A lower supply of a certain type of immune cell in older people that is critical to fighting foreign invaders may help explain their vulnerability to severe Covid-19, scientists say. An antiseptic nasal spray containing povidone-iodine may help curb transmission of the new coronavirus, preliminary research suggests.

Merix Pharmaceutical Corp. announced the company’s proprietary botanical extract formula VIRACEA was found to be highly active against HSV-1 and HSV-2 in laboratory testing.

The U.S. Food and Drug Administration filed a complaint against Innovative BioDefense Inc. of Lake Forest, California, and Colette Cozean, the company’s president and chief executive officer, to prohibit them from selling Zylast topical antiseptics with claims that they are effective against infection by pathogens such as norovirus, rotavirus, flu virus, Methicillin-Resistant Staphylococcus Aureus (MRSA), and Ebola.