KEY health staff are being vaccinated against the swine flu virus as doctors warn infection rates could get “substantially” worse.

Health bosses confirmed second wave of the virus had hit and said analysis showed about 60-70 people a day are reporting symptoms across the borough.

At its peak earlier in the year, about 230 people a day were requiring treatment for swine flu, and although well down on those numbers, health services are bracing themselves for a potential surge as the weather gets colder.

The current phase of the vaccination programme involves many nurses and care workers receiving their jabs first.

Dr Andrew Burnett, director of health improvement and medical director at NHS Barnet, said immunisation is the most effective form of protection and claimed people have been “enthusiastic” about receiving it.

He said: “Front line staff need to be immunised because they are more at risk of getting swine flu. If they get infected there is a risk they will infect patients, many of who may be vulnerable.”

Following the hight of the spring and summer infection rates, numbers leveled out at about 20 a day, until beginning to rise again to the current levels.

And Dr Burnett said a 30 per cent “attack rate” would see 100,000 people infected across the borough throughout the winter.

He said: “Seasonal flu tends to get worse when its colder and tends to hit people more in December, January and February.

“There is no reason to suppose swine flu wont behave in a very similar way it's just a different virus.

“It could get worse, the numbers could go up substantially, but if we have a lull now it is important people take advantage of the immunisation available.”