Although children are at a much lower risk of severe Covid-19 than the elderly, that risk is not completely negligible – especially in children with an underlying condition. Vaccines for the 5-11 age group have now also been studied – and have been shown to be safe and effective. The trial by Pfizer-BioNTech (N Engl J Med. 2022;386:35-46) showed about 90% effectiveness of 2 injections against a SARS-CoV-2 infection, but took place during the period when the delta variant in particular circulated.
Recently, studies from Israel (N Engl J Med. 2022; online June 29) and Italy (Lancet. 2022; online June 20) have been published that analyzed the ‘real world’ effectiveness of vaccination in children during a period when the omikron variant was dominant. became. The Israeli and Italian vaccination campaigns for children aged 5-11 started in November and December 2021 respectively.
The Israeli researchers matched 94,728 children with no history of SARS-CoV-2 infection to an unvaccinated child on the day of vaccination. They matched on age, gender and number of chronic conditions, among other things. The efficacy of vaccination against documented SARS-CoV-2 infection and symptomatic Covid-19 was 51% (95% CI: 39-61) and 48% (95% CI: 29) 7-21 days after the second dose, respectively. -63). The younger the children were, the higher the effectiveness.
In Italy, in the period January 17 to April 13, 2022, about 34% of children aged 5-11 had received both vaccine doses. From a national database from that period, the researchers included nearly 3 million children who had no history of SARS-CoV-2 infection. More than 1 million of them were fully vaccinated. After adjusting for age, gender and regional weekly covid-19 incidence, the effectiveness of vaccination was 29.4% (95% CI: 28.5-30.2) against documented SARS-CoV-2 infection and 41.1% (95% CI: 22.2-55.4) against severe covid-19. Efficacy against infection was highest 0-14 days after the second vaccination (approximately 39%) and declined steadily thereafter.
In the Netherlands, however, few children have been vaccinated against Covid-19: currently, according to RIVM, about 4% of children born in the period 2010-2016.