Researchers in India have conducted a study showing that the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – the agent that causes coronavirus disease 2019 (COVID-19) – was lower among people living with HIV and AIDS than among the general population.

The team – from the All India Institute of Medical Sciences (AIIMS) in New Delhi – says that studies conducted by the Ministry of Health and Family Welfare in Delhi during June to July, August, and October reported that the SARS-CoV-2 seroprevalence among the Delhi population was 23.5%, 28.3% and 25.9%, respectively.

Now, Naveet Wig and colleagues have shown that among 164 people living with HIV and AIDS (PLHA) in Delhi National Capital Region, the SARS-CoV-2 seroprevalence was 14%.

"This was the first study to look at the seroprevalence of SARS-CoV-2 in an HIV population in India," say the researchers. "When compared to the general population, the present study showed a lower seroprevalence in the PLHA group."

Wig and colleagues say that the mechanisms underlying this lower seroprevalence among PLHA are unclear and that further studies are needed.

They also warn that PLHA should not be considered at a lower risk of infection or severe disease and should continue to adhere to social distancing practices and other measures designed to protect against SARS-CoV-2 infection.

A preprint version of the research paper is available on the medRxiv* server, while the article undergoes peer review.

Study: Seroprevalence of COVID-19 in HIV Population. Image Credit: NIAID

Concerns about SARS-CoV-2 infection among PHLA

Since the COVID-19 outbreak began in Wuhan, China, in late December 2019, concerns have arisen regarding whether PLHA are at an increased risk for SARS-CoV-2 infection, severe disease and death, compared with the general population.

"Yet, to date, no study has been able to show this association," writes Wig and colleagues. "On the contrary, recent studies have shown that this group has a lower incidence of COVID-19."

The team says this could be attributed to the broad-spectrum antiviral activity of anti-retroviral drugs.

However, more than a year since SARS-CoV-2 was first identified, the precise burden of COVID-19 among PLHA remains unknown, say the researchers.

Since patients with COVID-19 are often asymptomatic and developing countries still have difficulty acquiring the desired number of polymerase chain reaction (PCR) diagnostic tests, surveillance of active cases in India is challenging.

"This is further compounded by the low sensitivity of the tests," says the team. "In such situations, serological tests can often help us to estimate the disease's overall prevalence in a specified population."

What did the researchers do?

The researchers conducted an observational prospective study of 164 PLHA (aged a mean of 41.2 years) recruited from the anti-retroviral therapy (ART) center at AIIMS between September1^st and November 30^th 2020.  

Three (1.8%) of the patients were treatment naïve, 156 (95.1%) were on first-line ART and five (3.1%) were on second-line ART.

The team used a chemiluminescent immunoassay called the Abbott Architect i4000SR to test serum samples for immunoglobulin (IgG) antibodies targeting the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein.

The spike RBD mediates the initial stage of the infection process and is the main target of neutralizing antibodies following vaccination or natural infection.

Wig and colleagues say the Abbott Architect assay has been shown to be highly specific and sensitive in the detection of anti-SARS-CoV-2 antibodies.

What did the study find?

Twenty-three (14%) of the participants were seropositive for SARS-CoV-2, 16.3% of whom were male and 8.3% were female.

"When compared to the general population, the present study showed a lower seroprevalence in the PLHA group. However, the exact reasons for this lower seroprevalence are still not clear," write the researchers. "A robust study is required to look into this."

Potential factors underlying the lower seroprevalence in PHLA

Wig and colleagues suggest that the lower SARS-COV-2 seropositivity may be attributed to PHLA mainly staying indoors and avoiding social contact.

Alternatively, based on the impaired immune responses that are known to occur in this group, the participants may not have generated antibodies responses or sustained them following infection, they add.

In the early days of the pandemic, some researchers proposed that ART might be a useful early treatment for COVID-19, but subsequent studies demonstrated no such effect, say the researchers.

"However, the role of other anti-retroviral drugs or their combination is unknown and unexplored," they write.

The team also reports that most seropositive patients experienced minimal or no symptoms.

"This suggests that, like the general population, asymptomatic infections are prevalent among PLHA," says Wig and colleagues.

However, the researchers warn that PLHA should not be considered at a lower risk for acquiring infection or developing severe disease: "They should continue to practice physical distancing norms and use appropriate face masks."

*Important Notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Written by

Sally Robertson

Sally first developed an interest in medical communications when she took on the role of Journal Development Editor for BioMed Central (BMC), after having graduated with a degree in biomedical science from Greenwich University.