Jet Injector Influenza Vaccine
The inactivated influenza shot contains killed virus. Influenza shots are approved for use in people 6 months and older, including healthy people and people with chronic medical conditions. There are different types of the influenza shots available, including a high-dose vaccine for people 65 years of age and older. The high-dose vaccine is not recommended for people who have had a severe reaction to the influenza vaccine in the past.
The Best Flu Vaccine If Youre Scared Of Needles
While most people use the terms flu vaccine and flu shot interchangeably, not all flu vaccines use a needle to deliver the ingredients.
FluMist Quadrivalent is a nasal spray vaccine. However, its not the right choice for some people. This vaccine is only FDA-approved for people between ages 2 and 49. FluMist Quadrivalent is also a live attenuated vaccine, meaning it contains weakened versions of the flu viruses instead of inactivated viruses. People who are pregnant and those with certain health problems such as a weakened immune system shouldnt receive it.
When Should People Get The Flu Vaccine
Flu season runs from October to May. It’s best to get a flu vaccine as early in the season as possible, ideally by the end of October. This gives the body a chance to make antibodies that protect from the flu. But getting a flu vaccine later in the season is better than not getting it at all. Getting a missed flu vaccine late in the season is especially important for people who travel. That’s because the flu can be active around the globe from April to September.
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When To Get The Flu Shot
Flu season typically runs from late fall to early spring.
Flu shots are now available for all Ontarians. You should get a flu shot as soon as possible because it takes two weeks to take effect.
The National Advisory Committee on Immunization now recommends that COVID-19 vaccines may be given at the same time as the flu vaccine.
Talk to your doctor or pharmacy to learn more.
What Are The Types Of Flu Vaccines

Two types of flu vaccine are available for the 20202021 flu season. Both protect against the four types of influenza virus that are causing disease this season::
- the flu shot, which is injected with a needle
- the nasal spray, a mist which gets sprayed into the nostrils
In the past, the nasal spray vaccine wasn’t recommended for kids because it didn’t seem to work well enough. The newer version appears to work as well as the shot. So either vaccine can be given this year, depending on the child’s age and general health.
The nasal spray is only for healthy people ages 249. People with weak immune systems or some health conditions and pregnant women should not get the nasal spray vaccine.
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Should You Get Vaccinated At A Pharmacy
These technologies can make you a lot more nimble at responding to a flu outbreak that you didnt expect or a sudden change in whats circulating, says Conway. Some of these newer technologies were developed so that if this does happen weve at least got the capacity to be able to do that.
The hope is that these newer vaccines will prove to be more effective than the traditional immunization. An investigation published in December 2018 in the Journal of Infectious Disease found the cell-based immunization to be slightly better than the standard vaccine, and an August 2020 study in npj Vaccines showed that recombinant technology produced a stronger immune response than the egg-based vaccine. But to determine if these newer vaccines are more more protective than egg-based vaccines, more research is needed.
A paper published in February 2020 in the Journal of Biomedical Science underscored that the comparatively high cost of these alternatives to egg-based influenza vaccines have prevented them from taking a bigger share of the influenza vaccine market.
Flu Vaccine Effectiveness Over Time
The flu vaccine needs two weeks to become fully effective, and protection is thought to last for at least six months. But a person’s antibody levels in response to the vaccine can decrease over time, and different flu strains may be circulating.
Because of that and because each year the vaccine is tailored to the most concerning flu variants, people should get a flu vaccine annually.
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How To Prevent The Flu
You can take the following steps to protect yourself and your loved ones from flu:
- Get a flu vaccine
- Cover your nose and mouth with a tissue or your elbow when you cough or sneeze
- Avoid touching your eyes, nose, or mouth
- Wash your hands often with soap and water or alcohol-based hand rub
- Try to avoid close contact with sick people
- If you are sick, stay home from work or school
- If you are sick, monitor your symptoms and contact your medical provider if your symptoms are getting worse
- If you are seriously ill and at risk for complications from the flu, contact your medical provider because you may need additional treatment or hospital care
What Are The Different Types Of Flu
There are three types of flu viruses: A, B, and C. Type A and B cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, coughing, and running high fevers. Type C also causes flu however, type C flu symptoms are much less severe.
The flu is linked to between 3,000 and 49,000 deaths and 200,000 hospitalizations each year in the United States. The seasonal flu vaccine was created to try to avert these epidemics.
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Myth #: It Contains Thimerosal Which May Be Harmful
Thimerosal a preservative that contains mercury has never been shown to be harmful, Cunningham said. The type of mercury linked with nervous system damage is methyl mercury, he said. Concerns over levels of methyl have led to recommendations that pregnant women avoid eating large amounts of certain types of fish, such as swordfish.
In contrast, thimerosal is an ethyl mercury compound.
