The National Advisory Committee on Immunization (NACI) has issued updated guidelines on the use of COVID-19 vaccines ahead of the fall and winter season. Despite current low rates of COVID-19 across Canada, NACI expects a surge in activity during the colder months, similar to patterns seen in previous years with other respiratory viruses. The guidelines aim to provide early guidance on vaccine use to help provinces and territories plan for the upcoming season, as COVID-19 could compound the impact of other respiratory viruses on the health system. NACI also anticipates the availability of an updated vaccine in fall 2024, depending on the epidemiology of SARS-CoV-2 and international recommendations.
Starting in fall 2024, NACI strongly recommends the most recent updated COVID-19 vaccines for certain high-risk groups, including all adults aged 65 and older, residents of long-term care homes, individuals with underlying medical conditions, pregnant individuals, and those from specific communities such as First Nations, Métis, and Inuit populations. Additionally, people providing essential community services are also included in the recommendation. For moderate to severely immunocompromised individuals aged five and older who are unvaccinated, NACI recommends a three-dose regimen. Previously vaccinated individuals are advised to wait six months from their last dose before receiving an updated vaccine in fall 2024.
Despite the ongoing circulation of Omicron sublineages of COVID-19 in Canada and globally, NACI notes that there is not enough data yet to determine the optimal timing to start the COVID-19 vaccination program in the fall. Previous observations suggest that COVID-19 activity typically begins to increase before fall vaccination campaigns are rolled out. In 2023, the national percent positivity of COVID-19 testing started to rise in mid-August, leading to an uptick in cases due to the presence of Omicron subvariants. Despite the spike in cases, the rollout of fall 2023 boosters did not occur until around October, highlighting the importance of timely vaccination campaigns.
NACI emphasizes the importance of staying vigilant and monitoring COVID-19 activity closely as the fall and winter months approach. Continued surveillance of COVID-19 variants, such as the JN.1 sublineages, will be crucial in informing vaccine strategies for the upcoming season. NACI recommends a minimum interval of three months from the last dose for those seeking an updated fall 2024 vaccine, ensuring that individuals who receive a spring 2024 dose will be eligible for the updated vaccine. The committee also stresses the need for ongoing research and collaboration with international advisory groups to inform vaccine recommendations.
As COVID-19 continues to pose a threat, NACI’s guidelines aim to provide timely and relevant information on vaccine use to protect vulnerable populations and mitigate the impact of the virus on the health system. The updated recommendations for fall 2024 highlight the importance of targeting high-risk groups for vaccination while ensuring equitable access to vaccines for all individuals aged six months and older. By following NACI’s guidance and staying informed of evolving COVID-19 trends, provinces and territories can effectively plan and implement vaccination campaigns to help control the spread of the virus during the upcoming fall and winter season.
