Patients With HIV, Low CD4 Cell Count May Be at Increased Risk of Developing Severe COVID-19 Breakthrough Infection

Researchers suggest that all patients with HIV should be considered for additional vaccine doses, among other measures, to reduce their risk.

A new study suggests that people with HIV may have a higher risk of contracting severe COVID-19 breakthrough infections after COVID-19 vaccination. While infections among patients with HIV were only 0.7% higher than patients without HIV, patients with HIV and with CD4 cell counts below 350 cells per microliter were found to have the most increased risk of developing severe breakthrough infection.

“Our findings suggest people with HIV who have CD4 counts less than 350 cells/mm3 should be considered moderately or severely immunocompromised by the CDC, and encouraged to take additional precautions to protect themselves from severe COVID-19,” said senior author Keri Althoff, PhD, MPH, associate professor in the Department of Epidemiology at the Bloomberg School, in a press release.

Within the first 4 weeks of contracting a breakthrough COVID-19 infection, the risk of severe illness was low among patients with HIV and patients without HIV (7.3% and 6.7%, respectively). However, the HIV patients who have CD4 counts at 350 cells/mm3 were 59% more at risk of severe infection compared to patients without HIV.

In the previous Corona-Infectious-Virus Epidemiology Team (CIVET)-2 study, Researchers analyzed breakthrough COVID-19 infection data of 3649 participants with and without HIV. Among post-vaccination breakthrough infections, most were mild cases, but 249 were classified as severe, meaning participants were hospitalized within 28 days of diagnosis.

In the current study, researchers performed an analysis of the 249 severe cases, comparing the risk of developing severe illness among HIV and non-HIV participants. Among the patients, 9.6% required the use of a mechanical ventilator; among those on the ventilator, 10.1% were HIV and 9.4% were non-HIV patients. Of those on a mechanical ventilator, 8% died within 30 days of hospital admittance, with a 0.7% lower rate of death among those with HIV.

Following COVID-19 vaccination, patients with HIV or cancer diagnoses,or patients who are females or older adults were associated with an increased risk of hospitalization. However, risk of hospitalization from severe breakthrough infection was lower among those who had already been infected with the COVID-19 virus.

Patients with HIV who have counts between 200 and 350 cells/mm3 were not included in this study, since they are not included in current CDC recommendations as being immunocompromised. However, Althoff noted that these new findings signal that the CDC should expand their recommendations for extra vaccine doses to include this population.

“Clinicians who care for people with HIV with moderately low CD4 counts, that is with CD4 counts less than 350 cells/mm3, should encourage them to take additional precautions to prevent severe breakthrough COVID-19 illness,” Althoff said in the press release.


Johns Hopkins University Bloomberg School of Public Health. Risk of severe breakthrough COVID-19 infection is higher for people with HIV with moderately low CD4 cell counts. EurekAlert. October 13, 2022. Accessed on October 14, 2022.