Mass vaccination of children against Covid-19 moved a step closer as Moderna became the second manufacturer to announce successful trial results, showing its vaccine can stop transmission in people aged 12 to 18.
Pfizer/BioNTech’s vaccine has already been given emergency approval for adolescents aged 12 to 15 in the US by the regulator, the Food and Drug Administration (FDA), after its trials were said to show better efficacy even than in participants aged 16 to 25. It has begun a trial in young children, from six months to 11 years old.
The results from both companies suggest that mass immunisation of schoolchildren could be on the cards this year, beginning in the US, which could in theory end the anxieties of parents, pupils and teachers and allow schools to function more normally. Pfizer applied for emergency use authorisation for 12- to 15-year-olds in Europe at the end of April.
AstraZeneca began the first trial to use a Covid vaccine in children from the age of six in February, aiming to enrol 300 volunteers aged six to 18 across four sites in London, Oxford, Bristol and Southampton.
Like Pfizer, Moderna says its vaccine, formally called mRNA-1273, was 100% effective in trials in young people. In a trial of 3,700 young people aged 12 to 18, there were no symptomatic cases of Covid-19 among those who received two doses of the vaccine.
Because there are fewer cases among children, they also looked at the US Centers for Disease Control and Prevention’s definition, which includes milder cases. Applying the CDC definition of just one symptom plus a positive Covid swab test, they recorded 93% efficacy after one dose.
The company says there were no serious side-effects, which were limited to sore arms and headaches, fatigue, myalgia (muscle pain) and chills after the second dose. All those who took part will be monitored for the next 12 months to be sure there are no longer-term effects.
“We are encouraged that mRNA-1273 was highly effective at preventing Covid-19 in adolescents. It is particularly exciting to see that the Moderna Covid-19 vaccine can prevent Sars-CoV-2 infection,” said Stéphane Bancel, the chief executive of Moderna.
“We will submit these results to the US FDA and regulators globally in early June and request authorisation. We remain committed to doing our part to help end the Covid-19 pandemic.”