Sunday, June 4, 2023

Do Vaccines Always Prevent Disease

Effective Therapeutic Vaccines: The Barriers

How do vaccines prevent disease?

While researchers have worked hard at developing therapeutic vaccines for decades, the results have tended to be disappointing.

“Unfortunately, the role of immunity in diseases like cancer is much more complicated than we are smart,” says Wasserman. “There are a lot of interesting observations to suggest that therapeutic vaccinations might work, and we’ve learned a lot in forty years of researching them. But we still have a long way to go.”

Some researchers think that part of the problem is that diseases like HIV create such high levels of virus in the blood that the immune system is quickly overwhelmed. Experts hope that lowering the viral load first and then using a therapeutic vaccine could make for better results.

Wasserman observes another risk. Standard vaccines help your immune system target foreign invaders, but when you’re dealing with a disease like cancer, the tumor cells are very similar to normal healthy cells, creating a new danger.

“A cancer vaccine might not be able to distinguish between cancer cells and normal healthy cells,” says Wasserman. “It could wind up attacking both of them, causing an autoimmune disorder.”

Ertl stresses that therapeutic vaccines will never be a substitute for preventative vaccines.

“If you have a choice between a preventative vaccine and a therapeutic vaccine, I would always recommend prevention,” says Ertl. “Preventing a disease is always easier and safer than treating it.”

Therapeutic Vaccines: Keeping Perspective

While therapeutic vaccines are exciting, none is close to being used outside of clinical trials. So if you or a loved one is sick now, you need to rely on other treatments. You could also talk to your doctor about taking part in a clinical trial.

But Ertl says that, in the future, therapeutic vaccines could be crucial for diseases that we learn how to treat but not prevent.

“There are some diseases, like Alzheimer’s, that we just don’t have a clue how to prevent with a vaccine,” she says. A preventative vaccine might be unlikely or impossible, while a therapeutic vaccine could be more feasible.

Researchers are making progress, says Ertl, but there’s still a lot to learn.

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Where Can I Get Vaccinated

The best place to go for vaccinations is your family medical clinic. They have your medical records and can check to see if youve already had a particular vaccination. Either your doctor or a nurse can give the vaccination.If you dont have a family doctor, you can go to one of the after-hour medical clinics. Phone them first to make sure they can help you with the vaccination you need.You can find a clinic near you on the Healthpoint website. Put in your address and region, and under Select a service, click on GPs/Accident & Urgent Medical Care.Vaccines on the National Immunisation Schedule are free. Other vaccines are funded only for people at particular risk of disease. You can choose to pay for vaccines that you are not eligible to receive for free.

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Are There Any Risks To Being Vaccinated

Most reactions to vaccines are mild, such as fever or redness at the injection site. These reactions show that your immune response is building and the vaccine is working. If you are worried, contact your doctor straight away.Very rarely, a serious allergic reaction can happen. This is treatable and occurs soon after the injection. This is why you must wait at the doctor’s clinic for 20 minutes after vaccination. Read more about comparison of possible disease complications and vaccine responses and learn more about side effects from vaccines.

Why Didnt Clinical Trials Track Infections

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The clinical trials testing vaccines from Moderna, Pfizer-BioNTech, and Johnson & Johnson measured each vaccines ability to prevent serious disease, not its ability to block transmission of the virus.

Frankly, transmission wasnt the primary concern at that point of the trials, Kindrachuk says. It was to make sure people werent getting sick.

With thousands of people being hospitalized and dying every day, the first priority was to measure whether a vaccine prevented severe disease and death. While researchers recognized that it was important to measure whether vaccines prevented asymptomatic infection, doing that was very difficult and costly, Dean says. So researchers tracked symptomatic infections instead. That left unanswered the question of whether any vaccinated people without symptoms could have an asymptomatic infection.

There were some questions about whether you could still have virus in your nose and still be infectious, Dean says.

Even a tiny amount of virus in a vaccinated person might present a risk to others.

We dont have a good idea of what the infectious dose is for somebodyhow much virus you have to be exposed to to get infected, Kindrachuk says. Its not about the one dose you get in a single moment, but the accumulation over minutes to hours.

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Benefits At The Individual Level

Infectious diseases used to be the main cause of death for children. Infectious diseases, such as polio, also often caused disability in children. Adults died of diseases such as tuberculosis. Many infectious diseases have been dangerous for groups such as older people and pregnant women.

Even today, an infectious disease can be serious in itself as it can cause severe secondary diseases and permanent injury or even death.

Vaccination can completely prevent developing an illness. While vaccination cannot always completely prevent an infection, it can provide protection against the most serious forms of disease.

Personal vaccination protection gains prominence when

  • a vaccine prevents developing a serious disease but does not prevent infection or infectivity
  • a vaccine is used to prevent a disease that is not transmitted from one person to another, such as tetanus.

