Heart inflammation after COVID-19 shots higher-than-expected in study of U.S. military

By Carl O’Donnell

(Reuters) – Members of the U.S. military who were vaccinated against COVID-19 showed higher-than-expected rates of heart inflammation, although the condition was still extremely rare, according to a study released on Tuesday.

The study found that 23 previously healthy males with an average age of 25 complained of chest pain within four days of receiving a COVID-19 shot. The incident rate was higher than some previous estimates would have anticipated, it said.

All the patients, who at the time of the study’s publication had recovered or were recovering from myocarditis – an inflammation of the heart muscle – had received shots made by either Pfizer Inc and BioNTech SE or Moderna Inc.

U.S. health regulators last week added a warning to the literature that accompanies those mRNA vaccines to flag the rare risk of heart inflammation seen primarily in young males. But they said the benefit of the shots in preventing COVID-19 clearly continues to outweigh the risk.

The study, which was published in the JAMA Cardiology medical journal, said 19 of the patients were current military members who had received their second vaccine dose. The others had either received one dose or were retired from the military.

General population estimates would have predicted eight or fewer cases of myocarditis from the 436,000 male military members who received two COVID-19 shots, the study said.

An outside panel of experts advising the U.S. Centers for Disease Control and Prevention (CDC) said last week that reports of myocarditis were higher in males and in the week after the second vaccine dose than would be anticipated in the general population. A presentation at that meeting found the heart condition turned up at a rate of about 12.6 cases per million people vaccinated.

Eight of the military patients in the study were given diagnostic scans and showed signs of heart inflammation that could not be explained by other causes, the study said. The patients in the study ranged from ages 20 to 51.

The CDC began investigating the potential link between the mRNA vaccines and myocarditis in April after Israel flagged that it was studying such cases in people who received the Pfizer/BioNTech vaccine there, and after a report that the U.S. military had also found cases.

Health regulators in several countries are conducting their own investigations.

(Reporting by Carl O’Donnell; Editing by Bill Berkrot)

‘Likely link’ between rare heart inflammation and Pfizer, Moderna vaccines -CDC advisers

By Michael Erman and Manojna Maddipatla

(Reuters) -Rare cases of heart inflammation in adolescents and young adults is likely linked to vaccination with the Pfizer/BioNTech and Moderna COVID-19 shots, a group of doctors advising the U.S. Centers for Disease Control and Prevention (CDC) said in a presentation released on Wednesday.

The COVID-19 Vaccine Safety Technical (VaST) Work Group said in their report that the risk of myocarditis or pericarditis following vaccination with the mRNA-based shots in adolescents and young adults is notably higher after the second dose and in males.

The CDC said in another report that the patients with heart inflammation following vaccination generally recover from the symptoms and do well.

The Advisory Committee on Immunization Practices (ACIP) is meeting on Wednesday to assess the possibility of a link between the heart condition and the mRNA vaccines. VaST is a sub-group of ACIP.

The CDC has been investigating cases of heart inflammation mainly in young men for several months. The Israeli health ministry earlier this month said it saw a possible link between such cases and Pfizer’s COVID-19 vaccine.

The CDC earlier this month said it was still evaluating the risk from the condition and did not confirm a causal relationship between the vaccines and the heart issue.

The agency, however, said a higher-than-expected number of young men have experienced heart inflammation after their second dose of the mRNA COVID-19 shots, with more than half the cases reported in people between the ages of 12 and 24.

Dr. Tom Shimabukuro, deputy director of the CDC’s Immunization Safety Office, said in a presentation that data from one of the agency’s safety monitoring systems – Vaccine Safety Datalink (VSD) – suggests a rate of 12.6 cases per million in the three weeks after the second shot in 12- to 39-year-olds.

ACIP will discuss the benefits of the mRNA vaccines versus the potential risk to adolescents and young adults from the heart condition, according to the agency’s agenda.

Although health officials in Israel have determined that there is likely a link between vaccination and the heart inflammation, concerns about the more infectious Delta coronavirus variant have prompted the country to urge 12-to 15-year old’s get vaccinated.

Pfizer, whose vaccine has been authorized for use in Americans as young as 12, previously said it had not observed a higher rate of heart inflammation than would normally be expected in the general population.

Moderna had said it could not identify a causal association with the heart inflammation cases and its vaccine.

Over 138 million Americans have so far been fully vaccinated with one of the two mRNA vaccines, according to CDC data as of Monday.

(Reporting by Michael Erman in New Jersey and Manojna Maddipatla in Bengaluru; Editing by Bill Berkrot)

Pfizer to test COVID-19 vaccine in larger group of children below 12

By Michael Erman and Ankur Banerjee

(Reuters) – Pfizer Inc said on Tuesday it will begin testing its COVID-19 vaccine in a larger group of children under age 12 after selecting a lower dose of the shot in an earlier stage of the trial.

The study will enroll up to 4,500 children at more than 90 clinical sites in the United States, Finland, Poland and Spain, the company said.

Based on safety, tolerability and the immune response generated by 144 children in a phase I study of the two-dose shot, Pfizer said it will test a dose of 10 micrograms in children between 5 and 11 years of age, and 3 micrograms for the age group of 6 months to 5.

A Pfizer spokesperson said the company expects data from 5- to 11-year-olds in September and would likely ask regulators for emergency use authorization later that month. Data for children 2 to 5 years old could arrive soon after that, he said.

Pfizer expects to have data from the 6-month to 2-year-old age group sometime in October or November.

