About the Study
This study is investigating the ability of a vaccine originally designed for smallpox to have a similar protective effect against mpox in people living with HIV. Blood samples will be collected at a single time point, roughly 2 years following the vaccination, to compare immune responses in people with HIV infection versus those without it. The aim is to better understand whether the vaccine is able to create a protective immune response against mpox in people with HIV. Findings from this study will also inform the design of future vaccines and vaccine strategies for people with HIV, such as the need for booster doses.
Background
Mpox is disease caused by a DNA virus in the same family as smallpox. In the past, it was found primarily in Central and West Africa. However, since May 2022, more mpox cases have been reported across the world, including in Canada and North America.
To protect people from infection, people with high risk of exposure or for severe disease were able to receive a vaccine. This vaccine was originally developed for smallpox prevention but also offers protection against mpox. It was used during the 2022 mpox outbreak because it was already available. Additionally, people over the age of 55, or those born in countries outside of Canada, may have also received this smallpox vaccine when they were young.
People living with HIV may be more susceptible to other viral and bacterial infections, and may not mount as strong an immune response, or as long-lasting an immune response, as people without HIV. Of the people infected with mpox in 2022, a high percentage of them were people living with HIV. These people were also ill for longer and experienced more intense symptoms than people who did not have HIV. Additionally, new mpox outbreaks have been reported in other areas of the world since 2022. Although these outbreaks involve different forms of the mpox virus (referred to as “clades”), vaccination against one clade is thought to provide some protection against future clades. For these reasons, it is important to investigate the long-term impact of the mpox vaccination on the immune response in people living with HIV.
Study Approach
A total of 80 people from Clinique Medical L’Actuel in Montreal will be invited to participate in this study. Blood will be collected from both people with and without HIV, from November 2025 to February 2026. This is approximately two years following the mpox vaccine campaigns in Montreal. Among this combination of factors, there will be four distinct groups of participants, for a total of 80 participants:
- People who have not received the mpox vaccine: HIV+ (20 people) and HIV- (20 people)
- People who have received the mpox vaccine: HIV+ (20 people) and HIV- (20 people)
Within either group, some people may have received the smallpox vaccine in the past, usually in childhood. Previous receipt of the smallpox vaccine will be recorded as this may impact findings and will help in interpretation of results.
The researchers will compare differences in the number of CD4+ cells between the groups. Because CD4+ cells trigger the rest of the immune cells to act, fewer CD4+ cells make it harder for the body to respond to an infection. The researchers will also look at the levels of antibodies and the numbers of B cells, which are the cells involved in antibody production. Using this information, researchers will be able to better understand how vaccination against mpox impacts the immune system and whether this immune response persists two years following vaccination. Ultimately, this will lead to improved vaccine design for infections like mpox and will inform vaccination guidelines, such as the possible need for booster doses.
Eligibility Requirements
Not Allowed
- Unable to provide consent
- Previous mpox infection
Investigators
Here’s who is leading this study.
Can’t find what you’re looking for?
Email info@ctnplus.ca.
Related Publications
Participating Sites
Clinique Medical L’Actuel
- Montreal, Quebec
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
- Site Investigator
-
12345 Street Name,
City Name, BC V3M 9J3
- Contact Person
- contact@email.com
- 1 (604) 555-9999
Related Studies
-
CTNPT 054: Falls in older persons with HIV
Falls in older persons with HIV: Frequency, risk factors and feasibility of a future interventional trial
-
CTNPT 052: Glycoprotein 120 as a pan-toxin
Exploring the role of the soluble glycoprotein 120 as a pan-toxin driving immune dysfunction and accelerated aging in people living with HIV