Research on COVID-19: remdesivir and chloroquine

In December 2019, pneumonia caused by a virus emerged in Wuhan, China. The virus was subsequently identified as a new coronavirus (COVID-19), which is associated with severe acute respiratory syndrome CoV (SARS-CoV-2).

The virus’s infectious capacity, along with death rates ranging from 1% to 5%, has generated great concern around the world. Currently, there is no specific treatment against coronavirus, therefore, it is necessary to quickly identify effective treatments to combat the disease.

One of the guidelines for discovering drugs that are efficient for a recent disease is to test whether existing antiviral drugs are effective in treating related viral infections.

The efficacy of remdesivir and chloroquine against the virus was evaluated in vitro with kidney epithelial cells of an African green monkey (Vero E6) infected with COVID-19 and tests were carried out to measure the effects of the drugs on the cytotoxicity, virus performance, and infection rates of COVID-19.

In the cytotoxicity test, it was observed that the drugs presented high percentages of inhibition with respect to cytotoxicity, therefore the addition of each drug was subsequently evaluated and the stage was verified with greater efficiency.

In the addition assay, remdesivir was shown to work after virus entry, while chloroquine worked both at entry and in the stages following COVID-19 infection in Vero E6 cells. One of the advantages of chloroquine is that in addition to its antiviral activity, it has an immunomodulatory activity, which may increase its antiviral effect in vivo. These findings reveal that remdesivir and chloroquine are highly effective in controlling COVID-19 infection in vitro, but in vivo tests have to be performed to verify their effectiveness.

Wang, M., Cao, R., Zhang, L. et al. Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro. Cell Res 30, 269–271 (2020).