Sleep apnea linked to COVID-19 outcomes

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 have yet to be certified by peer review.

Sleep apnea tied to severe COVID-19

The risk of severe illness from COVID-19 is higher in people with obstructive sleep apnea and other breathing problems that cause oxygen levels to drop during sleep, researchers say. They tracked 5,402 adults with these problems and found that roughly a third of them eventually tested posted for the coronavirus. While periodic episodes of not-breathing while asleep – leading to low oxygen levels, or hypoxia – did not increase people’s chances of being infected, sleep-related hypoxia did increase infected patients’ odds of needing to be hospitalized or dying from COVID-19, Drs. Cinthya Pena Orbea and Reena Mehra of the Cleveland Clinic and colleagues reported on Wednesday in JAMA Network Open. It is not clear if treatments that improve sleep apnea, such as CPAP machines that push air into patients’ airways during sleep, would also reduce the risk of severe COVID-19, said Pena Orbea and Mehra.

Body’s coronavirus memory may abort new infections

Healthcare workers who did not test positive for COVID-19, despite heavy exposure to infected patients, had T cells that attacked a part of the virus that lets it make copies of itself, according to a report published Wednesday in Nature. Researchers who studied the 58 healthcare workers found their T cells responded more strongly to a part of the virus, called the RTC, that is very similar on all human and animal coronaviruses, including all variants of SARS-CoV-2. They suspect the T cells recognized the RTC because they had “seen” it on other viruses during other infections. That makes the RTC a potentially good target for vaccines if more research confirms these findings, study leaders Mala Maini and Leo Swadling, both of University College London, said in a joint email to Reuters. These data were collected during the first wave of the pandemic, they added. “We don’t know if this sort of control happens for more infectious variants currently circulating.”

Vaccines induce neutralizing antibodies in breast milk

Infants might benefit from COVID-19 antibodies in breast milk regardless of whether mothers acquired the antibodies from being infected with SARS-CoV-2 or from vaccines, according to new findings reported on Wednesday in JAMA Pediatrics. Researchers studied antibodies in breast milk samples from 47 mothers who had been infected with the virus and 30 healthy mothers who had received the vaccines from Moderna or Pfizer/BioNTech. Antibodies from both groups were able to neutralize active SARS-CoV-2 virus, and while antibodies from infection were evident in milk for longer periods, antibody levels from vaccination “were much more uniform,” said study leader Bridget Young of the University of Rochester School of Medicine and Dentistry in New York. Thus, there is likely benefit to getting vaccinated even after a COVID-19 infection because breast milk would then contain a diverse variety of antibodies, she said. The researchers did not study the effect of the antibodies on the babies who consumed the milk.

(Reporting by Nancy Lapid; Editing by Tiffany Wu)

No trace of mRNA vaccine found in breast milk; gene found that helps identify COVID-19 early

By Nancy Lapid

(Reuters) – Here 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.

No trace of vaccines’ mRNA seen in breast milk

No traces of mRNA vaccines end up in mothers’ breast milk, a small study suggests. The COVID-19 vaccines from Pfizer/BioNTech and Moderna deliver a synthetic version of messenger RNA molecules, designed to instruct cells to build replicas of the coronavirus spike protein. The immune system then learns to recognize the spike and produce antibodies to attack it, while the messenger RNA quickly breaks down into inert pieces. While these beneficial antibodies may pass from mothers to infants via breast milk, the milk does not contain the mRNA itself, researchers found in their analyses of 13 breast milk samples from seven vaccinated women. The World Health Organization recommends that breastfeeding mothers be vaccinated against COVID-19 and does not advise stopping breastfeeding afterward. Many mothers have declined vaccination or discontinued breastfeeding due to concern that the vaccine may alter breast milk. Writing in JAMA Pediatrics, the authors of the new study said more data is needed to better estimate the vaccines’ effect on breastfeeding. But the new results “strengthen current recommendations that the mRNA vaccines are safe in lactation, and that lactating individuals who receive the COVID vaccine should not stop breastfeeding,” coauthor Dr. Stephanie Gaw of the University of California, San Francisco, said in a statement.

Researchers find gene that helps identify COVID-19 cases

A gene called IFI27 that becomes activated early in COVID-19, even when symptoms are absent, might help identify people most likely to have contracted the virus after coming in contact with an infected person, researchers said. Four hundred UK healthcare workers completed weekly questionnaires about COVID-19 symptoms and provided blood samples and nasal swabs for PCR testing for six months. In 41 workers diagnosed with COVID-19, IFI27 genes were “switched on” at the time of their first positive PCR test, even in asymptomatic individuals, according to a report in The Lancet Microbe. In some cases, IFI27 could predict infection one week before a positive PCR test, said coauthor Joshua Rosenheim of University College London. Overall, testing for IFI27 correctly identified 84% of COVID-19 cases and correctly ruled it out in 95% of uninfected participants. Blood biomarkers like IFI27 can signal other viruses as well, so PCR is still the gold standard for diagnosing COVID-19. “However, testing for blood biomarkers is still valuable,” Rosenheim said. “IFI27 predicted infection despite the person not having any symptoms and often before a positive PCR test, so it could be used during contact tracing.” IFI27 tests in people who recently came in contact with a confirmed COVID-19 patient could allow for earlier diagnosis and treatment and “might even permit us to recommend self-isolation in a more targeted manner.”

