Monday, March 20, 2023

What Makes A Vaccine Effective

How Are New Vaccines Developed

What makes the COVID vaccine different than other vaccines and how long is it effective?

It can take a long time to develop a new vaccine. Vaccines go through many phases of development including research, discovery, pre-clinical testing, clinical testing and regulatory approval. Once the vaccine is approved, the vaccine is then manufactured and shipped to where its needed.

In certain circumstances, increased resources, concurrent clinical trials, and funding can fast-track development, such as in the case of the COVID-19 vaccines.

After vaccines are introduced into immunisation schedules, they are closely monitored through trials and surveillance to see if they are effective and safe. In Australia, there are regional and national surveillance systems actively looking for any adverse events following immunisation. This is necessary, as sometimes unexpected side effects occur after vaccines are registered for use.

Some vaccines, such as the flu, need to be updated every year to respond to changing infection strains and conditions. For these updates, the process is compressed to ensure the vaccine is available as needed.

What Are The Covid Vaccine Side Effects

Some people notice side effects of the COVID-19 vaccine, such as pain or swelling where they got the vaccine. You may also get fever, muscle aches, chills, fatigue, headaches or a combination of these symptoms.

COVID-19 vaccine side effects may last about a day or two, and do not signify illness. These are signs that your immune system is responding and preparing to fight the coronavirus if you catch it. If symptoms persist, you should call your doctor.

Do Recent Vaccine Effectiveness Study Results Support Flu Vaccination

The large numbers of flu-associated illnesses and deaths in the United States, combined with the evidence from many studies that show flu vaccines help to protect against flu illness and its potentially serious complications, support the current U.S. flu vaccination recommendations. CDC recommends a yearly flu vaccine as the first and most important step in protecting against flu viruses. Everyone 6 months and older should get an annual flu vaccine, ideally by the end of October.

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How Do Vaccine Effectiveness Studies Differ From Vaccine Efficacy Studies

Vaccine efficacy refers to vaccine protection measured under optimal conditions where vaccine storage and delivery are monitored and participants are usually healthy. Vaccine efficacy is determined in RCTs, usually clinical trials. Vaccine effectiveness measures how well a vaccine works in real-world conditions. Differences in real-world conditions compared to the tightly controlled conditions in clinical trials can influence how well a vaccine works. Vaccine effectiveness studies include people with underlying medical conditions who have been administered vaccines by different health care providers. Vaccine effectiveness studies can be used to determine if higher risk groups of people respond differently to the vaccine. Vaccine effectiveness studies can also determine if different flu viruses that are circulating and evolving in real-world conditions affect vaccine performance. Lastly, vaccine dosing schedules or vaccine storage and handling requirements may not be followed as closely in the real world as in clinical trials therefore, vaccine effectiveness studies can be conducted to account for how these factors affect vaccine performance. Results from vaccine effectiveness studies are subject to biases that do not occur in vaccine efficacy studies, like selection bias and confounding, which is why licensure of vaccines depends upon data collected in RCTs.

One More Thing About Your Immune Response

These 7 Conditions Make the Pfizer Vaccine Less Effective ...

Early on, as vaccines were being tested, and as the medical community learned more about COVID-19 from people who were in recovery, there were concerns about how long the body still produced antibodies after overcoming the infection. Basic long-standing scientific research addresses this.

As time passes, the bodyâs T-lymphocytes and B-lymphocytes remember the virus and regenerate the antibodies in the future should the virus show up again. While we are still collecting a tremendous amount of information about the COVID-19 vaccine as well as the coronavirus in general, there is no reason to believe this natural immune response isnât occurring today in those who are being vaccinated and those who have already overcome the virus.

There are data, however, to support that those who have been infected and recovered from COVID-19 have less of an immune response than those who have never been infected and should, therefore, still be vaccinated.

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Vaccine Protection And Timing

Vaccines offer strong protection, but that protection takes time to build. People must take all the required doses of a vaccine to build full immunity. For two-dose vaccines, vaccines only give partial protection after the first dose, and the second dose increases that protection. It takes time before protection reaches its maximum level a few weeks after the second dose. For a one-dose vaccine, people will have built maximum immunity against COVID-19 a few weeks after getting vaccinated.

How Does Cdc Measure How Well The Vaccine Works

Scientists continue to work on better ways to design, conduct and evaluate non-randomized studies to assess how well flu vaccines work. CDC has been working with researchers at universities and hospitals since the 2003-2004 flu season to estimate how well flu vaccine works through observational studies using laboratory-confirmed flu as the outcome. These studies currently use a very accurate and sensitive laboratory test known as real-time RT-PCR to confirm medically attended flu virus infections as a specific outcome. CDCs studies are conducted in sites located across the United States to gather data that accurately represents people and conditions across the country. To assess how well the vaccine works across different age groups, CDCs studies of flu vaccine effects have included all people aged 6 months and older recommended for an annual flu vaccination. Similar studies are being done in Australia, Canada and Europe.

