No trace of mRNA vaccine found in breast milk; gene found that helps identify COVID-19 early
July 19 (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 (PFE.N) and Moderna (MRNA.O) 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.
Click for a Reuters graphic on vaccines in development.
Reporting by Nancy Lapid and Megan Brooks; Editing by Bill Berkrot
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