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)

Lack of side effects doesn’t mean mRNA vaccine not working; mRNA shots limit breakthrough infection severity

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.

Lack of vaccine side effects no cause for concern

While a variety of side effects after receiving an mRNA COVID-19 vaccine may be a sign of the immune system kicking into high gear, a lack of such reactions does not mean it has failed to respond, researchers have found. They tested 206 hospital employees for antibodies against the coronavirus before and after receipt of the vaccine from Pfizer and BioNTech and surveyed them about vaccine-related reactions. As in clinical trials, arm pain was the most common symptom, reported by 91% after the first shot and 82% after the second. Systemic symptoms, such as feeling weak or tired, or having body aches or pains, were reported by 42% and 28%, respectively, after the first shot and by 62% and 52% after the second shot. But there was no correlation between vaccine symptom severity and antibody levels one month after vaccination, the researchers reported on Friday in a paper posted on medRxiv ahead of peer review. The researchers said the findings should reassure people that a lack of side effects after getting the mRNA shots does not mean the vaccine is not working as intended. The Moderna shot also uses mRNA technology.

mRNA vaccines limit severity of rare breakthrough infections

In the rare cases of COVID-19 that occur after vaccination, patients are likely to be sick for less time and have milder symptoms than if they were unvaccinated, according to a U.S. study of nearly 4,000 healthcare personnel, first responders, and other frontline workers. In participants who were tested weekly since mid-December, COVID-19 has been diagnosed in five who were fully vaccinated with an mRNA vaccine from either Pfizer and BioNTech or Moderna, 11 who were partially protected, having received either one shot or were less than 14 days out from their second, and 156 who were unvaccinated. Most unvaccinated patients were sick for at least two weeks, compared with only one week for vaccinated patients, the researchers reported on Wednesday in The New England Journal of Medicine. Patients who were fully or partially vaccinated had 58% lower odds of fever and spent an average of 2.3 fewer days in bed than unvaccinated patients. Their viral loads also averaged 40% lower. “If you get vaccinated, about 90% of the time you’re not going to get COVID-19,” coauthor Dr. Jeff Burgess of the University of Arizona said in a statement. “Even if you do get it, there will be less of the virus in you and your illness is likely to be much milder.”

J&J vaccine shows promise against Delta variant in lab test

The single-shot COVID-19 vaccine from Johnson & Johnson showed promise against the highly contagious Delta coronavirus variant in a laboratory study posted on Thursday on bioRxiv ahead of peer review. Analyses of blood from eight recipients of the vaccine showed that its neutralizing antibody activity against the Delta variant, first identified in India, was reduced by 1.6-fold compared to an earlier version of the virus but is still higher than against the Beta variant, first identified in South Africa. In trials last year while the Beta variant was circulating in South Africa, the J&J vaccine showed 66% efficacy against moderate and severe disease. “We believe that our vaccine offers durable protection against COVID-19 and elicits neutralizing activity against the Delta variant,” J&J Chief Scientific Officer Paul Stoffels said. So far, preliminary data has shown that vaccines made by Pfizer and BioNTech, AstraZeneca and Moderna are largely protective against Delta, with the concentration of virus-neutralizing antibodies being somewhat reduced. Delta has become the variant of most concern around the world as it is more easily transmitted, may lead to more severe disease even in younger people, and is becoming the dominant virus version in many countries.

High COVID-19 rate seen in patients’ pets

In 20% of households where humans had COVID-19 or had recovered from it, cats and dogs also had antibodies to the virus, researchers from The Netherlands found. They visited 196 households where humans had tested positive within the previous 200 days, to test pet cats and dogs for the coronavirus and for antibodies that would indicate past infection. Thirteen animals – six cats and seven dogs – or 4.2%, had COVID-19, and 54 – 31 cats and 23 dogs (17.4%) – had coronavirus antibodies. There was no evidence that pets were passing the infection to each other. Owners reported no or mild symptoms in the infected animals. “If you have COVID-19, you should avoid contact with your cat or dog,” Dr. Els Broens of Utrecht University, whose team presented the data on Wednesday at the European Congress of Clinical Microbiology & Infectious Diseases, said in a statement. “The main concern, however, is not the animals’ health … but the potential risk that pets could act as a reservoir of the virus and reintroduce it into the human population.” To date, however, no pet-to-human transmission has been reported, he added. “It seems unlikely that pets play a role in the pandemic.”

(Reporting by Nancy Lapid, Aakriti Bhalla and Manas Mishra; Editing by Bill Berkrot)