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.
Ii7 Vaccine Safety And Adverse Events
Post-marketing surveillance of influenza vaccines in Canada has shown that seasonal influenza vaccines have a safe and stable profile. In addition to routine surveillance, every year during the seasonal influenza vaccination campaigns, PHAC and the Federal/Provincial/Territorial Vaccine Vigilance Working Group of the Canadian Immunization Committee conduct weekly expedited surveillance of AEFIs for current influenza vaccines in order to identify vaccine safety signals in a timely manner. Refer to the Canadian Adverse Events Following Immunization Surveillance System web page for more information on post-marketing surveillance and AEFIs in Canada.
All influenza vaccines currently authorized for use in Canada are considered safe for use in people with latex allergies. The multi-dose vial formulations of inactivated influenza vaccine that are authorized for use in Canada contain minute quantities of thimerosal, which is used as a preservativeFootnote 15,Footnote 16 to keep the product sterile. Large cohort studies of administrative health databases have found no association between childhood vaccination with thimerosal-containing vaccines and neurodevelopmental outcomes, including autistic-spectrum disordersFootnote 17. All single dose formulations of IIV and LAIV are thimerosal-free. Refer to Vaccine Safety in Part 2 of the CIG for additional information.
Common adverse events
Less common and serious or severe adverse events
Other reported adverse events and conditions
Who Is Most At Risk
Complications from the flu can include serious conditions, like pneumonia or heart attacks and, in some cases, death. Flu causes about 12,200 hospitalizations and 3,500 deaths in Canada each year.
Some people are more vulnerable to complications and hospitalization from the flu:
- babies under 6 months old are too young to get the flu shot, but they’ll get some protection if their parent got the flu shot while they were pregnant
- children under 5 years of age, because their immune systems are developing, and their airways are small and more easily blocked
- people 65 years old and older, because their immune systems are weaker and they are more likely to have an underlying condition that increases their risk
- pregnant people, because their immune system, heart and lungs change especially later in pregnancy making them more likely to get seriously ill from the flu
- people with underlying health conditions, such as asthma, heart disease or diabetes
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Are The New Vaccines Safe
Both vaccines are safe, but commonly cause mild side-effects, and very rarely can cause serious side-effects. However, these risks from the vaccine are less than from getting influenza infection.
The main side-effect of vaccines relates to their effect in stimulating the immune system.
In many people they cause a sore arm and, less commonly, a fever. The side-effects of these new flu vaccines are slightly more common than with standard vaccines.
Generally, these side-effects are mild and don’t last long.
None of the flu vaccines used in Australia contains live virus and therefore can’t cause flu infection. However, the vaccination season usually occurs around the same time as when another respiratory virus circulates, so this respiratory infection is commonly misattributed to vaccination.
Rare but serious side-effects, such as Guillain Barre Syndrome , have been described after flu vaccination.
Studies suggest the risk of these side-effects are less common after the flu vaccine than after flu infection.
People with allergies should discuss flu vaccines with their doctor. In the past, there has been concern the flu vaccines, which are manufactured in eggs, may elicit allergic reactions in people with egg allergy.
However, it is now thought people with egg allergies can receive flu vaccines safely under appropriate supervision.
In 2009, an adjuvanted vaccine was thought to be implicated in cases of narcolepsy in Europe.
Which Vaccine Is Right For You
Since 2009, a higher-dose flu vaccine called Fluzone High-Dose has been available for adults 65 and over. Like the regular-dose flu vaccine, it contains the three flu strains experts believe will be most prevalent in the upcoming flu season. But it also contains four times the usual amount of immune-stimulating antigens against the virus.
Is it worth getting the high-dose vaccine if you’re over 65? “I think it’s an area of much debate and discussion,” Dr. Choi says. While some studies have found the high-dose vaccine stimulates a higher immune system response in the lab, it’s not yet clear whether that translates into better protection against the flu in the real world.
The high-dose vaccine also comes with some downsides worth considering: more pain, redness, and swelling at the injection site, as well as bodywide side effects like muscle pain, headache, and fever. Most of these effects are mild and short-lived.
There are currently no official recommendations advising seniors to switch to the high-dose flu vaccine. Dr. Choi recommends weighing the pros and cons with your doctor to help you decide.
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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.
