Higher Risk of Severe Breakthrough COVID for Certain HIV Patients

People with HIV and moderate or severe immune suppression contended with a higher risk for severe COVID-19 after breakthrough infections, researchers reported.

When compared to people without HIV, the risk of severe breakthrough illness on multivariable analysis was 59% higher in HIV patients with CD4 counts below 350 cells/μL (adjusted hazard ratio [aHR] 1.59, 95% CI 0.99-2.46, P=0.049), according to Keri Althoff, PhD, MPH, of the Johns Hopkins Bloomberg School of Public Health in Baltimore, and colleagues.

As a result, people with HIV and moderate or severe immune suppression "should be included in groups prioritized for additional vaccine doses and risk-reduction strategies," they advised in JAMA Network Open.

In general, the risk of severe illness within 28 days of a breakthrough infection for people with HIV (regardless of CD4 count) was similar to individuals without HIV (6.7% vs 7.3%, respectively), and a booster dose of COVID vaccine was associated with a lower risk for both groups.

The CDC currently recommends an additional or second booster shot for patients with advanced or untreated HIV infection, the researchers noted, but not for those with CD4 counts above 200 cells/μL with moderate immune suppression.

Yet those with moderate immune suppression "may benefit from being included in the CDC's recommendations for those with advanced and untreated HIV," Althoff and coauthors argued.

For the Corona-Infectious-Virus Epidemiology Team (CIVET II) cohort study, the researchers examined data on 3,649 vaccinated adults who had a SARS-CoV-2 breakthrough infection up through Dec. 31, 2021. Patients were identified through the electronic health records at four academic centers and integrated health systems in the U.S. This included 1,241 people receiving treatment for HIV and 2,408 individuals without HIV. The two groups were matched by demographics and date of full vaccination status, and analyses adjusted for vaccine type, demographics, and clinical factors.

The vast majority (89%) were men, 60% were 55 or older, and 47% were Black. Three-quarters of breakthrough infections were lab-confirmed, with 49% occurring during the Delta wave and 41% occurring during Omicron.

Regardless of HIV status, severe breakthrough cases were higher in people whose primary series was the Johnson & Johnson vaccine (9.3%), followed by Pfizer (7.2%) and Moderna's (6.2%). In total, 15% received a booster dose at least 28 days after their primary series, with a higher proportion among people with HIV (19.5% vs 12.6%).

Among the group with HIV, 26% had a history of AIDS, and nearly all were virally suppressed (91%). At the time of primary series vaccination, their average CD4 count was 620 cells/μL.

A lower proportion of people with HIV had hypertension (51% vs 60%), obesity (36% vs 54%), and diabetes (25% vs 34%) compared to individuals without HIV.

In both groups, multivariable analysis showed that having a pre-vaccination SARS-CoV-2 infection was tied to a lower risk of severe breakthrough illness.

In the group with HIV, increased risk of a severe breakthrough case was seen in those with a history of cancer (aHR 1.97, 95% CI 1.05-3.51), women (aHR 2.88, 95% CI 1.03-7.11), and people with very low CD4 counts (under 200 cells/μL) at the time of being fully vaccinated (aHR 2.57, 95% CI 1.15-5.29).

Overall, hospitalizations occurred in 249 people, and 9.6% required mechanical ventilation and 20 died, with no differences based on HIV status. Overall, 33 people with breakthrough infections died within 30 days of a COVID diagnosis, 1% of people with HIV and 0.8% of those without HIV.

Study limitations included that the study included mostly male patients with access to healthcare. Also, data based on discharge coding may be affected by reimbursement practices or other factors.

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