Tenofovir reduces risk of COVID-19 in pre-vaccine studies
Long after most people will be following this research, several studies have reported a protective impact of tenofovir (TD or TAF) on the risk of catching SARS-CoV-2 and/or on the severity of symptoms.
As a caution, including the latest study published in CID, this data is from the early COVID-19 epidemic, before vaccines became available. Results were seen both for people living with HIV taking ART and for HIV-negative people taking PrEP.
The results remain controversial though as other adjusted observational studies continue to not find any protective associations. 
- Lea AN et al. HIV status, tenofovir exposure and the risk of poor COVID-19 outcomes: Real-world analysis from 6 United States cohorts before vaccine rollout. Clinical Infectious Diseases 76(10):1727–1734. (15 May 2023).
- Julia del Amo. Question of whether tenofovir disoproxil fumarate/emtricitabine provides protection against clinical severity of coronavirus disease. 2019 Clinical Infectious Diseases, 76(10):1735–1737. (15 May 2023).
- Verburgh ML et al. No association between use of tenofovir disoproxil fumarate, etravirine, or integrase-strand transfer inhibitors and acquisition or severe outcomes of SARS-CoV-2 infection in people with HIV in the Netherlands. AIDS 37(9):p 1481-1486, July 15, 2023. | DOI: 10.1097/QAD.0000000000003577