  • Baylor Scott and White Health
  • Columbia University Irving Medical Center
  • HealthPartners
  • Intermountain Healthcare
  • Kaiser Permanente Northern California
  • Kaiser Permanente Northwest
  • Regenstrief Institute
  • University of Colorado .

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How Do We Measure How Well Flu Vaccines Work

Two general types of studies are used to determine how well flu vaccines work: randomized controlled trials and observational studies. These study designs are described below.

Randomized controlled trials

Observational Studies

The second type of study is an observational study. There are several types of observational studies, including cohort and case-control studies. Observational studies measure vaccine effectiveness by assessing how well flu vaccines work among different groups of people, in different settings, and in different real-world conditions that exist outside of randomized controlled trials . Vaccine effectiveness is measured by comparing how often people in the vaccinated and unvaccinated groups get flu. Vaccine effectiveness is the percent reduction in the frequency of flu illness among vaccinated people compared to people not vaccinated, usually with adjustment for factors that are related to both flu illness and vaccination .

Which Vaccines Do We Need

Novavax COVID-19 Vaccine May Be Highly Effective, Clinical Trials Show

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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How Successful Are Vaccines

Vaccination is the most effective preventative measure against infectious diseases. Most vaccine-preventable illnesses are highly contagious, spread quickly and can cause severe complications which may impact on our quality of life.

Vaccines give us immunity without us getting sick. They also protect vulnerable people in our community who cannot be immunised such as very young children or those who are too sick.

When enough people in the community are vaccinated, the spread of a disease slows down or stops completely. So as long as enough people are vaccinated, diseases will not spread. We call this herd immunity or community immunity. The percentage of people who need to be immune in order to achieve herd immunity varies with each disease. For example:

If Older People Have Weaker Immune Responses To Flu Vaccination Should They Still Get Vaccinated

Despite the fact that some older adults have weaker immune responses to the influenza A component of flu vaccines, there are many reasons why people in this age group should be vaccinated each year.

  • Fireman B, Lee J, Lewis N et al. Influenza vaccination and mortality: differentiating vaccine effects from bias. Am J Epidemiol. 2019 Sep 170: 650-6. doi: 10.1093/aje/kwp173external iconexternal icon.
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    Myth: Researchers Rushed The Development Of The Covid

    FACT: Studies found that the two initial vaccines are both about 95% effective and reported no serious or life-threatening side effects. There are many reasons why the COVID-19 vaccines could be developed so quickly. Here are just a few:

    • The COVID-19 vaccines from Pfizer/BioNTech and Moderna were created with a method that has been in development for years, so the companies could start the vaccine development process early in the pandemic.
    • China isolated and shared genetic information about COVID-19 promptly, so scientists could start working on vaccines.
    • The vaccine developers didnt skip any testing steps, but conducted some of the steps on an overlapping schedule to gather data faster.
    • Vaccine projects had plenty of resources, as governments invested in research and/or paid for vaccines in advance.
    • Some types of COVID-19 vaccines were created using messenger RNA , which allows a faster approach than the traditional way that vaccines are made.
    • Social media helped companies find and engage study volunteers, and many were willing to help with COVID-19 vaccine research.
    • Because COVID-19 is so contagious and widespread, it did not take long to see if the vaccine worked for the study volunteers who were vaccinated.
    • Companies began making vaccines early in the process even before FDA authorization so some supplies were ready when authorization occurred.

    The Covid Vaccines Are Highly Effective

    What to make of Pfizer

    The effectiveness of the current COVID vaccines is quite high. In fact, it is much higher than some other vaccines we commonly receive. As a reminder, the annual flu vaccine has an effectiveness around 40-60 percent from year to year.

    The current vaccines cause a powerful immune response that makes them highly protective, even if there is a drop in antibody strength. Antibodies are not the only part of the vaccines that makes them work. There are also T cells and memory B cells and other types of antibodies.

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    Vaccine Review Approval And Monitoring

    Health Canada’s independent drug review and approval process is recognized around the world for its high standards and rigor. Our decisions are based only on scientific and medical evidence showing that vaccines are safe and effective. The benefits must also outweigh any risks.

    Find detailed technical information such as the product monograph and the regulatory decision summary:

    These 7 Conditions Make The Pfizer Vaccine Less Effective New Study Says

    The COVID vaccines authorized for emergency use in the U.S. have proven to be highly effective in protecting against symptomatic and severe COVID. While these vaccines are more effective than rates we usually see for something like the flu vaccine, “no vaccine prevents illness 100 percent of the time,” the Centers for Disease Control and Prevention explains. So it’s important to know if there is anything that could possibly make the vaccine less effective for you. The Pfizer vaccine is 96 percent effective against symptomatic COVID and 95 percent effective against severe COVID for the general population, according to a new large real-world COVID study by the Clalit Research Institute in collaboration with Harvard University. However, the resultswhich were recently published in New England Journal of Medicinealso indicate that seven common conditions can make the Pfizer vaccine slightly less effective . Read on to find out if you are in an affected subgroup and for more on this specific vaccine, Pfizer’s CEO Just Said How Often You’ll Need a COVID Vaccine.

