MERS virus shrugs off antibiotic assault 

A widely used class of antibiotics has shown potential in supressing certain viral infections but offers no significant benefit to patients with Middle East Respiratory Syndrome (MERS), say researchers at KAIMRC. 

Macrolide drugs, typically used in the treatment of acute and chronic infections, and which include erythromycin, roxithromycin, azithromycin and clarithromycin, are useful weapons in the arsenal against bacterial infections of the respiratory tract. They also offer some additional benefits. 

“There are multiple studies that shows that macrolides have immune-modulatory effects and may be beneficial in viral infection,” says Yaseen Arabi, who leads the KAIMRC team. 

Unfortunately, the data is not always clear-cut, with some studies showing that these drugs can relieve symptoms in patients infected with influenza or respiratory syncytial virus, while others do not. 

Pneumonia is a common feature of MERS, a viral respiratory illness caused by a coronavirus, and many patients with this symptom receive macrolides as a first line of treatment and well before formal diagnosis. In order to determine whether this treatment influenced the length of disease, Arabi and colleagues looked at the medical data from 349 hospitalized MERS patients at 14 hospitals across Saudi Arabia in which 136 of these patients were given macrolide antibiotics.

There were no meaningful differences in terms of clinical outcomes between the two sets of patients. The mortality rate in the 90 days following the start of treatment was slightly lower in the macrolide-treated group (60.3% versus 70.4%). But, according to the researchers, these differences are not statistically significant. 

This treatment also had no meaningful impact in terms of accelerate the clearance of the virus responsible for MERS. 

There is a possibility that this analysis may have been affected by factors outside the researchers’ control. But Arabi believes that this may simply reflect the underlying complexity of the immune response to macrolides, which in turn explains the seemingly contradictory results obtained to date with these drugs. “These are different viruses, and different study designs,” he says.

There seems to be more hope for MERS patients, however, in the ‘MIRACLE’ study, a clinical trial spearheaded by KAIMRC that Arabi and his colleagues are in the midst of recruiting subjects for. 

MIRACLE will be investigating the extent to which a combination of multiple antiviral drugs and the immunomodulatory protein interferon β-1b bolster the survival of infected patients. The trial’s coordinators aim to finish collecting their clinical data by the end of this year.

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