Moderna said it would expand an ongoing trial of its coronavirus vaccine in children under 12 years old to gather more safety data amid worries that messenger RNA shots may trigger rare heart side effects.
“The objective is to enrol a larger safety database which increases the likelihood of detecting rarer events,” a Moderna spokesperson said.
Clinical trial timelines are regularly re-evaluated based on regulatory agency discussions and requests, she said, and Moderna expects to have data that would support authorisation in late 2021 or early 2022. The company is discussing a proposal for a bigger trial with the US Food and Drug Administration, she said.
The more you vaccinate, the more you’re likely to see rare side effects. Though including more patients may delay approval for that age group, it will instill a sense of security and safety for the intended population.
Concerns about side effects from the Moderna and Pfizer-BioNTech SE mRNA-based vaccines have risen after reports of rare cases of heart and heart-lining inflammation in young adults.
Federico Laham, medical director for children’s infectious diseases at Orlando Health Arnold Palmer Hospital for Children in Florida, said expanding the size of the trials for the under-12 age group will help families weigh the benefits and risks of vaccination.
“I welcome this cautious approach,” he said. “The more you vaccinate, the more you’re likely to see rare side effects. Though including more patients may delay approval for that age group, it will instil a sense of security and safety for the intended population.”
The New York Times reported earlier on Monday that both Moderna and the Pfizer-BioNTech partnership were expanding the size of their paediatric Covid vaccine trials at the request of the FDA. Pfizer declined to comment on whether its trial had got bigger.
FDA spokesperson Abby Capobianco said the agency generally works with companies to ensure that clinical trials are of adequate size to detect safety signals, but declined to comment on the vaccine trials specifically.
Moderna’s late-stage children’s trial began in March and was originally planned to enrol 6,750 participants aged from six months old to 11 years old. A listing on clinicaltrials.gov projects 6,975 participants. The company said it couldn’t confirm the scope of the expansion.
In recent weeks, US health agencies have convened panels to discuss the rollout of vaccines to children. Pfizer and BioNTech’s was cleared for those age 12 and up in May.
Moderna’s vaccine is authorised for adults ages 18 and older. It is awaiting an FDA decision on expansion to 12 and up, and the shot has already been recommended for use in that age group by the European Medicines Agency.
Paediatricians have taken a more cautious tone on the two-shot regimens for use in even younger children, particularly in the wake of reports about rare side effects.
In June, advisers to the US Centers for Disease Control and Prevention met to discuss a potential link between mRNA-based Covid vaccines and cases of both heart inflammation, called myocarditis, and inflammation of the membrane around the heart, or pericarditis. A total of 1,226 cases were reported through June 11, according to the CDC, most of which were among young men and adolescents.
After the meeting, US public-health leaders sought to reassure Americans that Covid-19 shots are safe and to get vaccinated. They suggested the risk potentially posed by the shots is extremely low, and that it is much more likely that the coronavirus itself would pose a serious health threat.
Should the US shift its policy on the size of paediatric studies, that would have an immediate impact on Pfizer and BioNTech’s under-12 trial.
In early June, the companies began testing the vaccine – at a third of the typical dose – in those aged between five through 11. Later that month, they began testing one-tenth of the typical dose in those younger than five. Altogether, the clinical trial aims to enrol 4,500 children. Initial data from children aged five to 11 is expected in September, clearing the way for a potential US authorisation before the end of the year.
Moderna is also studying lower doses of its vaccine in children.
Anthony Fauci, the top US infectious disease specialist, has said he expected children of any age to be able to get their vaccines within the first quarter of 2022. The White House is already making preparations for such a campaign, purchasing 65 million doses of the Pfizer-BioNTech shot specifically for children under 12. Some of those shots would be immediately available upon authorisation.
– Bloomberg News. More stories like this are available on bloomberg.com
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