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    Are Vaccines Safe And Effective

    Vaccines are very safe and very effective. Vaccines routinely recommended in the U.S. today provide high levels of protection against targeted diseases.

    The benefits of vaccines greatly outweigh their risks. The safest decision for parents is to vaccinate their children according to the recommended schedule.

    The most variability in vaccine effectiveness is with flu or influenza vaccines, where effectiveness varies by year and how well the vaccine that year matches the circulating influenza viruses. During seasons when the flu vaccine matches most circulating flu viruses, flu vaccines reduce the risk of flu illness by 50-60% in the overall population. Vaccine effectiveness can be higher or lower for subpopulations depending on their ability to fully respond to the vaccine.

    The effectiveness of other vaccines routinely used in the U.S. varies, but for most vaccines, 80-99% of vaccinated people are protected. Two doses of MMR, or Measles-Mumps-Rubella, vaccine, for example, provides about 99% protection against measles.

    Adverse reactions to vaccines are either minor or very rare. Common adverse reactions include fever, tiredness, and a sore arm. Serious adverse events are very, very rare. For example, some vaccines cause fever in children and very rarely, febrile seizures. Febrile seizures can be scary for parents but have not been shown to cause long-term disabilities or problems.

    What Are The Benefits Of Flu Vaccination

    Which Coronavirus Vaccine Is More Effective? Comparison Of Vaccines That Are Ready For Use

    There are many reasons to get an influenza vaccine each year. Flu vaccination is the best way to protect yourself and your loved ones against flu and its potentially serious complications.

    Below is a summary of the benefits of flu vaccination and selected scientific studies that support these benefits.

    • Flu vaccination prevents millions of illnesses and flu-related doctors visits each year. For example, during 2019-2020 flu vaccination prevented an estimated 7.5 million influenza illnesses, 3.7 million influenza-associated medical visits, 105,000 influenza-associated hospitalizations, and 6,300 influenza-associated deaths.
    • During seasons when flu vaccine viruses are similar to circulating flu viruses, flu vaccine has been shown to reduce the risk of having to go to the doctor with flu by 40 percent to 60 percent.
    • Flu vaccination has been shown in several studies to reduce severity of illness in people who get vaccinated but still get sick.
    • A 2021 studyexternal icon showed that among adults, flu vaccination was associated with a 26% lower risk of ICU admission and a 31% lower risk of death from flu compared to those who were unvaccinated.
    • A 2018 study showed that from 2012 to 2015, flu vaccination among adults reduced the risk of being admitted to an intensive care unit with flu by 82 percent.

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    Vaccine Safety After Authorization

    As for all medicines, Health Canada continues to monitor the safety of the Pfizer-BioNTech COVID-19 vaccine in Canada closely. Along with the Public Health Agency of Canada and working in close collaboration with the provinces and territories and the manufacturer, we monitor for any adverse events that may develop after immunization.

    In addition, the manufacturer is legally required to submit reports of adverse events to Health Canada.

    The manufacturer is planning to follow clinical trial participants for at least 2 years after the second dose of the vaccine is given. It must communicate any safety concerns to Health Canada.

    To ensure that the benefits of the vaccine continue to outweigh the risks, we may also impose terms and conditions at any time. For example, we can require the manufacturer to take further risk mitigation measures. We can also ask the manufacturer to submit additional safety information.

    Health Canada continues to review all the available safety data as it becomes available. We will take appropriate action, if required, to protect the health and safety of Canadians.

    Australias National Immunisation Program

    The National Immunisation Program sets out recommended immunisations for infants, children, older people and other people at risk, such as Aboriginal and Torres Strait Islander people. Most recommended vaccines are available at no cost to these groups. If you need further information, talk to your GP or immunisation provider.

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    What About Safety Of The Covid

    The FDA and other reviewers closely consider diverse populations included in the trials for safety purposes. The clinical trials for the first two COVID-19 vaccines included underrepresented minorities, older age groups, and people with conditions such as obesity, diabetes and heart and respiratory conditions.

    When Were Vaccines Developed

    These 7 Conditions Make the Pfizer Vaccine Less Effective ...

    Vaccines are not new immunisation techniques were pioneered over 200 years ago, when smallpox was a feared and deadly disease. An eighteenth-century doctor named Edward Jenner noted that workers on farms who contracted the mild cowpox disease were immune to smallpox. Jenner guessed that the germ responsible for cowpox was similar enough to the smallpox germ to train the immune system to defeat both diseases. He was correct. Immunisation in Australia today relies on similar principles.

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