Recommendation on the use of LAIV in HIV-infected individuals
What Is In This Years High
Fluzone High-Dose Quadrivalent the high-dose flu vaccine is an inactivated influenza vaccine. This means it contains a certain amount of dead flu viruses . Because the viruses in the shot are dead, you cannot get sick with influenza from the vaccine.
The high-dose flu vaccine is a quadrivalent vaccine, meaning it contains four different strains of the influenza virus. The vaccines exact composition changes every year in an effort to match the strains expected to circulate during flu season .
This years high-dose flu vaccine includes the following strains:
-
Two type A influenza viruses H1N1 and H3N2
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Two type B influenza viruses Victoria and Yamagata lineages
Fluzone High-Dose Quadrivalent is an egg-based vaccine, meaning chicken eggs were used to create the vaccine. If you have an egg allergy, its best to discuss this with your healthcare provider before getting your flu vaccine.
Most people with egg allergies are still able to receive egg-based flu vaccines. But if you are advised to avoid egg-based vaccines, there are flu vaccine options available that are made without eggs .
The vaccine also includes the following inactive ingredients to help create and stabilize the shot:
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Formaldehyde an ingredient that kills the virus during vaccine production
-
Sodium chloride the liquid that the virus is placed in to allow it to be injected
The syringe the vaccine comes in is not made with rubber latex, so its safe for people with latex allergies to receive it.
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Iii1 People At High Risk Of Influenza
All pregnant women
NACI recommends the inclusion of all pregnant women, at any stage of pregnancy, among the particularly recommended recipients of IIV, due to the risk of influenza-associated morbidity in pregnant womenFootnote 25,Footnote 26,Footnote 27,Footnote 28,Footnote 29, evidence of adverse neonatal outcomes associated with maternal respiratory hospitalization or influenza during pregnancyFootnote 30,Footnote 31,Footnote 32,Footnote 33, evidence that vaccination of pregnant women protects their newborns from influenza and influenza-related hospitalizationFootnote 34,Footnote 35,Footnote 36,Footnote 37, and evidence that infants born during influenza season to vaccinated women are less likely to be premature, small for gestational age, and of low birth weight than if born to women that had not received an influenza vaccineFootnote 38,Footnote 39,Footnote 40,Footnote 41. The risk of influenza-related hospitalization increases with length of gestation .
Refer to the Statement on Seasonal Influenza Vaccine for 2011-2012 and the Statement on Seasonal Influenza Vaccine for 2012-2013 for further details on influenza vaccination during pregnancy.
Adults and children with chronic health conditions
Neurologic or neurodevelopment conditions
People of any age who are residents of nursing homes and other chronic care facilities
Adults 65 years of age and older
All children 6-59 months of age
Indigenous peoples
Ii4 Efficacy Effectiveness And Immunogenicity
Efficacy and effectiveness
Influenza vaccine has been shown in randomized controlled clinical trials to be efficacious in providing protection against influenza infection and illness. However, the effectiveness of the vaccine-that is, how it performs in settings that are more reflective of usual health care practice-can vary from season to season and by influenza vaccine strain type and subtype. Influenza vaccine effectiveness depends on how well the vaccine strains match with circulating influenza viruses, the type and subtype, as well as the health and age of the individual receiving the vaccine. Even when there is a less-than-ideal match or lower effectiveness against one strain, the possibility of lower VE should not preclude vaccination, particularly for people at high risk of influenza-related complications and hospitalization, since vaccinated individuals are still more likely to be protected compared to those who are unvaccinated.
Immunogenicity
Antibody response after vaccination depends on several factors, including the age of the recipient, prior and subsequent exposure to antigens, and the presence of immune compromising conditions. Protective levels of humoral antibodies, which correlate with protection against influenza infection, are generally achieved by 2 weeks after vaccination however, there may be some protection afforded before that time.
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Are There Benefits Of Fluzone High
Data from clinical trials comparing Fluzone to Fluzone High-Dose among people 65 years and older indicated that a stronger immune response occured after vaccination with Fluzone High-Dose. A study published in the New England Journal of Medicineexternal icon indicated that the high-dose vaccine was 24% more effective in preventing flu in adults 65 years and older relative to a standard-dose vaccine. Another study published in The Lancet Respiratory Medicineexternal icon reported that people 65 years and older who got Fluzone High-dose had a lower risk of hospital admission compared with people in that age group who got the standard-dose Fluzone, especially those living in long-term care facilities. This study was conducted during the 2013-14 flu season among more than 38,000 resident of 823 nursing homes in 38 states.