Still, because the preservative raised controversy, especially over a now-disproven link to autism, it was taken out of almost all U.S. vaccines starting in 2001, Cunningham said.
The injectable form of the flu vaccine is available to health care providers as large, multidose bottles and small vials carrying individual doses. A tiny amount of thimerosal is added to the multidose bottles to ensure that no bacteria will grow in the vaccine, Cunningham said. The individual-dose bottles contain no thimerosal.
The nasal spray form of the flu vaccine also contains no thimerosal, he noted.
Why Do Some People Not Feel Well After Getting A Flu Shot
Flu vaccine side effects are generally mild and go away on their own within a few days. Some side effects that may occur from a flu shot include soreness, redness, and/or swelling where the shot was given, headache , fever, nausea, muscle aches, and fatigue. The flu shot, like other injections, can occasionally cause fainting.
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I1 New Or Updated Information For 2020
NACI recently reassessed the wording for the recommendation on the vaccination of health care workers and other care providers as a group for whom influenza vaccination is particularly recommended. The existing evidence on HCW influenza vaccination and the reduction of morbidity associated with influenza in patients being cared for by a HCW in health care settings was considered in the context of ethics and acceptability. NACI continues to recommend that, in the absence of contraindications, HCWs and other care providers in facilities and community settings should be vaccinated annually against influenza, and recommends the inclusion of this group among the particularly recommended recipients of influenza vaccine. NACI considers the receipt of influenza vaccination to be an essential component of the standard of care for all HCWs and other care providers for their own protection and that of their patients. This group should consider annual influenza vaccination as part of their responsibilities to provide the highest standard of care.
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Where To Get A Flu Shot

Still, vaccine producers adjust the formula from year to year because the flu virus is always changing.
Basically, the virus is trying to change a little bit so it can continue to live, says Ann Philbrick, PharmD, an associate professor in the College of Pharmacy at the University of Minnesota in Minneapolis. Thats why we have to change the composition of the vaccine every year.
To make sure each years formulation is as on target as possible, health centers around the world receive and test thousands of influenza virus samples from patients throughout the year, notes the CDC. Based on studies of these samples, researchers create what they hope will be the most effective inoculation for the season.
Flu vaccines, however, vary from year to year and they may not be as effective some years as in others, says Dean Winslow, MD, an infectious disease specialist and professor of medicine at Stanford University Medical Center in Palo Alto, California.
In general, the CDC says the flu vaccination reduces the risk of illness by between 40 and 60 percent. With the flu season just starting, the effectiveness of this years vaccine is still uncertain. But even if you get vaccinated and still get sick, the shot is worth getting symptoms can be far less severe for those who are immunized.
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People At High Risk Of Complications From The Flu
- people with health conditions, such as:
- cancer and other immune compromising conditions
- diabetes
- kidney disease
- neurological or neurodevelopmental conditions
- children up to 18 years of age undergoing treatment for long periods with acetylsalicylic acid
Iv1 Inactivated Influenza Vaccine
IIVs contain standardized amounts of the HA protein from representative seed strains of the two human influenza A subtypes and either one or both of the two influenza B lineages . IIVs currently authorized for use in Canada are a mix of split virus and subunit vaccines, both consisting of disrupted virus particles. Split virus vaccines contain whole inactivated viruses split with detergent, ether, or both, while subunit vaccines are made of purified HA and NA. The amount of NA in the vaccines is not standardized. HA-based serum antibody produced to one influenza A subtype is anticipated to provide little or no protection against strains belonging to the other subtype. The potential for trivalent vaccine to stimulate antibody protection across B lineages requires further evaluation and may be dependent upon factors such as age and prior antigenic experience with the two B lineagesFootnote 79,Footnote 80,Footnote 81,Footnote 82,Footnote 83,Footnote 84.
Because of potential changes in the circulating influenza virus from year to year and waning immunity in vaccine recipients, annual influenza vaccination is recommended. Although NACI is aware of some recent studies that suggest that vaccine induced protection may be greater in individuals who have no recent vaccine history, optimal protection against influenza, season after season, is best achieved through annual influenza vaccinationFootnote 85,Footnote 86. NACI will continue to monitor this issue.
Efficacy and effectiveness
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Northern Hemisphere Influenza Season
The composition of trivalent virus vaccines for use in the 2017â2018 Northern Hemisphere influenza season recommended by the Advisory Committee on Immunization Practices on August 25, 2017, was:
- an A/Michigan/45/2015 pdm09âlike virus
- an A/Hong Kong/4801/2014 -like virus
- a B/Brisbane/60/2008âlike virus
In addition to these components, quadrivalent vaccines will also include a B/Phuket/3073/2013âlike virus .
