Protective antibodies detectable in dried blood spots; Zinc, vitamin C show no benefit in random hospital trial

The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.

Protective antibodies detectable in dried blood spots

Researchers at Northwestern University have developed a laboratory test for measuring neutralizing antibodies against the coronavirus that requires only a single drop of blood, collected and dried on filter paper.

"Blood samples can be self-collected at home, and sent to the lab in the mail," said Thomas McDade, whose team described the technique in a report posted on Tuesday on medRxiv ahead of peer review.

Currently, to determine if someone has the neutralizing antibodies that protect against the virus that causes COVID-19, blood must be drawn at a clinic or doctor's office and sent for analysis.

The Northwestern test "produces results that are comparable to results from venous blood, and the protocol can be implemented in a short amount of time with widely available laboratory infrastructure," McDade said.

"This method allows for large-scale testing of neutralizing antibodies against COVID-19, which may be useful for evaluating the effectiveness of vaccines and the level of protective immunity in the general population."

The researchers have not yet used their test to look for neutralizing antibodies against emerging variants. "We can modify the test for specific variants as needed," McDade said.

Zinc, vitamin C show no benefit in randomiz hospital trial

In adults with COVID-19 who were not sick enough to be hospitalized, high doses of zinc or vitamin C, or both, failed to improve their symptoms or hasten their recovery, researchers reported on Friday in JAMA Network Open.

They randomly assigned 214 patients to 10 days of treatment with either a high dose of zinc, vitamin C, both, or neither.

Everyone also received standard supportive treatments from their healthcare providers.

There was no significant difference between the groups in the number of days required to reach a 50% reduction in symptoms like fever, cough, shortness of breath, and fatigue.

There was also no difference in the number of days until patients no longer had severe symptoms, in need for other prescribed medications, or in rates of hospitalizations and deaths.

Zinc and vitamin C (ascorbic acid) supplements "cannot be recommended" to ease the course of COVID-19 in outpatients, the researchers concluded.

"Most consumers of ascorbic acid and zinc are taking significantly lower doses of these supplements, so demonstrating that even high-dose ascorbic acid and zinc had no benefit suggests clear lack of efficacy," they said. -- Reuters