Antibody response durability following three-dose COVID-19 vaccination in people with HIV receiving suppressive ART

This research article represents the third one in a series that explores how well the COVID-19 vaccine works in people living with HIV who are receiving suppressive antiretroviral therapy (ART). This is important to study because people living with HIV can have weakened immune systems, which can dampen their ability to respond to vaccination.

This study aims to understand how long the antibody response lasts in people living with HIV who have received three doses of COVID-19 vaccine, compared to a control group of individuals without HIV. The researchers also looked at antibody responses in individuals who experienced their first SARS-CoV-2 infection after having received three vaccine doses.

The study’s main findings were as follows:

• In people living with HIV receiving suppressive antiretroviral therapy, a third dose of COVID-19 vaccine boosted antibody levels above those elicited by two vaccine doses, and were comparable to responses seen in control participants without HIV.
• However, the vaccine’s ability to stimulate antibody responses against the Omicron strains of SARS-CoV-2 were weaker than responses to the original “wild-type” viral strain. This was true for both people with HIV and those without. Notably, vaccine responses to the more recently-circulating Omicron-BA.5 strain were even weaker than earlier Omicron strains.
• After the third vaccine dose, both antibody levels and antibody function declined over time in all participants who remained COVID-19 naive (meaning, those who had never experienced a SARS-CoV-2 infection). The rate of decline was quite dramatic, though comparable between people living with HIV and controls. To illustrate how dramatic the decline was: by six months after the third dose, antibody levels in more than 80% of study participants were not high enough to be able to neutralize the Omicron BA.1 viral strain in vitro.
• By contrast, participants who experienced their first SARS-CoV-2 infection after their third vaccine dose experienced a substantial “boost” to their antibody levels and function. This was true for both people with HIV and controls. Even in individuals who had received three vaccine doses plus experienced COVID-19, antibody responses against the Omicron strains remained weaker than against the original “wild-type” variant.

The research from this paper provided evidence supporting the public health recommendation that all individuals who have not yet experienced a SARS-CoV-2 infection, regardless of HIV status, would benefit from a fourth COVID-19 dose within six months of their third dose.