JERUSALEM, Nov 22 (Reuters) - Israel began rolling out Pfizer-BioNtech COVID-19 vaccinations for 5-to-11-year-olds on Monday (Nov 22) hoping to beat down a recent rise in coronavirus infections.

A fourth wave of infections that hit Israel in June began subsiding in September. But over the past two weeks the "R", or reproduction rate of the virus, that had remained below one for two months began climbing and has now crossed that threshold, indicating the virus could again be spreading exponentially.

Daily cases have also crept up over the past few days, with half the confirmed infections presently among children age 11 and younger.

Israel's 9.4 million population is relatively young, with around 1.2 million children in the 5-to-11 age group. By November, that group comprised more than a third of new cases, according to health ministry data. Scientists and officials have been doubtful the country can reach "herd immunity" unless children are vaccinated.

But policy makers also say that the vaccination of younger children is meant first and foremost to protect their individual health and not just to stop the transmission of the virus.

In the past week they have stressed that although COVID-19 is rarely severe among young children, many show no symptoms at all, it can carry risks in the longer term.

Israel's health ministry estimates that one in 3,500 children infected with coronavirus will later develop Multisystem Inflammatory Syndrome in Children (MIS-C)in which parts of the body become inflamed, including the heart, lungs, kidneys, brain, skin, and gastrointestinal organs. Most children who suffer from the condition require intensive care treatment and 1-2 per cent die.

Officials have also noted the risk of lingering symptoms, such as sleep disruption, muscle pain, loss of smell and taste, headaches and a cough, commonly known as "long COVID".

A survey by the health ministry of more than 13,000 children showed that around 11 per cent of them had suffered lingering symptoms, with 1.8 per cent to 4.6 per cent, depending on their age, six months after recovery.

"All these phenomena can be severe and we want to prevent them," Health Minister Nitzan Horowitz told lawmakers on Monday.

Monday's vaccination kicked off in a Tel Aviv square and the campaign will start nationwide on Tuesday.

A poll by Israeli healthcare provider Maccabi found that 41 per cent of parents to children age 5 to 11 were positive they will vaccinate their children, while 21 per cent were still undecided and 38 per cent will not vaccinate their children.

Israel has recorded 1.3 million total confirmed cases and more than 8,000 dead since the start of the pandemic.

Around 57 per cent of Israel's population is fully vaccinated, according to the health ministry, which means they have either received a third jab or it has not yet been five months since receiving their second.