A new flu vaccine that contains pork gelatine is kosher, rabbis have said.

The nasal spray vaccine Fluenz is being given to millions of toddlers and children across the UK this autumn.

Under a vaccination programme, all children aged two or three on September 1 2013, as well as 200,000 children aged four to 10 in seven trial areas, will receive the spray.

The vaccine, which is new to the UK, but has been used in the United States for 10 years, contains a hydrolysed porcine gelatine, which is used to stabilise the live vaccine.

The treatment is deemed more effective than the traditional flu injection because it is delivered in the same way the real flu virus is, by breathing it in.

We have told schools that parents have nothing to worry about

Rabbi Abraham Adler from the Kashrus and Medicines Information Service, who has advised the government on kashrut issues, said: “According to Jewish laws, there is no problem with porcine or other animal derived ingredients in non-oral products. This includes vaccines, including those administered via the nose, injections, suppositories, creams and ointments.”

Rabbi Yehuda Brodie, registrar of the Manchester Beth Din, agreed, calling the vaccine “absolutely acceptable”.

He said: “We have already told schools in the Manchester area that parents have nothing to worry about.”

Trial areas for the four- to 10-year-olds include Gateshead and the London borough of Newham. The NHS plans eventually to roll out the programme to include all children and teenagers under 17.

GPs will administer the spray to two- and three-year-olds, while 200,000 older children in the trial areas will receive it in schools from NHS staff. Parents whose children are invited to be vaccinated will receive a letter by the end of October.