Which drugs are being used to treat coronavirus?
A new disease is always a health challenge. What are all the symptoms that a patient can develop? What effects does it have on the sick? How is the disease transmitted? All these questions have been finding answers since the first COVID-19 case was reported in a Wuhan market, in China's Hubei province, last December.
With great similarities to SARS, the virus that in 2002 caused the death of 774 people and affected more than 8,000, the new coronavirus was treated with several antibiotics to fight the bacteria that produce pneumonia. The use of steroids and the antiviral ribavirin was initially suggested as a treatment, but experience has not provided scientific evidence that it is effective.
Research teams have now set a goal to achieve effective vaccines and treatments against the virus within a year and a half. The World Health Organization (WHO) says there is still no vaccine or antiviral to treat COVID-19. So far, some of the drugs that have been tested to mitigate the effects of the disease include the antiviral drug remdesivir, which was developed for Ebola, and chloroquine and hydroxychloroquine, both for malaria. These two have yielded beneficial and encouraging results, though not entirely conclusive.
At this point, it should be remembered that the U.S. Food and Drug Administration (FDA) has authorized the emergency use of remdesivir as an experimental drug in patients infected with the virus, as U.S. President Donald Trump announced this week.
The U.S. pharmaceutical company Gilead Sciences has manufactured the drug, which was approved to be used after a clinical study showed how remdesivir shortened recovery time in some patients. "We’re humbled by this being an important first step for patients, for hospitalized patients", Daniel O'Day, Gilead's CEO, said at a press meeting with Trump.
This study, published in The New England Journal of Medicine, announced results from a cohort analysis of 53 patients hospitalized with severe complications of COVID-19 who were treated with the investigational antiviral remdesivir. The majority of patients demonstrated clinical improvement, though it has not been possible to verify that this was due to remdesivir.
Anthony Fauci, the director of NIAID and senior scientific advisor to the U.S. president, said that this antiviral speeds up the recovery period of those infected. However, such statements are controversial, since the results presented by Fauci are based on data which are still provisional. In addition, a study conducted in the first epicenter of the pandemic, Wuhan, and published by the medical journal The Lancet, found no evidence that this antiviral was beneficial in the fight against the virus.
More drugs, but no certainty
Besides remdesivir, other therapies have been tried, such as a combination of hydroxychloroquine, used to treat malaria, and an antibiotic, both with inconsistent results. Blood plasma transfusion from people who have overcome the disease to active patients with COVID-19 has also been tried, but antibodies have not been well detected in donors who have passed the infection, so that blood cannot be used, said Ramón García Sanz, president of the Spanish Society of Hematology and Hemotherapy.
Another study, published by the New York Institute of Technology, has linked a centuries-old vaccine to COVID-19. This research, although preliminary, has studied the use of the tuberculosis vaccine as a new tool in the fight against the disease. The Bacille Calmette-Guérin vaccine (BCG), as it is scientifically known, offers broad protection against respiratory infections. This research was presented at the end of March and shows the different impact of the disease in different parts of the world. These differences are attributed to cultural norms, health infrastructures and government response. The doctors who conducted this study claim that BCG not only protects against tuberculosis or TB, but also reduces the damage caused by other diseases, although none of this research is conclusive.
By April, the WHO reviewed three clinical trials of possible treatments for BCG-19, both in countries where BCG vaccine is used and those regions where it is not. Although the WHO has stated that the number of infections is lower in countries where BCG is injected than where it is not, the organization has not taken this result as definitive since these studies are often biased by demographic differences.
The research teams are working around the clock, with more than three and a half million people infected and around 250,000 deaths. According to John Bell, professor of medicine at Oxford University, British scientists hope to have a signal about a possible vaccine by June. For now, all that remains is to wait and follow the hygiene and social distancing guidelines that have left more than half the world confined to their homes.