London, Sep 14 : Children aged 12 to 15 will be offered the Covid-19 vaccine, Chief Medical Officers (CMOs) of Britain's all four nations have confirmed. England's CMO Chris Whitty said on Monday that they came to their decision after considering "what effect this will have on transmission in schools and effects on education", Xinhua news agency reported. "It's a useful tool to reduce the disruption," he added. It is expected the vaccinations will be given through school immunisation programme. Healthy children aged 12 to 15 will be offered a single dose of the Pfizer vaccine and the rollout should begin "as soon as possible", England's deputy CMO Jonathan Van-Tam was quoted by local media as saying. There are concerns of a rise in cases following children's return to school after the summer holiday. The latest decision takes into account the impact of the pandemic on children's education as well as the risks to their mental health from missing school. The move means that around 3 million children could be eligible for the jab and comes despite Britain's vaccine advisory body deciding not to recommend mass vaccination of 12 to 15-year-olds. "They are particularly effective as 'vectors', transmitting the infection between households. Now that the much more infectious Delta variant is prevalent we will struggle to control the virus with vaccination alone -- and we certainly won't succeed if this age group is unvaccinated," said Peter English, immediate past chair of the Public Health Medicine Committee of the British Medical Association. Previously, Britain's vaccine advisory body, the Joint Committee on Vaccination and Immunisation (JCVI), has issued the advice that children aged 12 to 15 with medical conditions should receive two doses of the Covid-19 vaccine, but that healthy children in this age group should still not receive the Covid-19 vaccine. In its advisory report, the JCVI said the "individual" health benefits from vaccination for children aged 12 to 15 was marginal, while the risk of potentially serious side effects, including myocarditis, is "very rare, but potentially serious". More than 89 per cent of people aged 16 and over in Britain have had their first dose of vaccine and nearly 81 per cent have received both doses, the latest figures showed. To bring life back to normal, countries such as Britain, China, Germany, Russia and the United States have been racing against time to roll out coronavirus vaccines. /IANS