#18,631
Yesterday, in Canada PHAC Announces Plans To Purchase 500,000 doses Of H5N1 Vaccine, we looked at the press release on their intent to purchase a small number of doses of an H5N1 vaccine for humans.
Vaccination requires two doses - 30 days apart - so these purchases would only serve as a stop-gap measure for a relatively small number of high risk individuals (e.g. laboratory personnel conducting H5 testing, those working with infected animals, healthcare workers, etc.) depending on the size of their stockpile.Canada joins a handful of other countries - including the United States (4.8 million doses), Japan (10 million doses), the UK (5 Million doses) - in securing a small stockpile of the vaccine.
Along with yesterday's press release, the NACI (National Advisory Committee on Immunization) published a 38-page document describing how - and when - their stockpile might be used.
I've reproduced the link and the decision table below, but you'll want to follow the link to read it in its entirety. You'll find excerpts from the report's summary below that.
I'll return with a postscript after the break.
Summary of NACI statement of February 19, 2025: Rapid response on preliminary guidance on human vaccination against avian influenza in a non-pandemic context as of December 2024
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Organization: Public Health Agency of Canada
Date published: 2025-02-19
Overview
- On February 19, 2025, the Public Health Agency of Canada (PHAC) released the National Advisory Committee on Immunization's (NACI) Preliminary guidance on human vaccination against avian influenza in a non-pandemic context as of December 2024. This guidance is based on current evidence and NACI expert opinion.
- As of February 14, 2025, 68 human cases of avian influenza A(H5N1) were reported in the US since the start of 2024, primarily among dairy and poultry workers, while Canada reported one human case. Of these human cases, a small number have been severe, including the one case in Canada, and one death has been reported in North America (Louisiana, US). Most human cases can be traced to animal exposures, although some have had an unknown source of exposure.
- The number of human cases of avian influenza A(H5N1) in North America is increasing, primarily among poultry and dairy farm workers. Some Canadians may face increased risk of exposure to H5N1 viruses due to occupational hazards (e.g., poultry and dairy farm workers, laboratory workers); however, the risk to most Canadians remains low at this time.
- This NACI guidance offers a preliminary framework to advise Canadian provinces and territories (PTs) on whether to use human vaccines against avian influenza (HVAI) in a non-pandemic context, centered on the objective to prevent human infection with avian influenza A(H5N1) viruses. Preventing transmission from animals to humans will help to prevent severe disease in humans and could also help limit opportunities for viral adaptations that could facilitate human-to-human transmission.
- In the event that PTs determine it is necessary to start offering HVAI, NACI has identified key populations to consider prioritizing for vaccination including laboratory workers handling live avian influenza A (H5N1) virus and people with ongoing contact with known infected animals or their environments. NACI has also provided product-specific advice to advise PTs on recommended use of HVAI should it be needed (e.g., recommended schedule, guidance on concurrent administration).
- Refer to the full NACI statement for the detailed guidance framework.
What you need to know
- Avian influenza H5N1 outbreaks on both poultry and dairy farms have increased in recent months both globally and in North America, and cases have been reported in humans. Among the human cases of H5N1 in North America, almost all have been reported in people with exposures to dairy cattle or poultry including in non-commercial settings. While the source of exposure is not known for a few North American H5N1 cases, no evidence of human-to-human transmission has been reported to date. Almost all cases in North America have also been mild, with only a few cases of severe disease or death.
- Many countries, including Canada, are boosting surveillance activities, securing access of human vaccines against avian influenza (HVAI), and preparing for the possible use of HVAI to prevent and respond to avian influenza A(H5N1) outbreaks.
- HVAI can be used proactively in a non-pandemic context to protect people who may be at increased risk of being exposed to the virus through animals.
- At this time, based on the available supply and what is known about the epidemiological situation, NACI has provided guidance to assist provinces and territories (PTs) in deciding if, when, and how to use HVAI.
- NACI has not recommended broad deployment of HVAI, but has identified considerations for when HVAI could be used for key populations. NACI has outlined scenarios where it could be appropriate for PTs to consider using an available vaccine supply based on the evolving epidemiology.
- NACI reiterates a strong recommendation for all individuals 6 months of age and older to receive an authorized, age-appropriate seasonal influenza vaccine to reduce the burden of seasonal influenza in Canada. This includes those likely to have significant exposure to avian influenza A viruses (e.g., H5N1) through interactions with birds or mammals. While seasonal influenza vaccines do not protect against avian influenza A(H5N1), they may reduce the severity of seasonal influenza and may potentially reduce the risk of co-infection with both seasonal and avian influenza strains.
- NACI will continue to monitor the evolving evidence and epidemiology of avian influenza A(H5N1) in animals and humans, scientific developments, and evidence on HVAI, and will update guidance as necessary.
- To receive information regarding updates to the CIG and new NACI recommendations, statements and literature reviews, please subscribe to our publications mailing list.
While a vaccine will be an important tool in any pandemic response, there are no guarantees how effective any H5 vaccine will be, and it will likely be 6 - 12 months into a pandemic before large quantities of any vaccine would be available to the public.
Until then, NPIs (non-pharmaceutical interventions) - face masks, handwashing, social distancing, etc. - will be our primary tools against any novel respiratory virus.
And of course, there are no guarantees that HPAI H5 will spark the next pandemic. It is simply the one that is banging on our door the loudest right now.