In California, some emergency systems were strained by a spike in H3N2 flu cases. In addition, some areas experienced local shortages of oseltamivir. The severity of the flu season seemed somewhat comparable to the 2009â10 swine flu outbreak. A February 2018 CDC interim report estimated the vaccine effectiveness to be 25% against H3N2, 67% against H1N1, and 42% against influenza B.
Who Should Have The Vaccine
In 2021/22 flu season, the following people are eligible to receive the flu vaccine for free:
- All children aged 2 to 15 on 31st Aug 2021
- Those aged 50 years or over
- Those in long-term residential care homes
- Carers
- Frontline health and social care workers
- Close contacts of immunocompromised individuals
- Those aged 6 months to 65 years in at-risk groups including people with the following health conditions:
- Respiratory diseases, including asthma
- Heart disease, kidney disease or liver disease
- Neurological conditions including learning disability
- Diabetes
- A severely weakened immune system , a missing spleen, sickle cell anaemia or coeliac disease
- Being seriously overweight
Babies under 6 months old are too young to receive a flu vaccine. This is because they have maternal antibodies passed on from their mother which prevent the vaccine from working so well. Flu vaccination is offered to all pregnant women in the UK . As well as protecting pregnant women themselves, this also helps to protect their newborn babies from flu.
Your doctor may recommend the flu vaccine in other circumstances as well.
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Variability Of Influenza Virus
The influenza A and B virus genome is composed of eight negative-sense RNA segments. The virus particle consists of a host-derived lipid envelope embedded with 3 or 4 glycoproteins surrounding the ribonucleoprotein complex and the polymerase proteins . The major influenza virus surface glycoproteins are hemagglutinin , neuraminidase , and, in smaller proportions, matrix protein 2 . Influenza B virus has an additional NB protein. Matrix protein 1 and nucleoprotein are associated with viral RNA and are important for viral assembly as well as budding, while the polymerase proteins are important for viral genome replication . HA and NA are the major antigenic proteins and are used to further classify influenza A viruses into multiple subtypes. Sixteen HA and 9 NA influenza A virus subtypes that are antigenically distinct have been identified, with the possible addition of a new subtype, H17, identified recently . Currently, lineages of H1 and H3 viruses circulate endemically in humans. Only a single subtype of influenza B virus has been identified, although two distinct antigenic lineages have evolved over time and cocirculate at variable levels in humans.
V Choice Of Seasonal Influenza Vaccine: Additional Information
With the recent availability of a number of new influenza vaccines, some of which are designed to enhance immunogenicity in specific age groups, the choice of product is now more complex. Section II.5 summarizes NACI’s recommendations on the choice of currently authorized influenza vaccines. This section provides more details for these recommendations.
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What Protection Does A Flu Vaccine Provide If I Do Get Sick With Flu
Some people who get vaccinated may still get sick. However, flu vaccination has been shown in several studies to reduce severity of illness in people who get vaccinated but still get sick:
- A 2017 study showed that flu vaccination reduced deaths, intensive care unit admissions, ICU length of stay, and overall duration of hospitalization among hospitalized flu patients.
- Another study in 2018 showed that a vaccinated adult who was hospitalized with flu was 59% less likely to be admitted to an intensive care unit than someone who had not been vaccinated. Among adults in the ICU with flu, vaccinated patients on average spent 4 fewer days in the hospital than those who were not vaccinated.
In addition, its important to remember that flu vaccine protects against three or four different viruses and multiple viruses usually circulate during any one season. For these reasons, CDC continues to recommend flu vaccination for everyone 6 months and older even if vaccine effectiveness against one or more viruses is reduced.
Antigenic Drift And Shift

Two key processes that influenza viruses evolve through are and . Antigenic drift is when an influenza virus’s antigens change due to the gradual accumulation of mutations in the antigen’s gene. This can occur in response to exerted by the host immune response. Antigenic drift is especially common for the HA protein, in which just a few amino acid changes in the head region can constitute antigenic drift. The result is the production of novel strains that can evade pre-existing antibody-mediated immunity. Antigenic drift occurs in all influenza species but is slower in B than A and slowest in C and D. Antigenic drift is a major cause of seasonal influenza, and requires that flu vaccines be updated annually. HA is the main component of inactivated vaccines, so surveillance monitors antigenic drift of this antigen among circulating strains. Antigenic evolution of influenza viruses of humans appears to be faster than influenza viruses in swine and equines. In wild birds, within-subtype antigenic variation appears to be limited but has been observed in poultry.
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Flu Vaccine Efficacy Factors
There are a number of factors that influence how effective the flu vaccine is every year. The most important is strain matchingwhether the strains that the vaccine protects against match the most widely circulating flu strains during a given season.
In addition to the construction of the vaccine, there are more personal factors that influence vaccine effectiveness.