HIV and COVID-19: juxtaposition of two pandemics.

The emergence of SARS-CoV-2 in 2019 has led to a juxtaposition of two pandemics: COVID-19 and HIV/AIDS. As of March 27, 2022, the world has reported more than 480 million confirmed cases of COVID-19 and more than 6 million deaths. HIV/AIDS continues to be a major global public health pandemic: more than 37 million people were living with HIV at the end of 2020, two-thirds of whom (an estimated 25 million) are in sub-Saharan Africa. At the individual level, the COVID-19 pandemic has important implications for people living with HIV and has affected the delivery of HIV services.

In this issue of The Lancet HIV, two remarkable studies assess the effectiveness of COVID-19 vaccination in HIV-positive individuals. In one study, Lucas Netto and colleagues studied people living with HIV at the University of Sao Paulo, Brazil. They compared CoronaVac immunogenicity responses in people living with HIV with CD4 counts less than 500 cells per μL with people living with HIV with CD4 counts of 500 cells per μL or more. Immunogenicity was reduced in those with CD4 counts less than 500 cells per μL, suggesting that these individuals could be at increased risk of an inadequate antibody response to vaccines. However, these results do not corroborate other findings from recent studies that found similar immunogenicity following other types of COVID-19 vaccines (eg, ChAdOx1 and BNT162b2) in people living with HIV compared to controls. In a second study, Shabir Madhi and colleagues studied NVX-CoV2373 vaccine immunogenicity in people with HIV compared with HIV-negative individuals and stratified by baseline SARS-CoV-2 serostatus. The safety of NVX-CoV2373 in people living with HIV was similar to that in those who were HIV-negative. However, people with HIV who were not previously exposed to SARS-CoV-2 had attenuated humoral immune responses to NVX-CoV2373 compared with their HIV-negative vaccine counterparts. It is unknown if the difference in the immunological responses observed in the study by Netto and colleagues and those by others using the ChAd0x1 and BNT162b2 vaccines were due to the type of the vaccines used. At any rate, both studies clearly suggest the need for strategies to improve vaccine immunogenicity in people living with HIV. The peculiarity in people living with HIV is the compromised immune system from chronic HIV infection and the use of antiretroviral therapy, which might increase the risk of SARS-CoV-2 infection and mortality from COVID-19. People with HIV with low CD4 counts and those not on antiretroviral therapy might have the greatest risk of developing severe symptoms of COVID-19 or not controlling SARS-CoV-2.

Vaccination of people living with HIV is essential as these individuals might not clear SARS-CoV-2 virus effectively, which could lead to the emergence of new variants. In addition, unvaccinated people with HIV are four times more likely than HIV-negative people to experience symptoms of long COVID after acute COVID-19 illness. These symptoms are associated with higher levels of inflammatory markers.

Two-thirds of people living with HIV are in Africa. However, only 15% of the 1·3 billion people living on the continent have been fully vaccinated. Vaccine inequity in low-income and middle-income countries (LMICs), especially where the burden of HIV/AIDS is high, will obviously lead to limited access to vaccines for people living with HIV. Because vaccines are steadily becoming available in LMICs, coordinated efforts and partnerships are needed to scale up vaccination and delivery in these countries. This is the only way that people living with HIV will be able to access COVID-19 vaccination.

The juxtaposition of the COVID-19 and HIV pandemics also has a tremendous impact on HIV service delivery. In South Africa, for instance, because of the COVID-19 pandemic and responses to it, there was a substantial decline in the number of people living with HIV starting treatment and an estimated 47% decrease in HIV testing in April, 2020. Disruptions to HIV services could lead to worse outcomes for those with HIV and potentially increased HIV transmission. As such, addressing co-morbidities and ensuring a secure supply of antiretroviral therapy for people living with HIV during the COVID-19 pandemic is crucial. Delivery platforms for HIV services have been used to scale up COVID-19 vaccination in some African countries, such as Lesotho. Such platforms could facilitate access to vaccination for people living with HIV. Longitudinal studies are also needed to gain further insights into responses to different COVID-19 vaccines in people living with HIV.

I declare no competing interests.