Since the “silent transmission” of the coronavirus possibly accounts for half of all cases of COVID-19, further testing is needed, Dr. Ron Elfenbein on CBSN said Monday. The estimate that people without symptoms can spread 50% of cases is based on a model published by the National Academy of Sciences.
“If it’s really true that 50% of the spread of this comes from asymptomatic or presymptomatic people, then the only answer to that is to test everyone and expand our testing capabilities as much as possible,” said Elfenbein, a physician at emergency care in Maryland, he said.
Asymptomatic means that you are infected but never get sick, while presymptomatic means that you will develop symptoms but have not yet shown them, Elfenbein explained. In both cases, you can unknowingly transmit the virus to others.
“Silent transmission alone can withstand outbreaks even if all symptomatic cases are immediately isolated,” the study authors wrote. “Our findings highlight the urgent need to expand testing of suspected symptom-free cases, as noted in the revised guidelines by the Centers for Disease Control and Prevention.”
Antibodies and immunity.
Another study by scientists at King’s College London shows that antibody levels in people who were diagnosed with COVID-19 dropped significantly after a few months. The study only looked at 90 patients, but Elfenbein said “its conclusions seem very valid.”
While 60% of people in the study had “potent” antibodies when fighting COVID-19, only 17% had the same level of potency three months later, the researchers found.
“This type of perforation” in the prospects for collective immunity, which is when a significant part of the population is immune to the virus, either because they have had it or have been vaccinated, said Elfenbein.
“Now you don’t know that you can’t get it a second time,” he said, adding that there is anecdotal data from people who get it twice. “So this is really bad news.”
While there is no published data yet, in cases where people test positive for the virus a second or third time, “it tends to get worse and worse each time,” Elfenbein said.
“Some people argue that we are not really seeing a secondary infection, we are only seeing an initial reactivation of the virus, but the people we are talking about had multiple negative tests, so they tested positive, then they had multiple negative PCR tests, then they tested positive again, “he said.
This is also different from long distance syndrome, which is when people continue to suffer persistent symptoms for months even though they don’t test positive for the virus again, he said.
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