The modern pharmaceutical company has started a study that will test its Covid vaccine on children under 12, including babies up to six months, the company said on Tuesday.
The study is expected to enroll 6,750 healthy children in the United States and Canada. Moderna did not say how many have signed up or received the first shots, according to spokeswoman Colleen Hussey.
“There is a huge demand to find out about vaccinating children and what it does,” said Dr. David Wohl, medical director of the vaccine clinic at the University of North Carolina, who is not involved in the study.
In a separate study, Moderna is testing its vaccine on 3,000 children aged 12 to 17 and may have results for that age group in the summer. The vaccine would then have to be authorized for use in children, so it would not be immediately available.
Many parents want protection for their children, and vaccinating children should help produce the collective immunity deemed crucial to stopping the pandemic. The American Academy of Pediatrics has called for expanding vaccine testing to include children.
Side effects of the vaccine, such as fever, pain in the arms, fatigue and pain in the joints and muscles, can be more intense in children than in adults, and doctors say it is important for parents to know what to expect after their children are vaccinated.
Each child in the Moderna study will receive two vaccines, 28 days apart. The study will have two parts. In the first, children aged 2 years and under 12 years can receive two doses of 50 or 100 micrograms each. Children under 2 years old can receive two injections of 25, 50 or 100 micrograms.
In each group, the first inoculated children will receive the lowest doses and will be monitored for reactions before later participants receive the highest doses.
Next, the researchers will perform a provisional analysis to determine which dose is safer and more likely to be protective for each age group.
Children in part 2 of the study will receive the doses selected by the analysis – or placebo injections consisting of salt water.
Moderna developed its vaccine in collaboration with the National Institute of Allergy and Infectious Diseases. The company and the institute are also working together on the study, together with the Federal Authority for Advanced Biomedical Research and Development.
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Children will be followed for a year to check side effects and measure levels of antibodies that will help researchers determine whether the vaccine appears to offer protection. Antibody levels will be the main indicator, but researchers will also look for coronavirus infections, with or without symptoms.
Dr. Wohl said the study looked well planned and probably efficient, but he questioned why children should be followed for just one year, when adults in the Moderna study are followed for two years. He also said he was somewhat surprised to see the vaccine being tested on children so young so early.
“Should we learn what happens to older children first before going to really young children?” Dr. Wohl asked. Most young children don’t get very sick from Covid, he said, although some develop a serious inflammatory syndrome that can be fatal.
Johnson & Johnson also said it would test its coronavirus vaccine on babies and young children, after testing it first on older children.
Pfizer-BioNTech is testing its vaccine on children aged 12 to 15 and said it plans to move to younger groups; the product is already authorized for use by people aged 16 and over in the United States.
Last month, AstraZeneca started testing its vaccine in Britain on children 6 years and older.