Thank you for taking the time to watch our fun and educational video about seniors and influenza! We have answers and more information about some of the video’s important themes below….

Question 1 – What exactly is “Herd Immunity” , ie how does my decision to not get the influenza vaccine affect others??

Vaccines not only provide individual protection for those persons who are vaccinated, they can also provide community protection by reducing the spread of disease within a population (see diagram below). The individual in red at the top of the diagram is infected with a contagious disease, and can spread it to other members of the population. If the infected case only comes into contact with vaccinated and therefore “immune” individuals the infection is contained. With a less vaccinated population there is a higher probability the infected case comes into contact with an “non-immune”person, which could lead to more cases and an outbreak. Orenstein, W. A., & Ahmed, R. (2017). Simply put: Vaccination saves lives. Proceedings of the National Academy of Sciences of the United States of America, 114(16), 4031–4033.

Ultimately it is important for all adults aged 65 and older, and their caregivers, to be vaccinated against seasonal influenza. The concept of “herd immunity” is important, where high levels of influenza vaccination will keep the burden of disease to a minimum. Since vaccination rates in Canada are at a suboptimal 40%, older adults are less likely to be protected by herd immunity, and would benefit tremendously from vaccination.

Question 2 – What is “immunosenence”, are you telling me as I age my immune system gets weaker??

Immunosenescence is a natural phenomenon of aging, characterized as a progressive weakening of the immune system over time. An aged immune system has a reduced response to vaccinations, and therefore, the geriatric population responds less effectively to current vaccination schedules. This is suggested in a 2009 study that analyzed the effectiveness of the standard-dose influenza vaccine during the 1998-2005 influenza seasons. The range of effectiveness for persons aged 15 to 64 was 62% to 76%, compared to a much lower range of 26% to 52% for those aged 65 and older (Figure 2).(1)

It becomes clear that vaccines for aging immune systems need to be designed specifically to provide a more optimal antibody response. To boost vaccine effectiveness among older adults, novel vaccination products have become available, which either utilize a higher dosage of the antigen or are combined with an adjuvant. An increased concentration of the antigen provides the immune system with a higher antigen presentation, to achieve an antigen threshold for a robust immune response. (2)

Question 3 – Can Influenza (the Flu) actually cause Heart attack and Stroke?

The influenza virus has extensive effects on inflammatory and coagulation pathways, which may lead to destabilization of vulnerable atherosclerotic plaques and thus coronary artery occlusion – the major cause of acute myocardial infarction (AMI) (Figure 3). (3-5)

Question 4 – So….. Where can I get it?

British Columbia does not have a universal influenza program, however high risk individuals such as those over 65, and their contacts (ie family members, caregivers) are eligible for the publicly funded influenza vaccine. Individuals can choose to receive their influenza vaccine at the following locations – with the Pharmacy typically being the most convenient/accessible.

Doctors Office
Temporary vaccine clinic (outreach clinics at public venues)
Community Health Centre

It is important to note the in British Columbia this year the standard dose (SD) trivalent inactivated influenza vaccine is publicly funded. There is a high-dose (HD) TIIV vaccine contains four times the antigen of a standard-dose influenza vaccine (60 ug versus 15 ug per dose). The high dose vaccine was found to be about 24.2% more efficacious than standard dose; that is, about one quarter of all influenza cases could be prevented if HD was administered instead of SD. The National Committee on Immunization (NACI), a group of experts in the fields of infectious diseases, immunology and public health, has concluded that the high-dose TIV should be offered over standard-dose TIV to persons 65 years of age and older for protection against seasonal influenza vaccine.

This season, British Columbia has chosen to fund this vaccine only for seniors living in long-term care facilities and assisted living. Those over 65 who live independently who wish to have improved protection against influenza will have to pay for this vaccine privately. The cost ranges from 75-90$ depending on the pharmacy or clinic.

Those who wish to purchase “better protection” against influenza should check out the Fluzone HD Clinic Locator – or contact us at to confirm availability of the High Dose vaccine

Question 5 – What is is an organization dedicated to improve population immunization rates through education, access, and awareness. By taking our “Best Shot” at immunizing the world, we promote adult vaccination domestically in accordance with best practice clinical guidelines, and support international immunizations abroad. Check out to learn more about us!

1. Monto AS, Ansaldi F, Aspinall R, et al. Influenza control in the 21st century: optimizing protection of older adults. Vaccine. 2009 Aug 13;27(37):5043-53.
2. Lefebvre JS, Haynes L. Vaccine strategies to enhance immune responses in the aged. Current opinion in immunology. 2013;25(4):523-8.
3. Warren-Gash C, Smeet L, Hayward AC. Influenza as a trigger for acute myocardial infarction or death from cardiovascular disease: a systematic review. Lancet Infect Dis. 2009 Oct;9(10):601-610.
4. Harskamp RE, van Ginkel MW. Acute respiratory tract infections: a potential trigger for the acute coronary syndrome. Ann Med. 2008;40(2):121-8.
5. Kwong JC, Schwartz KL, Campitelli MA et al. Acute myocardial infarction after laboratory-confirmed influenza infection. N Engl J Med 2018;378:345-53.