Supplies of a shingles vaccine are still facing a delay just weeks after the UK launched its national vaccination programme.
A vaccine update from Public Health England (PHE) said there were likely to be periods when there was no stock at all of the Zostavax vaccine.
Normal supply is not expected until late November or December. Until then, GPs are being restricted on the amount of vaccine they can order.
PHE said it was working closely with the manufacturer, Sanofi Pasteur MSD, to restore supplies as quickly as possible following the delay, which is due to testing the vaccine.
Until then “a restriction on the quantity of vaccine that can be ordered will remain in place while the vaccine is in stock,” the update said.
“It is likely that there will be periods of no stock.”
The NHS vaccination programme, which started last month, targets people in their 70s.
Overseen by Public Health England, it aims to protect older people across the UK who are at greatest risk from the infection.
The programme in its first year is focused on those aged 70 and 79. A phased catch-up programme for those aged 71 to 79 is already being staggered.
It is estimated 800,000 people will be eligible for the vaccine in the first year.
PHE said a large quantity of Zostavax vaccine has already been distributed throughout the UK to start the programme.
A statement said: “Currently PHE is subject to a temporary delay with the supply of the shingles vaccine, Zostavax, into the UK.
“The disruption to supply will continue until normal supplies are restored by the manufacturer, Sanofi Pasteur MSD, likely to be later in November or December.
“Vaccines are subject to lengthy rigorous testing before they are passed for supply to the UK. This testing has taken longer than anticipated, causing vaccine deliveries to be temporarily delayed.
“Such delays are unusual but not unknown.
“National distribution of the Zostavax began on August 1, based on assurances of continuity of supply from SPMSD.
“A significant volume of Zostavax has already been distributed throughout the NHS in England, allowing many clinics to go ahead as planned.”
Bruce Taylor, head of vaccines and countermeasures response at PHE, said: “Although we are disappointed with the delay of the shingles vaccine arriving in the UK as planned, PHE is working with the manufacturer to agree remedial action and resume supplies as quickly as possible.
“A large quantity of vaccine has already been distributed across the UK to start the programme which began on September 1.
“We do not expect this temporary delay to impact the overall programme to immunise 70 and 79-year-olds.
“The vaccine can be administered to the two eligible cohorts at any time between September 1 2013 and August 31 2014.”
Shingles is caused by the herpes varicella-zoster virus, which also causes chickenpox.
It usually affects a specific area on either the left or right side of the body and causes a painful rash which develops into itchy blisters.
Most people feel unwell for several days before the rash appears, which can take two to four weeks to heal.
Complications can include severe nerve pain (neuralgia) that carries on after the rash and other symptoms of shingles have gone.
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