute to observed low vaccine effectiveness,” the researchers noted. “Genetic changes can be avoided through the use of manufacturing platforms that do not rely on eggs.”
Evergreen Flu Vaccine Ingredients: The Preservatives And Additives
Beyond the three to four viral components, a number of additives and preservatives are required to make vaccines effective and to keep them from going bad. These ingredients, sometimes covered as trade secrets by drug companies in less public drugs, have led to many a conspiracy theory that anti-vaxxers would have you latch onto. Its really much more boring than that.
Here are some of the ingredients you will find in the 2021-2022 flu vaccine and why theyre there.
The Ingredient: Aluminum Salts
Use: Boosts bodys response to the vaccine
The Ingredient: Sugar or gelatin
In: Most vaccines
In: Few flu vaccines only multi-dose vials
The CDC says: Thimerosal has a different form of mercury than the kind that causes mercury poisoning . Its safe to use ethylmercury in vaccines because its processed differently in the body and its less likely to build up in the body and because its used in tiny amounts. Even so, most vaccines do not have any thimerosal in them.
The Ingredient: Egg proteins
In: Some vaccines
Use: Growing the vaccine
The CDC says: Because influenza and yellow fever vaccines are both made in eggs, egg proteins are present in the final products. However, there are two new flu vaccines now available for people with egg allergies.
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Types Of Flu Vaccines
The flu vaccines for the 2021-2022 season are quadrivalent formulations, meaning that they protect you from four strains of the flu virus. The strains included in each year’s flu vaccine are determined based on which strains are most likely to be circulating and making people sick.
There are different ways to get the flu vaccine:
- Injected with a needle into the arm muscle
- Nasal spray
- A jet injector using a high-pressure, narrow stream of liquid to penetrate the skin without a needle
Flu vaccines are produced in several different forms:
- Live attenuated virus grown in an egg-based material
- Inactivated virus grown in an egg-based material or cell culture
- Vaccines manufactured with synthetic material that uses recombinant technology
Some forms of the vaccine are available in more than one way of delivery. Check with your healthcare provider to determine which vaccine is available to you.
There are different brands of flu vaccines, which you may see at your doctors office or pharmacy.
|Flu Vaccines for 2021/2022 Season|
Can You Get The Flu From The Flu Shot
No, you cannot get the flu from the flu vaccines. Flu vaccines given with a needle are made with either inactivated viruses, or with only a single protein from the flu virus. The nasal spray vaccine contains live viruses that are weakened so that they will not cause illness.
While some people may experience a low-grade fever or body aches as a side effect, that does not mean the vaccine gave them the flu. For example, if you got sick with the flu shortly after receiving a flu vaccine, it means you were exposed to the flu before your body had the chance to fully develop the antibodies needed. It takes about two weeks after receiving the vaccine before you’re protected against the influenza virus.
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Flu Shots And Egg Allergies
The Centers for Disease Control and Prevention recommends that everyone ages six months and older should get an annual flu shot. However, people with egg allergies need to take special precautions, since almost all influenza vaccines are cultured in chicken eggs.
There’s one flu vaccineFlublok, made by Protein Sciences Corporationthat does not use chicken eggs during manufacturing. Flublok is approved for anyone ages 18 and up, so if you’re allergic to eggs and fall into that age range, you should ask specifically for Flublok.
For children and teens under age 18 with egg allergy, the CDC urges them to get the regular flu shot, but only under the direct care of a healthcare provider with expertise in handling severe allergic reactions. Read more about whether people with egg allergies should get the influenza vaccine.
Comparing 5 Vaccine Formulations
The retrospective cohort study included more than 13 million seniors ages 65 and older who received one of five flu vaccine formulations last season: Flucelvax , egg-based quadrivalent , egg-based high-dose, adjuvanted, and standard-dose vaccines. The last three versions are all trivalent .
Though an earlier study suggested that the cell-based recombinant vaccine produced in insect cells was more effective than standard egg-based vaccines, it wasn’t evaluated in the study, because it wasn’t used in enough Medicare recipients to allow analysis. The cell-based vaccine the researchers did analyze contained a cell-cultured H3N2 vaccine strain component for the first time last season, though the 2009 H1N1 and influenza B vaccine viruses were produced from egg-adapted viruses.
Of the seniors who were vaccinated through the end of January, 5% got cell-cultured quadrivalent, 14% egg-based quadrivalent, and 63%, 11%, and 7% received the high-dose, adjuvanted, and standard-dose trivalent, respectively.
To gauge differences in how well all versions performed against each other, the main factor the researchers looked at was their impact against flu-related hospitalizations and emergency room visits.
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Benefits And Challenges Of A Plant
There are some clear benefits to developing plant-based vaccines. Kozak says plant-based vaccines are cheaper to produce than many conventional vaccine production methods.
Ward says plant-based vaccines are also faster to produce than other traditional vaccines. Medicago has also developed a plant-based flu vaccine that is under review with Health Canada. The company says it takes five to six weeks to produce it compared to the five to six months it takes using egg-based production meansa process commonly used in vaccines.
Once we understand how effective the plant-based COVID-19 vaccine is in real-world settings, they might be an option for people who need to mix-and-match vaccines, Kozak says.
But Ward says being the first to make a plant-based COVID-19 vaccine has been challenging, too. The team has learned a lotincluding how to figure out how to “lift up and invert hundreds of these little plants” so they can transfer the DNA into their roots. “Nobody’s ever done that before at scale,” he says.
Plants also require certain environmental conditions to grow, including plenty of sunlight. This means not every country may be positioned or have the infrastructure to develop plant-based vaccines at scale.