The vaccine – made by Pfizer and German partner BioNTech SA – has been authorized for use in children as young as 12 in Europe, the United States and Canada. They receive the same dose as adults: 30 micrograms.

Nearly 7 million teens have received at least one dose of the vaccine in the United States, according to the U.S. Centers for Disease Control and Prevention.

Inoculating children and young people is considered a critical step toward reaching “herd immunity” and taming the COVID-19 pandemic.

Still, scientists in the United States and elsewhere are studying the possibility of a link between heart inflammation and mRNA vaccines, particularly in young men. Both Pfizer and Moderna Inc’s vaccines are mRNA shots.

Israel’s Health Ministry said last week it had found the small number of myocarditis cases observed mainly in young men who received the Pfizer vaccine there were probably linked to their vaccination. The cases were generally mild and did not last long.

Pfizer has said it is aware of the Israeli observations of myocarditis and that no causal link to its vaccine has been established.

(Reporting by Ankur Banerjee in Bengaluru and Michael Erman in New York; Editing by Arun Koyyur, Will Dunham and Mark Heinrich)

More unvaccinated U.S. adolescents hospitalized; myocarditis may be rare vaccine side effect in teens

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.

COVID-19 hospitalizations up among U.S. adolescents

COVID-19 hospitalizations rose among U.S. adolescents in March and April, and nearly a third of those hospitalized needed intensive care, according to data from more than 250 hospitals in 14 states released by the Centers for Disease Control and Prevention (CDC) on Friday. “Rates of COVID-19-associated hospitalization among adolescents also exceeded historical rates of seasonal influenza-associated hospitalization during comparable periods,” researchers reported in the CDC’s Morbidity and Mortality Weekly Report. The hospitals reported a total of 204 adolescents hospitalized for COVID-19 in March and April. “Until they are fully vaccinated, adolescents should continue to wear masks and take precautions when around others who are not vaccinated to protect themselves, and their family, friends, and community,” CDC Director Rochelle Walensky said in a statement on Friday. “I ask parents, relatives and close friends to join me and talk with teens about the importance of these prevention strategies and to encourage them to get vaccinated.”

Heart inflammation may be rare vaccine side effect in teens

Temporary heart inflammation may be a rare side effect of the Pfizer/BioNTech COVID-19 vaccine in teenagers, according to pediatricians who reported on seven cases from across the United States. The previously healthy adolescents – all boys – developed chest pain within four days after their second dose. MRI exams showed myocarditis, or heart muscle inflammation. “Fortunately, none of our patients was critically ill,” the authors reported on Friday in Pediatrics. The boys’ symptoms resolved “rapidly” with medication. Measures of cardiac status had returned to normal at check-ups performed after one-to-three weeks. Myocarditis is a known rare adverse event following other vaccinations, the authors noted. There is no proof, however, that the vaccine caused these cases. “So far, over 2.2 million teenagers (aged) 16-17 have already received 2 doses of Pfizer vaccine, and over 3 million kids 12-15 years old have received dose #1,” said coauthor Dr. Judy Guzman-Cottrill of Oregon Health & Science University. “These are huge, very reassuring denominators.” COVID-19 itself can cause myocarditis, she noted. “After looking at the risks and benefits, the data support getting kids vaccinated.”

Measuring longer-lasting COVID-19 immunity feasible

Along with testing for antibody levels after COVID-19 or vaccination to gauge a person’s immunity to the virus, measuring the response of the immune system’s T cells could provide important information, according to researchers based at Cardiff University. While antibody levels wane over time, T cell responsiveness can last for months or years. But T cells have been harder to measure in cost-effective ways. Adapting a method widely employed to measure immune responses to other types of infections, the researchers took blood samples from adults and children and stimulated T cells with small proteins specific to the SARS-CoV-2 virus. T cells that recognize these proteins, because the person has been previously infected or vaccinated, “are triggered to produce chemicals like interferon which can be easily measured,” said study coauthor Andrew Godkin. The results were about 96% accurate, researchers reported on Tuesday on medRxiv ahead of peer review. “The test is very sensitive and seems to be accurate at identifying people previously exposed to the virus,” Godkin said. “The test is widely available, easy to employ, and should play a very useful role in monitoring this pandemic.”

Virus unlikely to insert genetic fragments into patients’ genetic code

A new study refutes the controversial claim made by researchers last month in PNAS that small fragments of genetic instructions from the coronavirus became integrated into the genome of infected cells, in test tube experiments. In principle, coronavirus RNA generated by such integrated snippets, while probably not harmful, might cause positive COVID-19 PCR tests long after a patient has recovered, the authors of that study said. But when researchers in Australia sought to find signs of SARS-CoV-2 genetic code integrated into the DNA of infected cells, they could not find any. “This was despite using the same sequencing technology and cell type (as in the PNAS study) and performing substantially more DNA sequencing,” said Geoffrey Faulkner of the University of Queensland. The new finding were posted on Sunday on bioRxiv ahead of peer review. The researchers did find copies of hepatitis B virus integrated into liver tissue, and copies of other DNA elements integrated into the cells they experimented with, “suggesting our approach would have found SARS-CoV-2 copies” if they were present, he said. His team agrees with others who suggest the PNAS findings may have reflected unintended effects of experimental methods. “We think SARS-CoV-2 integration into DNA is possible in human cells even if it is likely to be incredibly rare in patients,” Faulkner said.

(Reporting by Nancy Lapid and Christine Soares; Editing by Bill Berkrot)