Intranasal vaccine aims to block virus at point of entry

An experimental intranasal COVID-19 vaccine now being tested for the first time in humans showed promising results in monkeys, researchers will report on Thursday at ASV 2021, the annual meeting of the American Society of Virology. The protection provided to the primates by a single dose of the vaccine from Meissa Vaccines was equivalent to the protection provided by currently authorized vaccines, according to a news release from the company. Like injected vaccines, the intranasal vaccine, which is administered via drops or spray into the nose, stimulates the body to produce antibodies that circulate in the blood. But the intranasal vaccine also stimulates production of antibodies on mucosal surfaces that line the airways, which is where the virus first makes contact and enters the body, the research team reported in a paper seen by Reuters and submitted for posting ahead of peer review on the bioRxiv preprint server. The pilot study in humans, which got underway in March, is expected to enroll 130 volunteers to evaluate the safety, tolerability and immune system effects of various doses of the vaccine. Once it selects a safe dose likely to be most effective against the virus, the company will need to conduct larger and more rigorous trials. “We believe Meissa’s intranasal COVID-19 vaccine has the potential to be an important part of the endgame solution to contain SARS-CoV-2,” Roderick Tang, chief scientific officer of Meissa Vaccines, said in a statement.

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

Post vaccination infection rare but possibly contagious; study refutes another anti-vax pregnancy claim

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.

Breakthrough infections rare, but potentially contagious

As of April 30, when roughly 101 million Americans had been fully vaccinated against COVID-19, “breakthrough” infections had been reported in 0.01% of them, the U.S. Centers for Disease Control and Prevention (CDC) reported on Tuesday. Roughly 27% of breakthrough infections were asymptomatic, while in 2% of cases, patients died. The CDC had genetic data for virus samples from 555 breakthrough infections. Mutated variants of the coronavirus, including those first seen in the UK and South Africa, accounted for 64% of the breakthroughs. In a separate study posted Tuesday on medRxiv ahead of peer review, researchers reported that among 20 fully-vaccinated healthcare workers with breakthrough COVID-19 cases, all were infected with variants. An earlier study had linked breakthrough infections with low viral loads, suggesting low transmission risks, but “we found many samples in our breakthrough cohort with high viral load,” said coauthor Pavitra Roychoudhury of the University of Washington. “Our work suggests that not all breakthrough infections are at low risk of initiating transmission and, if they did, these infections could lead to the continued spread of variants of concern, particularly in areas with low vaccination rates.”

Study refutes anti-vaxxers’ pregnancy, breast milk claims

Unfounded claims by anti-vaccine activists that COVID-19 shots from Pfizer/BioNTech and Moderna will damage the placenta and contaminate breast milk have been refuted by new data. The vaccines deliver synthetic messenger RNA (mRNA), which instructs the body to make proteins that in turn induce antibodies to attack the coronavirus. Anti-vaxxers claim, with no evidence, that mRNA also induces antibodies that attack a protein called syncytin-1, which is important for the developing placenta during pregnancy. They also claim mRNA from the vaccines ends up in breast milk. When researchers studied blood samples from 15 women who received at least one dose of the Pfizer/BioNTech vaccine – including two pregnant women and five who were breastfeeding – they saw coronavirus antibodies but no antibodies against syncytin-1. None of the breastfeeding women had vaccine mRNA in their milk, according to a report posted Tuesday on medRxiv ahead of peer review. “This small study tells us that it is unlikely that COVID-19 mRNA vaccination will cause complications in pregnancy or fertility through cross-reacting antibodies against syncytin-1, or for breastfed infants through breast milk,” the authors said.

Vaccines appear safe for “long COVID” survivors

COVID-19 survivors with lingering symptoms can safely be vaccinated against the coronavirus, a small study suggests. Researchers tracked 36 individuals with “long COVID” who had been hospitalized while acutely ill and who later received at least one dose of either the Pfizer/BioNTech or AstraZeneca vaccine. Eight months after admission to the hospital, and before vaccination, participants had at least one lingering symptom and half had at least four symptoms. Before vaccination, their quality-of-life was “markedly reduced” from normal, the researchers reported on Monday in Annals of Internal Medicine. One month after vaccination, 71% of their symptoms remained unchanged, 23% of their symptoms were improved, and 6% of symptoms had worsened. There was no significant worsening in quality-of-life or mental well-being, and outcomes were similar with both vaccines, researchers reported. The results may reassure people with persistent COVID-19 symptoms that the different types of vaccines developed by Pfizer/BioNTech or AstraZeneca are “not associated with a decrease in quality of life or worsening of symptoms,” the researchers said.

Moderna says vaccine safe, effective in adolescents

Moderna’s COVID-19 vaccine was 100% effective in a trial involving 3,732 adolescents aged 12-17, with no major safety problems, the company said on Tuesday. Among participants who received two doses, there were no cases of COVID-19 compared with four cases among those who received a placebo. After only one dose, the vaccine was 93% effective in this age group, Moderna said. Side effects were similar to those reported in earlier studies, including headache, fatigue, body aches and chills. Moderna plans to submit the findings to regulators for emergency use authorization in June. The U.S. Centers for Disease Control and Prevention (CDC) said on Monday it is monitoring rare reports of mild heart inflammation after COVID-19 vaccination in adolescents. The CDC said the condition is not occurring at higher rates than would be expected in the general population, so no causal link to the vaccine has been established. Dr. Amesh Adalja of the Johns Hopkins Center for Health Security said even if vaccines turn out to be the cause, it is important to consider the risk-benefit ratio. “Vaccines are going to unequivocally be much more beneficial,” outweighing any low risk of myocarditis, he said.

(Reporting by Nancy Lapid, Julie Steenhuysen and Radhika Anilkumar; Editing by Bill Berkrot)