This week's roundup of some of the latest scientific studies on the coronavirus and efforts to find treatments and vaccines for COVID-19 explores lasting skin problems after disease, risks associated with smoking and how new variants can evade antibody drugs.

Lifetime smoking history linked with COVID-19 death risk

Former smokers who have quit still face higher risks from COVID-19 than people who have never smoked, a new study shows. Researchers at the Cleveland Clinic Health System in Ohio and Florida studied 7,102 COVID-19 patients, including 6,020 never smokers, 910 former smokers and 172 current smokers. The risk of hospitalization and death went up with the cumulative amount patients had ever smoked and the increases in risk were similar for current smokers and former smokers, researchers found.

Those who had smoked the most – the equivalent of a pack a day for 30 years, or two packs a day for at least 15 years – had 2.25 times higher odds of hospitalization and were 89% more likely to die following a COVID-19 diagnosis when compared with never smokers, the researchers reported in JAMA Internal Medicine.

Lifetime tobacco smoking history is therefore linked with risk for hospital admission and death from COVID-19, the research team concluded, adding that illnesses typically linked with smoking, like heart and lung diseases, probably contributed to those poorer outcomes.

Skin problems can persist after COVID-19

Add bothersome skin conditions to the list of symptoms that can follow infection with the new coronavirus, a new report warns.

Between April and October, an international registry established by dermatologists received reports of roughly 1,000 COVID-19 patients with itchy welts, rashes, scaly plaques or pernio, an inflammation of the fingers and toes upon exposure to cold. In half of the cases, the skin problems lasted more than two weeks. That was more often true for patients with scaly plaques and pernio.

Given that some of the patients had only mild COVID-19, the data suggests that inflammation from the disease may persist even among those who were not seriously ill, researchers said in The Lancet Infectious Diseases.

"Since the onset of the COVID-19 pandemic, appreciation for persistent morbidity beyond the acute phase of disease has increased," they said. "To our knowledge, our data represent the largest dataset to date on persistent skin signs and symptoms of COVID-19."

One-in-three with COVID-19 may not know it

At least one-third of people infected with the highly contagious coronavirus may not realize it, a new report warns. Some of them are "presymptomatic," meaning they have no symptoms but will eventually develop them. Others will remain asymptomatic for the duration of their infection.

"Infection without symptoms ... is important because infected persons can transmit the virus to others even if they have no symptoms," the researchers said in Annals of Internal Medicine. They analyzed data from 43 studies that used gold-standard PCR testing to diagnose COVID-19 and 18 that used antibody testing to look for evidence of previous infection. These studies "provide compelling evidence that the asymptomatic fraction of SARS-CoV-2 infection is sizable," they said.

The researchers called for new strategies to control the spread of the virus, such as "inexpensive, rapid home tests to identify and contain presymptomatic or asymptomatic cases, along with government programs that provide financial assistance and, if necessary, housing to enable infected persons to isolate themselves." It will be important to know whether vaccines are preventing asymptomatic infections, they said.

Coronavirus variants escape effects of antibody drugs

Antibody therapies and vaccines for treating or preventing COVID-19 are likely to be less effective against some of the new variants of the coronavirus circulating around the world, a new study suggests. Of particular concern is the variant identified in South Africa and another one first found in Brazil with similar features.

In lab tests, Eli Lilly and Co's antibody bamlanivimab was inactive against the South Africa strain, according to a report posted on bioRxiv ahead of peer review. The drug just last week had shown an ability to cut the risk of COVID-19 by 80% for nursing home residents. The activity of one antibody in Regeneron Pharmaceuticals Inc.'s dual-antibody therapy was impaired by the South Africa variant, although the cocktail remained potent. And tests of blood from people who got either of the COVID-19 vaccines from Pfizer Inc. or Moderna Inc. showed antibodies generated by the shots were less effective against the South Africa variant, although Moderna has said it still believes its vaccine will provide protection.

"Mutationally, this virus is traveling in a direction that could ultimately lead to escape from our current therapeutic and prophylactic interventions," the researchers said. "If the rampant spread of the virus continues and more critical mutations accumulate, then we may be condemned to chasing after the evolving SARS-CoV-2 continually, as we have long done for influenza virus." Lilly and Regeneron said this week that they are working on new versions of their drugs to address the new variants.