August 7, 2020 by John Fernandez
Roundup: COVID-19’s ‘Airborne’ Risk; Update on Antibody Immunity; and a COVID/Flu Single Test?
Scientists Urge More Focus on ‘Airborne’ Transmission of COVID-19
COVID-19 spreads mainly from person to person through respiratory droplets from an infected person who coughs, sneezes, talks, or raises their voice, states the U.S. Centers for Disease Control and Prevention (CDC). These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.
But mounting scientific evidence indicates that the coronavirus droplets or aerosols can stay in the air for a period of time, infecting people as they inhale. This possible “airborne” quality is now being considered by the World Health Organization (WHO) after the publication of a letter signed by 239 scientists that urged the agency to accept the likelihood that people can catch COVID-19 from droplets floating in the air.
The WHO now says there is “emerging evidence” of airborne transmission of the coronavirus.
Benedetta Alleganzi, M.D., WHO Technical Lead for Infection Prevention and Control, said during a briefing this week that the agency has collaborated with many of the scientists who signed the letter.
“We acknowledge that there is emerging evidence in this field, as in all other fields regarding the COVID-19 virus and pandemic,” Alleganzi stated. “And, therefore, we believe that we have to be open to this evidence and understand its implications regarding the modes of transmission, and also regarding the precautions that need to be taken.”
In their letter, the group of 239 scientists appealed for greater recognition of the potential airborne transmission of coronavirus to encourage people to better protect themselves from infection.
The scientists wrote: “We are concerned that the lack of recognition of the risk of airborne transmission of COVID-19, and the lack of clear recommendations on the control measures against the airborne virus, will have significant consequences. People may think that they are fully protected by adhering to the current recommendations. But, in fact, additional airborne interventions are needed for further reduction of infection risk.”
Study in Spain Finds Antibody Immunity Can Only Last for Weeks
Much is still unknown about COVID-19 in the medical and scientific communities, including how long antibodies survive in the body after a patient has recovered.
In a new study, the Spanish government and leading epidemiologists in Spain sought to determine what percentage of the population there had developed antibodies that could provide immunity from the coronavirus. Researchers found that just 5 percent of those tested across Spain maintained antibodies to the virus. The findings from the study of almost 70,000 people in Spain were published by the medical journal The Lancet.
The study’s authors concluded that “despite the high impact of COVID-19 in Spain, prevalence estimates (of antibodies) remain low and are clearly insufficient to provide herd immunity.” Herd immunity is achieved when enough people become immune to a virus to stop its spread. It is estimated that from 70 percent to 90 percent of a population needs to be immune to protect the uninfected and establish “herd immunity.”
The Spanish study also found that 14 percent of people who had tested positive for coronavirus antibodies in a first round of testing no longer tested positive in testing that took place a few weeks later.
The disappearance of antibodies was predominant among those who reported very mild symptoms or who had been asymptomatic, or displaying now symptoms.
“Immunity can be incomplete, it can be transitory, it can last for just a short time and then disappear,” stated Raquel Yotti, the director of Spain’s Carlos III Health Institute, which helped conduct the study.
FDA Gives Go-Ahead for CDC Test to Detect Flu and COVID-19 With Single Sample
Ahead of this year’s flu season this Fall, the U.S. Food and Drug Administration said it has given the U.S. Centers for Disease Control and Prevention (CDC) the authority to develop a new diagnostic test for healthcare providers that can detect both COVID-19 and the flu in individuals that may have been exposed to the coronavirus.
“With the authorization of these tests, the FDA is helping address concerns in anticipation of this upcoming flu season during the COVID-19 pandemic, which might be especially worrying for some Americans,” said FDA Commissioner Stephen M. Hahn, M.D., in a statement.
These “combination tests” work on a single sample from a patient for multiple respiratory diseases, such as COVID-19 and the seasonal flu, which can show similar symptoms. “With just one swab or sample, combination tests can be used to get answers to Americans faster,” added Dr. Hahn. “This efficiency can go a long way to providing timely information for those sick with an unknown respiratory ailment.”
Taking just one sample means less discomfort for the patient with faster and more comprehensive results, the FDA said. Moreover, the combination tests require fewer supplies, such as swabs and personal protective equipment, the agency said.