NEW YORK • In the United States, more than 14 million Covid-19 vaccines have been given since last month, mainly to healthcare workers, the elderly and those facing a high risk of contracting the virus.
To defeat the pandemic and fully revive the economy, children will also have to be immunised, experts say. To that end, trials to ensure that vaccines are safe for the young are beginning in earnest.
Pfizer-BioNTech and Moderna started recruiting participants at the end of last year. The University of Oxford, which developed its vaccine with AstraZeneca, is planning initial tests next month.
"If you want to get this under control, you need to vaccinate kids," said chief scientific officer Paul Stoffels from Johnson & Johnson. He estimated that trials for kids would start four to six weeks after receiving results from its adult studies, which are expected by early next month.
Pfizer's vaccine trial has 2,000 volunteers aged 12 to 15, said lead investigator John Vanchiere for the trial site at Louisiana State University Health Shreveport.
Moderna and its partners at the US National Institutes of Health had "recruited about 800 subjects in the trial". The plan was to have 3,000 aged 12 to 18. A spokesman said it expects a pickup in enrolment and is on track to give updated data by around mid-year.
Oxford plans to recruit about 120 kids in both the 12-to-18 and six-to-11 age groups, said lead investigator Andrew Pollard. AstraZeneca will then run a larger trial for kids in the US. It declined to provide details on the study size or timing.
Governments around the world have repeatedly shut schools, burdening working parents and the economy. While kids do not generally suffer from severe Covid-19, inoculating them could reduce the spread to people at higher risk.
How quickly vaccines will be rolled out for children may depend on how much data scientists can gather on the role they play in transmission, and how much vaccines can stop the spread. Little is known so far about either.
The main driver for Covid-19 child vaccinations is achieving herd immunity, said Professor Beate Kampmann, director of the London School of Hygiene and Tropical Medicine's vaccine centre. That is unlikely to be achieved if more than a quarter of the global population is unprotected.
A vaccine for children could mean a return to normalcy. "It's important for this age group to get vaccinated so that they can go back to school," said Mrs Lisa Brown, mother of William Brown, 15. He has yet to set foot in a classroom during his freshman year of high school.