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  11th IAS Conference on HIV Science 18-21 July 2021
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SARS-CoV-2 Rate Similar in TDF
PrEP Users and Matched No-TDF Controls

  IAS 2021, 11th IAS Conference on HIV Science, July 18-21, 2021
Mark Mascolini
Prevalence of SARS-CoV-2, the COVID virus, in HIV-negative people using tenofovir disoproxil fumarate (TDF)-based PrEP stood at about 10% in a 2020 French analysis [1]. Because prevalence of the novel coronavirus was similar in a matched group not using TDF, researchers suggested that “TDF/FTC has no role in reducing SARS-CoV-2 acquisition.”
Controversy surrounds the utility of TDF in lowering SARS-CoV-2 risk and COVID-19 morbidity. The rationale for a TDF benefit, explained French Prevenir trial researchers who conducted this study, rests on a potential interaction between tenofovir and a mechanism crucial to SARS-CoV-2 replication. This coronavirus is a positive-sense single-strand RNA virus whose replication depends on RNA-dependent RNA polymerase (RdRp). The triphosphate form of tenofovir diphosphate inhibits RdRp activity in HIV and HBV and has antiviral activity against SARS-CoV-2 in lab studies and in ferrets [2,3]. In a 77,590-person HIV cohort, people taking TDF/FTC had a lower risk of COVID-19 and COVID-related hospital admission than people taking combinations not including TDF/FTC [4].
To help determine whether TDF has any impact on SARS-CoV-2 in people without HIV, the Prevenir team compared rates of SARS-CoV-2 immunoglobulin G (IgG) anti-Spike in men using TDF/FTC PrEP and in matched controls not taking TDF/FTC. The TDF group consisted of HIV-negative men in the Paris-region Prevenir trial of daily versus on-demand PrEP between May and October 2020. The no-TDF group was drawn from men in the Paris area of the Sapris-Sero survey to estimate SARS-CoV-2 antibody prevalence in the French general population. Researchers matched Sapris-Sero men to Prevenir men by age (+/- 5 years), socio-occupational category, and sampling date (+/- 1 month). The investigators chose these matching criteria because the Sapris-Sero study linked them to risk of SARS-CoV-2 infection.
The primary outcome of this analysis was the proportion of participants positive for SARS-CoV-2 IgG anti-Spike. Researchers considered low-positive or undetermined IgG results as negative. They compared the two study groups by odds ratios estimated by logistic regression stratified on each matched pair.
The researchers ended up with 844 TDF-exposed people in the Prevenir group and 844 TDF-naive people in the Sapris group. The Prevenir group was younger (median 38 vs 41 years, P < 0.0001). The largest Prevenir contingent (49.4%) gave samples in September-October 2020, while the largest Sapris group (61.1%) gave samples in July-August 2020. The biggest proportion of each group (59.1% Prevenir, 68.5% Sapris) had an executive job, while 24.0% and 16.7% of each group listed themselves as “employees.”
In the whole study population, SARS-CoV-2 anti-Spike IgG prevalence was similar in the TDF-exposed Prevenir group (10.3%) and the TDF-naive Sapris group (9.2%). Results were similar in a 1460-person fully matched population: 10.1% in Prevenir and 9.0% in Sapris. Odds ratios (OR) for SARS-CoV-2 positivity showed little difference when comparing the Prevenir group with the Sapris group for the whole study population (OR 1.1, 95% confidence interval 0.819 to 1.540, P = 0.4700) or the fully matched population (OR 0.8, 95% confidence interval 0.559 to 1.121, P = 0.1876).
Finally, SARS-CoV-2 positivity did not differ significantly between 424 Prevenir participants who took TDF/FTC daily (9.2%) and those who took it on-demand (only before and after sex) (11.5%) (P = 0.2762).
This matched case-control comparison of middle-aged HIV-negative people who did or did not use TDF/FTC PrEP found no evidence that TDF may help ward off SARS-CoV-2 infection.
1. Delaugerre C, Assoumou L, Maylin S, et al. SARS CoV-2 seroprevalence among HIV-negative participants using tenofovir/emtricitabine-based PrEP in 2020: a sub-study of PREVENIR-ANRS and SAPRIS-Sero. IAS 2021, 11th IAS Conference on HIV Science, July 18-21, 2021. Abstract OAC0201.
2. Rocha YM, Acácio de Moura G, Ramos de Oliveira J, Deadame de Figueiredo Nicolete L, Nicolete R. Potential repurposing of drugs with anti-SARS-CoV-2 activity in preclinical trials: a systematic review. Curr Med Chem. 2020 Oct 5. doi: 10.2174/0929867327666201005113204. Online ahead of print. https://pubmed.ncbi.nlm.nih.gov/33019921/
3. Park SJ, Yu KM, Kim YI, et al. Antiviral efficacies of FDA-approved drugs against SARS-CoV-2 infection in ferrets. mBio. 2020;11:e01114-20. doi: 10.1128/mBio.01114-20.
4. del Amo J, Polo R, Moreno S, et al. Incidence and severity of COVID-19 in HIV-positive persons receiving antiretroviral therapy: a cohort study. Ann Intern Med. 2020;173:536-541. doi: 10.7326/M20-3689.