Top in ID: International travel rules, fourth dose of COVID-19 vaccine

President Joe Biden recently signed an order that loosened travel restrictions to the U.S. for vaccinated travelers.

Under the new rules, which take effect Nov. 8, all noncitizens who are not immigrants will be required to be fully vaccinated and have proof of vaccination before traveling to the U.S. A review of the travel rules was the top story in infectious disease last week.

Another top story reported that moderately and severely immunocompromised adults are now eligible for a fourth COVID-19 vaccine dose 6 months after their third dose of a messenger RNA vaccine, according to updated guidance from the CDC.

Read these and more news in infectious disease below:

Biden signs order loosening international travel rules for vaccinated passengers

President Biden ordered that restrictions on international travel to the United States be based on the vaccination status of travelers, not their country of origin. Read more.

CDC Immunocompromised adults may get fourth dose of COVID19 vaccine

Immunocompromised adults who have received a third shot of either the Pfizer-BioNTech or Moderna COVID-19 vaccine are eligible for a fourth dose 6 months later, the CDC said in updated guidance. Read more.

CDC links US cases of melioidosis to aromatherapy spray sold at Walmart

The CDC linked four cases of melioidosis in the United States — two of which were fatal — to an aromatherapy spray sold by Walmart. Read more.

COVID19 vaccination more protective than previous infection study finds

Another study has found that COVID-19 vaccination is more protective than a previous infection. Read more.

Gilead Merck begin phase 2 study of weekly two-drug HIV regimen

Gilead Sciences and Merck said they have begun a phase 2 clinical study investigating a once-weekly oral regimen of islatravir and lenacapavir for people with HIV. Read more.