Millions of healthy young children will be vaccinated against swine flu, the UK Government has announced.

From next month children aged six months to five years will be offered the jab by their GP surgery.

Until now the vaccine has been targeted at pregnant women, frontline health workers and people with underlying health problems, such as asthma or diabetes, who are more vulnerable to the H1N1 virus.

The decision to extend it to healthy young people is based on scientific advice that children are among those most likely to contract swine flu and the highest rate of hospitalisations is in the under five age group.

Children are likely to receive half the usual adult dose of the vaccine, but experts are still finalising the exact quantity based on the latest trial data.

Scottish Health Secretary Nicola Sturgeon stressed the H1N1 vaccine was safe for children, saying it had been through the same safety checks as the seasonal flu vaccine which is offered every winter.

Ms Sturgeon said: “There is no reason for anyone to have any concerns about the safety of the vaccine. The greater risk to the majority of people is from the virus by a long, long shot.”

The 39th death from swine flu in Scotland was announced yesterday. The adult from the Lothians who died from the virus had an underlying health condition. A five-year-old girl from Slough in Berkshire was also confirmed to have died last night.

England’s Chief Medical Officer Sir Liam Donaldson said there had been a “very, very striking increase” in the number of under-fives admitted to hospital.

About 40 people have died worldwide after being inoculated against H1N1, but according to the World Health Organisation investigations so far show the fatalities were not caused by the vaccine.

The agency reaffirmed that the pandemic vaccine was safe and voiced concern that some pregnant women and others at risk were shunning it because of a fear of side effects.

More information about uptake rates in Scotland is due to be published next week.

Doctors are expected to start vaccinating children once they have covered those already eligible – such as those with long-term health problems.

Surgeries are receiving doses in batches and not enough stock has yet arrived to provide for all those in this top priority group.

There is some anxiety that announcing the extension of the vaccine programme to children will create a demand which doctors cannot meet.

Dr Alan McDevitt, joint deputy chairman of the Scottish General Practitioners Committee, said: “We are a bit concerned that the announcement will make people think if they phone up now we can give them the vaccine and the answer is we probably can’t.”

There are around 260,000 children aged six months to five years in Scotland and more than three million across the UK.

Discussions are currently taking place about offering carers, such as those looking after frail relatives, inoculation against H1N1.

Health Protection Scotland, which is monitoring the virus, estimates that around 21,200 people in Scotland have been infected within the past week. This is down from about 21,500 in the previous seven days.

Ms Sturgeon said the vast majority of young children, in common with the rest of the population, recover well from swine flu.

However, she said ministers had decided to vaccinate on the independent scientific advice of the Joint Committee on Vaccination and Immunisation.

Ms Sturgeon said: “Advice from the JCVI is that young children are more at risk of contracting the virus and the highest rate of hospitalisations has been in the under-five age group, so that is the key consideration.”