While vaccination usually provides good and long-term immunity, it does not necessarily give total protection. The individual protection provided by vaccination depends on a variety of factors. It is influenced by the characteristics of the pathogen, the vaccine and the vaccine recipient. Sometimes a vaccinated person may become ill despite the vaccination, but the symptoms are usually less severe in such cases.

Vaccination can be used to reduce suffering related to illness.

What Diseases May Therapeutic Vaccines Treat

The number of diseases researchers hope to treat with therapeutic vaccines is enormous.

“Someday, we might make vaccines for Alzheimer’s, neurological diseases, arteriosclerosis, and maybe even obesity,” says Ertl. Other targets for therapeutic vaccines include viruses like herpes and hepatitis and even nicotine addiction.

The list of diseases is impressive, but Ertl and other experts say that most of these vaccines are in very early stages of development. Here are a few examples of therapeutic vaccines being studied.

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Early Data Looked Promising

Although the vaccine manufacturers did not track infections for all phase three trial participants, they did gather some data. Moderna tested all participants when they received their second dose and reported in December that fewer asymptomatic infections occurred in the vaccinated group than the placebo group after the first dose. Johnson & Johnson also reported data from nearly 3,000 phase three trial participants who were tested two months after vaccination to see if they had antibodies from a new infection since vaccination. That preliminary data suggested a 74 percent reduction in asymptomatic infection.

Those findings hinted that the vaccines had the ability to prevent infections. That development was followed by three preprintsnot yet peer-reviewedthat suggested even more good news. One found that people vaccinated with one dose of the Pfizer-BioNTech vaccine had viral loads up to 20 times lower than viral loads in unvaccinated, infected people.

Two others, from the Mayo Clinic and the U.K., included more than 85,000 routinely tested healthcare workers who were fully vaccinated with the Pfizer-BioNTech vaccine. The vaccine reduced infection by 85 to 89 percent. All this evidence underscores all three vaccines ability to prevent infection in the majority of those vaccinated.

What Is In Vaccines

How do vaccines prevent disease?

Depending on the infection, ingredients in vaccines can vary. They may also change from year to year as new strains of viruses appear. Some vaccines may contain a small dose of:

  • A live germ.
  • Dead germs.
  • Small parts of germs .
  • Inactivated toxins produced by bacteria.
  • Antibiotics or preservatives to stop the vaccine from becoming contaminated or going off.
  • Diluents .

Alternatively mRNA vaccines teach our cells how to make a protein that stimulates an immune response.

Australia has strict rules on vaccine safety. Before a vaccine is registered by the Therapeutic Goods Administration and made available to the public it goes through rigorous testing. And, even when it is used, it is constantly monitored for safety and effectiveness.

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What Is A Vaccine Schedule

A vaccine, or immunization, schedule lists which vaccines are recommended for different groups of people. It includes who should get the vaccines, how many doses they need, and when they should get them. In the United States, the Centers for Disease Control and Prevention publishes the vaccine schedule.

It’s important for both children and adults to get their vaccines according to the schedule. Following the schedule allows them to get protection from the diseases at exactly the right time.

Vaccines Do Not Cause Allergic Diseases

Like autoimmune diseases, allergic diseases such as asthma have become more common in the developed world over the past 30 years. However, there is no significant evidence that vaccines cause allergic diseases in otherwise healthy people.

Generally, for every 100,000 doses of a vaccine, less than 1 person will experience a severe allergic reaction after receiving ita rate that is extremely low.43 Nevertheless, people with a history of reactions to a specific vaccine or vaccine additives, or a strong family history of allergic disease, should always take precautions.

Injectable vaccines used in Australia do not contain detectable amounts of antibiotics such as penicillin or sulphonamides to which some people may be allergic. The hepatitis B vaccine is grown in yeast. Although there have been some isolated reports of possible severe allergic reactions to this vaccine, the benefits of receiving the vaccine far outweigh the multiple risks associated with hepatitis B infection.

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Rapid Response To Risks Associated With Vaccines

If a potential problem with a vaccine is detected, the use of that vaccine may be temporarily paused. This allows health authorities to investigate whats caused the problem and whether it can be linked to a particular batch of the vaccine. For example, young children given a particular influenza vaccine in Australia in 2010 showed an increased risk of febrile seizures. When the problem first became apparent, the use of all influenza vaccines in young children was suspended to allow authorities to identify the one type of vaccine preparation causing the problem. Then, influenza vaccines shown not to be associated with unacceptable rates of febrile seizures were reintroduced to ensure that protection against influenza remained available for children at high risk of complications from the disease.

When Should You Get Vaccinated

Vaccines and the diseases they prevent

The National Immunisation Schedule has a list of free vaccinations for different ages. Vaccinating on time gives the best protection. Missing or late vaccinations can put your family/whnaus health at risk.

Most vaccines are given to babies and children to build up their immunity. Vaccination starts at 6 weeks old. Other vaccines are recommended for people who are at greater risk of certain diseases, such as people with a weakened immune system because of illness or the medicines they are taking, the elderly or people who are travelling overseas where certain diseases are more common.

