Moderna’s Covid-19 vaccine appears safe and powerfully effective in teens

Backstory: FDA authorized Moderna’s Covid-19 vaccine for use in adults 18 and older in December 2020. The company began trials in teens and children earlier this year.

Though teenagers are less likely to develop severe Covid-19 compared to adults, health experts say that vaccinating children aged 12 to 17 is key to culling the pandemic.

Over 3,700 teenagers participated in Moderna’s Phase II/Phase III trial. Two-thirds of them received the vaccine, while one third received a placebo. There were no cases of symptomatic Covid-19 among the vaccinated group starting two weeks after the final shot. There were four cases in the placebo group.

The study also looked at even milder cases of Covid-19 in participants, which present with only one symptom and a positive molecular test for the SARS-CoV-2 virus. When considering these Covid-19 cases, the vaccine was 93 percent effective after the first of two doses.

The side effects reported were minimal and similar to other vaccinations. Some participants reported pain at the site of the injection after the first dose, while others experienced mild to moderate headaches, muscle aches, and fever chills.

What’s next: Moderna will seek authorization from FDA as early as next week to use its vaccine in teens. An independent safety monitoring board will continue to monitor participants up to a year after they received their doses to ensure the vaccine’s safety.