Antimalarial Compounds Show Promise Against COVID-19 Variants

Strategic Insights -

Research conducted at the Instituto Conmemorativo Gorgas de Estudios de la Salud has shed light on the potential use of antimalarial compounds in treating COVID-19. The study evaluated the antiviral activity of 26 compounds against the Delta and A2.5 variants of SARS-CoV-2, isolated in Panama between 2020 and 2022. The findings indicate that some compounds, such as chloroquine and hydroxychloroquine, exhibit strong inhibitory activity against the Delta variant, while others, like amodiaquine and arteether, show activity against the A2.5 variant.

Key Takeaways:

  • Chloroquine and hydroxychloroquine were effective against the Delta variant, with chloroquine exhibiting an IC50 of 6.3 μM and a selectivity index of 8.
  • Amodiaquine and arteether showed activity against the A2.5 variant, indicating a potential benefit in treating this variant.
  • Time-of-addition experiments suggested that some compounds, such as primaquine, were ineffective during the viral adsorption phase but showed antiviral activity in the early replication phase.
  • The study highlights the critical role of selecting appropriate cell models for SARS-CoV-2 research, as drug efficacy varies between viral variants and host cell types.
  • Instituto Conmemorativo Gorgas de Estudios de la Salud researchers led the study, with Nicanor Obaldia III serving as the contact for additional information.
  • The research received financial support from the Secretaria Nacional de Ciencia, Tecnologia e Innovacion.

Statistics:

  • 26 compounds were evaluated in the study.
  • 20% antiviral inhibition threshold was used in the initial screening.
  • 80% cell viability threshold was used in the initial screening.
  • Chloroquine exhibited an IC50 of 6.3 μM.
  • Hydroxychloroquine was 1.8 times more potent against the A2.5 variant than the Delta variant.

Sources:

  • NewsRx. Data on COVID-19 Described by Researchers at Instituto Conmemorativo Gorgas de Estudios de la Salud (Antimalarial Compounds Exhibit Variant- and Cell-type-specific Activity Against Sars-cov-2 Isolated In Panama). Drug Week. July 18, 2025; p 53.
  • Frontiers in Pharmacology, 2025;16.
  • Instituto Conmemorativo Gorgas de Estudios de la Salud, Ctr Evaluac Drogas & Vacunas Antimalaricas, Dept Invest Parasitol, Panama City, Panama.