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Vaccines: Who Should Avoid Them And Why

  • advises certain individuals not to get specific vaccines.
  • Different vaccines have different components. Each vaccine can affect you differently.
  • Individuals with a compromised immune system are typically advised to wait. People who have experienced allergic reactions to a particular vaccine are generally told to avoid follow-up doses.
  • Centers for Disease Control and Prevention recommend a range of vaccinations for Americans of all ages. These vaccines help prevent dangerous diseases that in the past would sicken countless people each year.

    However, these vaccines may not be right for everyone. The CDC advises that certain people not get specific vaccines, or to wait before getting vaccinated. This is because different vaccines contain different components, and each vaccine can affect you differently. Your age, health conditions, and other factors all combine to determine if you should get each vaccine.

    The CDC has prepared a detailed list of vaccines that specifies who should avoid getting each one and who should wait to get it. Certain individuals with a compromised immune system are typically advised to wait. And people who have experienced allergic reactions to a particular vaccine are generally told to avoid follow-up doses.

    Here are guidelines for those who should avoid or delay some of the more common vaccines.

    You should not get vaccinated for if you:

    People with a history of should discuss the risks of the with their doctor.

    • Mexico

    Wasn’t There A Problem With The Rotavirus Vaccine

    Rotavirus is one of the most common causes of diarrhea in young children. In 1999, a rotavirus vaccine was taken off the market because it was linked to an increased risk for intussusception, a type of bowel obstruction, in babies.

    However, two different rotavirus vaccines are now available and are very safe. Some studies suggest that they have a very small increased risk for intussusception, but that problem is rare. These vaccines have been shown to prevent most cases of rotavirus infection and almost all of the severe cases.

    The vaccine is now on the regular immunization schedule to be given orally to infants as a liquid during standard vaccination visits RotaTeq at ages 2 months, 4 months, and 6 months, or Rotarix at ages 2 months and 4 months. Your doctor will have the most current information.

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    Some Adverse Events Coincide With But Are Not Caused By Vaccination

    Symptoms such as fever, rashes, irritability and nasal snuffles are common, especially among children. Consequently, it can be difficult to determine how many of these reactions are caused by a vaccine when the background rate in the same age group is unknown.

    In some cases, these kinds of reactions may be caused by the vaccine. But in other situations, the symptoms may be unrelated, occurring by chance at the same time as the vaccination. For this reason, scientists refer to these kinds of symptoms as adverse events following immunisation to indicate that the vaccine may not cause events that follow vaccination.

    Many adverse events following a vaccine injection are coincidental.

    Current vaccines used in Australia have fewer side effects than previous vaccines.

    Safety surveillance systems in countries like Australia require health care providers to report adverse events that occur following vaccination, regardless of the cause. The reports are compared with historical trends to identify any changes requiring special investigation and assess whether these adverse events are vaccine-related.

    It can be misleading to rely on the reported numbers of adverse events. Several factors must be considered to determine if an event is coincidental or caused by the vaccine. Many adverse events are coincidental.

    Benefits At The Population Level

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    A comprehensive vaccination programme can be used to reduce infectious diseases and combat epidemics in the population. High vaccination coverage also provides herd immunity for those who have not been vaccinated. For example, this brings benefits to newborn babies and infants whose immunity is not yet as good as in healthy adults.

    In the best-case scenario, vaccinations can be used to fully eradicate a disease from a region or the world. An example of this is smallpox, which was globally eradicated a few decades ago. The vaccine recipients of the past have thus indirectly also provided protection for all children of today.

    Although vaccination always takes place one child at a time, the benefits of vaccination may extend widely both regionally and over time.

    Vaccines have completely or nearly completely eradicated several infectious diseases from Finland, including

    • diphtheria

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    How Effective Are Immunizations

    Vaccines are very effective at preventing disease, but they don’t work all the time. Most of the recommended childhood immunizations are 90%-100% effective, according to the CDC.

    However, for reasons that are not completely understood, sometimes a child will not become fully immunized against a disease after receiving a vaccine. This is all the more reason to get children vaccinated. Children in whom the vaccine is 100% effective protect those few who have not been completely immunized — lessening everyone’s chance of exposure to the disease.

    Even in cases where a vaccine has not given your child 100% immunity, the symptoms — if your child is exposed to an infectious disease — will still usually be milder than if they had not been immunized at all.

    Which Vaccines Do We Need

    Vaccines not only protect us, but vulnerable people in our community .

    The vaccines we may need are determined by our health, age, lifestyle and occupation. Together, these factors are known as HALO.HALO is defined as:

    Check your immunisation HALO using the Immunisation for Life Infographic downloadable poster.

    Remember, if you are not sure about what vaccines you need, talk to your GP . If you find you are not up to date with your vaccinations, your GP will tell you about catch-ups and boosters.

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