Infants Exposed to HIV Have Greater Risk of RSV-Related Hospitalizations

HIV exposure significantly increased the risk of hospitalization for respiratory syncytial virus (RSV) infections among infants younger than 5 months, according to a recent study in South Africa.

RSV causes millions of hospitalizations and tens of thousands of deaths among children, with high rates of illness among infants in sub-Sahara Africa, according to the study, which was led by Meredith L. McMorrow, MD, MPH, FAAP, influenza program director for the US Centers for Disease Control and Prevention-South Africa and published in the journal Clinical Infectious Diseases.

More than 5000 infants at 3 South African hospitals were screened for severe respiratory illness between 2011 and 2016, including suspected sepsis and lower respiratory tract illness as diagnosed by a physician. Of those, 2363 were enrolled and 680 tested positive for RSV. Of those that tested positive for RSV, 21 were HIV-infected and 243 were exposed to HIV but uninfected.

The risk was greatest among the youngest infants, with more than 60% of hospitalizations associated with RSV illnesses in South African infants happening before 5 months. After the 5^th month, infants showed no statistically significant association between RSV-related hospitalizations and HIV exposure.

“In South Africa, the burden of RSV-associated hospitalization is highest in the youngest infants, suggesting maternal antenatal vaccination or birth dose monoclonal antibody might be effective strategies for reducing severe disease in infants,” the study said.

Although transmission of HIV in utero has dropped below 1% in South Africa, HIV remains prevalent, affecting more than 30% of pregnant women, the study noted.

Palivizumab is the only licensed product for RSV prevention in high-income countries. At least 4 other products are in clinical trials. Maryland-based Novavax Inc. recently completed a phase 3 trial for an RSV vaccine for women in the third trimester of pregnancy. The research was conducted across 11 countries and found that the vaccine could reduce lower respiratory tract infection in infants. It could become the first US Food and Drug Administration-approved RSV vaccine indicated for infants.

The link between HIV exposure and RSV-related illnesses has been established in prior studies. A previous trial conducted from 2009-2013 in South Africa examined the association between HIV and the length and severity of RSV-associated illness in adults. That study found that an overwhelming majority (80%) of adults with RSV were also found to have HIV. The trend was more prevalent among younger adults. The findings suggested that the RSV vaccine should be administered among people with HIV to reduce related hospitalizations.