Rabies Vaccine And Egg Allergies
Rabies is a dangerous virus transmitted through bites from infected animals. Once symptoms begin, the disease is almost always fatal.
There are various different vaccines on the market for rabies that can be administered after you’ve been exposed to the virus. However, most of the vaccines are cultured in chicken embryos and aren’t considered safe for people who have severe egg allergies.
Fortunately, there is one option for the egg-allergic: Imovax, which is not cultured in chick embryos.
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Does The Flu Shot Contains Live Virusor Not
“Many years ago, when we first started getting flu shots, they were live attenuated virus vaccines,” Michael Knight, MD, a primary care physician and assistant professor of medicine at George Washington University Medical Faculty Associates in Washington, DC, tells Health.“So if the patient was pregnant or had a weakened immune system, we couldn’t give that to them,” he says.
But that’s no longer the case. Today’s flu shots are inactivated, meaning the virusesor viral parts–in this type of vaccine can’t possibly infect anyone because they’re not alive. These are the shots that the majority of adults receive each season.
“The flu shots you get do not have a live virus that could cause infection,” says Dr. Knight.
There’s one exception: a nasal mist flu vaccine is made with live, “attenuated” viruses, says the US Centers for Disease Control and Prevention . The viruses weakened but not killed. Still, they cannot cause influenza, says CDC.
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What Were The Results Of The Clinical Trials Using Cell
A clinical trial of the previous trivalent formulation of Flucelvax demonstrated effectiveness and safety among persons 18 through 49 years old. In immunogenicity studies among people 18 years and older and 4 through 17 years old, Flucelvax Quadrivalent was found to produce a similar immune response to the trivalent formulation. Post-vaccination symptoms were typical of those seen with other injectable flu vaccines.
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Safety And Possible Side Effects
The CDC, U.S. Food and Drug Administration , National Institutes of Health , American Academy of Pediatrics , Advisory Committee on Immunization Practices , and National Academy of Sciences’ Institute of Medicine have all declared that the use of thimerosal in vaccines is safe and effective.
The safety profile of traditional and preservative-free flu shots are considered equal. Possible side effects of both thimerosal-containing vaccines and preservative-free vaccines include:
- Pain and swelling at the injection site
- Low-grade fever
Side effects are typically mild and resolve within a day or two.
However, if you develop wheezing, difficulty breathing, vomiting, rapid heartbeat, loss of consciousness, or swollen lips, tongue, or throat, call 911 or go to your nearest emergency room. These could be the signs of a rare and potentially life-threatening allergic reaction known as anaphylaxis.
Why Do Flu Vaccines Cause Side Effects
All vaccines can cause side effects, and the vast majority of these symptoms are completely normal. “Side effects are basically telling you that your immune system is working,” says Michael Knight, MD, a primary care physician and assistant professor of medicine at George Washington University Medical Faculty Associates in Washington, DC. “The immune cells are rushing to where the vaccine was injected to react to it.” Local soreness at the site of the injection, in fact, is the most common side effect after any vaccine jab.
Flu shots have been around since the 1930s and are considered extremely safe. According to the US Department of Health and Human Services , most side effects of the flu vaccine are mild and go away in a few days.
Read on to find out what you might experience after you get your flu shot. For the vast majority of people, none of these possibleand mostly mild or rareside effects are reasons not to be protected against influenza.
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Should My Child With An Egg Allergy Get The Flu Shot
An egg allergy is the second most common food allergy in the U.S. after a milk allergy. Egg allergies affect about 1.3% of all children and 0.2% of all adults.
Some signs or symptoms of an egg allergy include:
- Tight, hoarse throat, or trouble swallowing
- Swelling of the tongue, affecting the ability to talk or breathe
- Vomiting or stomach cramps
- Pale or blue coloring of skin
- Dizziness or feeling faint
- Anaphylaxis a potentially life-threatening reaction that can impair breathing and send the body into shock
If your child has an egg allergy, the Centers for Disease Control and Prevention recommends flu vaccination. If your child has a severe allergic reaction to egg, your child should be vaccinated in a medical setting under the supervision of a health care provider who can recognize and manage severe allergic conditions.
The risk of adverse reaction to flu vaccination in people with an egg allergy is low, with 10 cases of anaphylaxis in 7.4 million doses of the flu vaccine, according to the CDC. Most cases of anaphylaxis were not related to the egg protein present in the vaccine.
However, if your child has had a previous severe allergic reaction to the flu vaccine, a flu vaccination is not recommended, according to the CDC.
The best way to prevent flu is by getting vaccinated each year.
Adela Taylor, M.D., is an allergist in Eau Claire and Rice Lake, Wisconsin.
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In Australia, vaccination for certain groups of people is funded under the National Immunisation Program .
To get the cell-based jab in Australia, patients need to specifically request it from their GP, and as it’s not funded under the NIP, it’s likely to set someone back about $40.
Vaccines using traditional egg-based technology have between 70 per cent and 90 per cent strain-specific effectiveness in healthy adults, and are free for those eligible under the NIP.
Professor Booy said the US started using cell-based flu vaccines about 10 years ago, and it was “about time” Australia caught up.
“A hundred million people in the US have had the vaccine, so we know it works and we know its safe,” he said.
Dr Pearce said in the next five years, he would expect cell-based technology to be “standard” for the flu jab in Australia.
“We would expect that we will move away from making them in eggs to making them more cellular based,” he said.
Jonathan Anderson, the medical director from Seqirus, the company behind the cell-based jab, said they had been upscaling the manufacturing process to meet the potential demand.
“It’s taken a while for us to improve the manufacturing so that we could produce the quantities that might be required in a country like Australia,” he said.
“Now we’re able to have a consistent supply.”
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