COVID-19 reinfection less likely to be severe; cardiac stress test useful for unexplained lingering breathlessness

By Nancy Lapid

(Reuters) – The following is a summary of some recent studies on COVID-19. They include research that warrants further study to corroborate the findings and that has yet to be certified by peer review.

Coronavirus reinfections rarely severe

Reinfections with the virus that causes COVID-19 are rarely severe, new findings suggest. Researchers in Qatar compared 1,304 individuals with a second SARS-CoV-2 infection with 6,520 people infected with the virus for the first time. The odds of developing severe disease were 88% lower for people with second infections, the researchers reported online on Wednesday in The New England Journal of Medicine. Re-infected patients were 90% less likely to be hospitalized compared to patients infected for the first time, and no one in the study with a second infection required intensive care or died from COVID-19, said Dr. Laith Jamal Abu-Raddad of Weill Cornell Medicine-Qatar in Doha. “Nearly all reinfections were mild, perhaps because of immune memory that prevented deterioration of the infection to more severe outcomes,” he said. The risk for severe illness in people who had been infected before was only about 1% of the risk associated with initial COVID-19 infections, the researchers estimated. For half of those with a second infection, the first infection had occurred more than nine months earlier. It is not clear how long immune protection against severe reinfection would last, the researchers noted. If it does last for a long time, they speculate, it might mean that as the coronavirus becomes endemic, infections could become “more benign.”

Cardiac stress test useful for lingering breathlessness

In COVID-19 survivors struggling with lingering shortness of breath for which doctors do not have an explanation, cardiac stress testing may help identify the cause of the problem, researchers say. “The current clinical guidelines do not recommend cardiopulmonary exercise testing out of concern that this test could worsen the patients’ symptoms. However, we found that cardiopulmonary exercise testing was able to identify reduced exercise capacity in about 45% of patients,” said Dr. Donna Mancini of the Icahn School of Medicine at Mount Sinai in New York. The 18 men and 23 women in the study all had persistent shortness of breath for more than three months after recovering from COVID-19, according to a report published on Monday in Journal of the American College of Cardiology: Heart Failure. They had normal-looking results on lung function tests, chest X-rays, chest CT scans and echocardiograms. The exercise tests revealed problems that would otherwise have been missed, Mancini said. “Low level functional testing recommended by the guidelines, such as a 6-minute walk test, would not be able to detect these abnormalities,” she said.

Experimental smartwatch COVID-19 detection improving

Smartwatch alerting systems for early detection of COVID-19 infection are coming closer to reality, researchers reported on Monday in Nature Medicine. They tested their new system, developed with open-source software, in 2,155 wearers of Fitbit, Apple Watch, Garmin watches or other devices. Ultimately, 84 of the volunteers were diagnosed with coronavirus infections – including 14 of 18 people without symptoms. Overall, the researchers’ algorithms generated alerts in 67 (80%) of the infected individuals, on average three days before symptoms began. “This is the first time, to our knowledge, that asymptomatic detection has been shown for COVID-19,” they said. Presently, the system mainly depends on measurements of wearers’ resting heart rate, said study leader Michael Snyder of Stanford University School of Medicine in California. Going forward, he said he hopes watch manufacturers will be able to provide other types of highly accurate physiologic data. “Many stressors can trigger the alerting,” Snyder said. “Most of these are easy to spot – travel, excessive alcohol, even work or other types of stress, so the user knows to ignore the alerts.” When watches can report other health data such as heart rate variability, respiration rate, skin temperature, and oxygen levels, it will become easier to distinguish the COVID-19 cases from other non-COVID-19 events, researchers said. “Right now we are running this as a research study,” Snyder said. “But soon we hope that FDA approved devices will dominate this area.”

(Reporting by Nancy Lapid; Additional reporting by Megan Brooks; Editing by Bill Berkrot)

Third-trimester vaccination appears safe; Pfizer/BioNtech vaccine effective in those with chronic illnesses

By Nancy Lapid

(Reuters) -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.

Third-trimester vaccination appears safe in early data

Among pregnant women who received COVID-19 vaccines manufactured by Pfizer Inc and BioNTech SE or Moderna Inc and who signed up for an online survey, side effects were no different than what has been seen in the general population, researchers reported Wednesday in The New England Journal of Medicine. But they noted that data of this nature is still sparse. They looked at responses from smartphone users who participated in the U.S. Centers for Disease Control and Prevention (CDC) “v-safe” program, which collects information on COVID-19 vaccination experiences. Compared to non-pregnant women, the 35,691 pregnant responders reported more injection site pain but fewer headaches, muscle aches, chills, and fevers. Among 3,958 women who signed up for a CDC pregnancy registry, no one vaccinated in the first trimester has given birth yet. The Vaccine Adverse Event Reporting System (VAERS), run jointly by the CDC and the U.S. Food and Drug Administration, has recorded 46 miscarriages potentially related to COVID-19 vaccination, including 37 in the first trimester, the researchers said. “Early data from the v-safe surveillance system, the v-safe pregnancy registry, and the VAERS do not indicate any obvious safety signals with respect to pregnancy or neonatal outcomes associated with Covid-19 vaccination in the third trimester of pregnancy,” researchers concluded.

Pfizer/BioNTech vaccine effective in people with chronic illnesses

The Pfizer/BioNTech COVID-19 vaccine is effective at preventing symptomatic and severe disease in people with some chronic illnesses, like diabetes and heart disease, according to a large real-world study published on Wednesday in The New England Journal of Medicine. The analysis of almost 1.4 million people, conducted by Clalit, Israel’s largest healthcare provider, showed the vaccine was 80% effective against symptomatic infection for people with heart or chronic kidney diseases, 86% for people with type 2 diabetes, 75% for cerebrovascular disease, and 84% for people suffering from immunodeficiency. For vaccinated people with at least three chronic conditions or risk factors, the vaccine was 88% effective in preventing symptomatic infection. It was more than 90% effective against severe disease for people with type 2 diabetes, heart or cerebrovascular disease. The results were lower than the 95% overall vaccine effectiveness observed after the second dose in clinical trials last year. “These results are very encouraging, as they suggest that most COVID-19 cases will be prevented by vaccination even in the elderly and chronically ill,” said Ran Balicer, Clalit’s chief innovation officer.

Fever, shortness of breath are COVID-19 red flags in pregnancy

Pregnant women with COVID-19 and their newborns face “consistent and substantial increases” in risks of complications, an international study has found. COVID-19 in newborns is associated with a three-fold risk of severe medical complications, according to the study by scientists at the University of Oxford. And pregnant women with symptomatic COVID-19 face higher risks of preterm delivery, preeclampsia (high blood pressure with organ failure risk), need for intensive care and death. That was particularly true for women with fever and shortness of breath, according to a report published on Friday in JAMA Pediatrics. “Women with COVID-19 during pregnancy were over 50% more likely to experience pregnancy complications compared to pregnant women unaffected by COVID-19,” said co-author Aris Papageorghiou. The study, conducted in 18 countries, included 706 pregnant women with COVID-19 and 1,424 similarly pregnant women without COVID-19 who were giving birth at the same hospital. Findings also showed a delivery by Caesarean section may be associated with an increased risk of virus infection in newborns. Breastfeeding, however, does not seem to heighten risks of transmission from mothers to babies, they found.

(Reporting by Nancy Lapid and Maayan Lubell; Editing by Bill Berkrot)