Readers ask about antibody tests, chimeras and public health and privacy

Cover of June 6, 2020 issue

Antibody mysteries

Antibody tests can help reveal who has been infected with the coronavirus, but the tests don’t say whether the antibodies protect against future infections, Erin Garcia de Jesus reported in “So many questions on antibody testing” (SN: 6/6/20, p. 22).

Reader Bob Reckers asked if antibodies for cold-causing coronaviruses, which are detectable by the coronavirus antibody tests, could bind to the coronavirus. “This could explain the wide variations in severity of COVID‑19 infections,” he wrote. “People who recently had a [cold] … might have some level of protection.”

Antibodies produced in reaction to some colds certainly could bind to the coronavirus that causes COVID-19, says Garcia de Jesus. But those antibodies don’t appear to last long. It’s unclear whether antibodies from a recent cold would offer protection or worsen COVID-19 symptoms, she says. For dengue viruses, antibodies sometimes can lead to severe symptoms. When people who have had dengue are infected with a d­ifferent strain, antibodies from the previous infection help the new virus invade cells, putting those people at higher risk for severe symptoms. “There’s no evidence in people either way for COVID-19, and not enough time has passed for researchers to fully study this question,” Garcia de Jesus says.

Public health and privacy

Cell phone apps that have helped South Korea and China get a grip on the corona­virus’ spread could help public health workers in the United States, Jonathan Lambert reported in “A sprint to contact tracing” (SN: 6/6/20, p. 19).

To comply with contact tracing apps, people in the United States must know that their privacy is protected, reader Cielo DeCastro noted. “It must be made explicit that identification between devices is anonymized and securely stored in encrypted form to prevent violation of privacy. The application should not gather any other information or track one’s geolocation,” he wrote. DeCastro acknowledged that phone tracking may be necessary for public health, “but the people’s right to privacy must not be overlooked.”

Lambert agrees that privacy around contact tracing apps is a major issue. The TraceTogether app mentioned in the story uses anonymized data gained through proximity tracking, whereby a phone exchanges encrypted data via Bluetooth with nearby phones. This method is considered less invasive than the geolocation tracking used by many apps on our phones (SN: 2/3/18, p. 18).

In June, U.S. legislators introduced the Exposure Notification Privacy Act. This bill would require anyone who operates a contact tracing app to collaborate with public health officials, make app use voluntary and prevent commercial use of data collected by the apps.

Chimera concerns

Scientists coaxed human stem cells into populating various organs and blood of growing mouse embryos, Laura Sanders reported in “Mouse embryos host human cells” (SN: 6/6/20, p. 7).

The story “made my skin crawl,” reader Jerome Knies wrote. “What kind of moral supervision governs such experimentation?”heasked.

 Little clarity exists, Sanders says. “Individual countries have an array of guidelines for conducting human chimera experiments, and individual research institutions often have their own approval committees,” she says. For what it’s worth, the I­nternational Society for Stem Cell Research highlights two potential concerns: chimeras with humanlike brains and chimeras that can pass human genes to offspring. “The organization flagged those scenarios as ones that require careful ethical considerations,” Sanders says.


Quantum computing’s error problem” (SN: 6/20/20, p. 18) explained how two photons within a superconducting microwave cavity might represent a value of 0, with four qubits representing 1. This is incorrect. Four p­hotons would represent 1.