For the 2021-22 season, all Fluzone High-Dose vaccine will be quadrivalent. Data comparing the effectiveness of Fluzone High-Dose Quadrivalent with standard-dose inactivated quadrivalent vaccines are not yet available.
Iv5 Additional Vaccine Safety Considerations
Influenza vaccine is safe and well tolerated. Contraindications, precautions, and common AEs are described in Section II. Additional information regarding egg-allergic individuals and GBS is provided below.
Egg-allergic individuals
After careful review of clinical and post-licensure safety data, NACI has concluded that egg-allergic individuals may be vaccinated against influenza using any appropriate product, including LAIV, without prior influenza vaccine skin test and with the full dose, irrespective of a past severe reaction to egg and without any particular consideration, including vaccination setting. The amount of trace ovalbumin allowed in influenza vaccines that are authorized for use in Canada is associated with a low risk of AE. The observation period post-vaccination is as recommended in Vaccine Safety in Part 2 of the CIG. As with all vaccine administration, vaccine providers should be prepared with the necessary equipment, knowledge, and skills to respond to a vaccine emergency at all times.
Refer to the Statement on Seasonal Influenza Vaccine for 2018-2019 for safety data supporting this recommendation for IIV and LAIV.
Guillain-Barré syndrome
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What Is The Senior Flu Shot
The senior flu shot is a vaccine developed specifically for adults age 65 and older to protect them against the flu virus. According to the CDC, seniors need stronger protection because immune systems tend to weaken with age, putting older adults at an increased risk of serious flu-related complications, such as pneumonia, other respiratory problems, hospitalizations, and even death. The flu can also worsen chronic conditions that are common in seniors like diabetes, asthma, and chronic obstructive pulmonary disease.
The senior flu shot creates a stronger immune response that helps older adults immune systems fight the flu virus more effectively than the regular flu shot. The vaccine works by stimulating the production of antibodies that protect seniors against the virus.
While older adults may get any flu vaccine approved for their age group, two flu vaccines were developed specifically for seniors: the high-dose flu vaccine and the adjuvanted flu vaccine.
Other Methods Of Manufacture
Methods of vaccine generation that bypass the need for eggs include the construction of influenza virus-like particles . VLP resemble viruses, but there is no need for inactivation, as they do not include viral coding elements, but merely present antigens in a similar manner to a virion. Some methods of producing VLP include cultures of Spodoptera frugiperdaSf9 insect cells and plant-based vaccine production . There is evidence that some VLPs elicit antibodies that recognize a broader panel of antigenically distinct viral isolates compared to other vaccines in the hemagglutination-inhibition assay .
A gene-based DNA vaccine, used to prime the immune system after boosting with an inactivated H5N1 vaccine, underwent clinical trials in 2011.
On November 20, 2012, Novartis received FDA approval for the first cell-culture vaccine. In 2013, the recombinant influenza vaccine, Flublok, was approved for use in the United States.
On September 17, 2020, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for Supemtek, a quadrivalent influenza vaccine . The applicant for this medicinal product is Sanofi Pasteur. Supemtek was approved for medical use in the European Union in November 2020.
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The Centers For Disease Controls 2021
Annual flu vaccination is recommended for everyone six months and older. Different flu shots are approved for people of different ages. In general, if you are pregnant or have an underlying health condition, you should still get a flu shot, but you can talk to your healthcare provider first if you are concerned.
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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What Flu Shot To Take
The Advisory Committee on Immunization Practices at the CDC does not recommend one vaccine over the other.
Englund said the high-dose vaccines are preferable for patients 65 and older, but they should get the regular dose if a high-dose is unavailable.
“If the option is to get the standard dose or nothing,” Englund said. “We absolutely prefer the standard dose vaccine.”
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Fluzone High-Dose and FLUAD, like many other vaccines, are egg-based. Patients with severe egg allergies shouldn’t get the shot.
It’s not recommended for people who have a rare disorder called Guillain-Barré syndrome, in which the body’s immune system attacks the nerves.
Side effects for the high-dose vaccines mirror the standard dose: soreness around the injection site and a low, 24-hour fever.
Schaffner said this shouldnt deter patients as the alternative can be fatal.
A sore arm and one day of fever is a small price to pay to get prevention against influenza, which can be a very deadly infection, he said.
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