About The Study

CTN 328 aims to develop a cross-Canada cohort of people living with HIV who have received, or plan to receive, a COVID-19 vaccine. The study will assess how people’s immune systems respond, how long immunity might last, and the safety and tolerability of the vaccine. CTN 328 will also look at how the most vulnerable groups, such as older people or those with low CD4 counts, respond to the vaccine and whether vaccination is effective against COVID-19 variants.

About The Disease

People living with HIV are vulnerable to the development of other health concerns, including some chronic conditions and infectious diseases. At this time, it is unclear whether people living with HIV are more likely to have worse outcomes from COVID-19 than people without HIV due to the effect of HIV on their immune system or due to potential comorbidities. Because of changes to their immune systems, people living with HIV tend to have less robust immune responses to vaccines, such as the influenza, hepatitis A and B, and human papillomavirus (HPV) vaccines. Past research also suggests that when people living with HIV are vaccinated, their immune responses don’t last as long as for others. Previous COVID-19 vaccine studies were relatively short and enrolled only a small number of people living with HIV, therefore they don’t provide definitive information for this community. All of these factors combined mean that we have a lot to learn about COVID-19 vaccines in people with HIV, and how best to protect people during and after the pandemic.

Study Approach

This study aims to enroll 400 people living with HIV from four sites across Canada: Montreal, Ottawa, Toronto, and Vancouver. Depending on whether or not participants have received one or two doses of vaccine, they will provide blood samples and questionnaire responses at either three, four or five time points over the study period. Each visit will take approximately 20 minutes to one hour. Blood samples will be tested for COVID-19 antibodies before and after vaccination as well as for other markers of immune function. Researchers will analyze how these markers may change over the study period. Participants’ data will be compared to data from a group of people not living with HIV who are enrolled in a separate study. Study participants who test positive for COVID-19 infection after vaccination will provide saliva samples via Canada Post and be asked to record their signs and symptoms until they are recovered.

Learn more about the study rationale and protocol in this video (April, 2021):

Eligibility Requirements


  • Age ≥16 years
  • HIV-positive
  • Receiving at least 1 dose of COVID-19 vaccine, or have received 1 or 2 doses of a COVID-19 vaccine
  • Able to provide signed, informed consent
  • Able to attend study visits

Not Allowed

  • Signs or symptoms of active COVID-19 infection

Additional Information

If you would like to take part in this study or want more information, please refer to a participating site.

Principal Investigators

Here’s who is leading this study.

Can’t find what you’re looking for? Email ctninfo@hivnet.ubc.ca.

Dr. Aslam Anis

CTN National Director; Member, Funding Committee; Member, Steering Committee

University of British Columbia; Centre for Health Evaluation and Outcome Sciences; Arthritis Research Canada

View Bio

Participating Sites

Here’s where this study is being conducted.