Each morning, four giant lorries arrive at the loading docks at Seqirus’s vaccine plant in Liverpool like clockwork. On board, a precious cargo — 575,000 chicken eggs in which lie the seasonal safety of the nation.
This daily delivery is the crucial first step in creating the flu vaccine that will protect the public and stop the NHS being overwhelmed by influenza and Covid-19 — and the Mail is the first to see the inside of the factory at the centre of it all.
This winter could be the most severe flu season in recent history. There are up to 60,000 deaths due to reduced flu immunity. A potential Covid third-wave could also derail an already fragile health system.
Professor Jonathan Van-Tam, England’s Deputy Chief Med Officer, warned this week about the dangers of flu. Flu will be circulating with Covid-19, and people are more likely to mix indoors in cold weather.
The eggs are washed, separated and incubated in 37 rooms. Each room contains 172,000 fertilised eggs. To ensure that a virus can reproduce, they are kept under strict control for 11 days. The eggs are stored on racks that change their angle of tilt every hour and stay at a precise temperature of 37.5c (99.5f) and 65 per cent humidity — the ideal conditions to develop their embryos
The eggs are then ready for the production line, which scans 132 eggs at a time and rejects those that are infertile — 45,000 a day — before being jabbed with a needle with 0.2 ml of ‘working seed’, a solution that contains the active flu virus, which has been cultured in laboratories. After this, the influenza viruses begins to multiply in the shell.
The eggs are checked for imperfections throughout the process. Experts use ultraviolet probes to examine the eggs randomly. Infertile eggs can be discarded as soon as they are found.
After 72 hours incubation, eggs are ‘blast frozen’ to stop embryo growth. The virus-infected eggs join a harvesting line. Here, a large machine uses a blade for cutting off the eggshells. Probes extract some of the clear liquid from inside the egg, known as allantoic fluid — which now contains thousands of copies of the influenza virus
Salvation arrives in small syringes containing 0.5ml of vaccine. The syringe begins its journey to the patient at an 18,-acre plant in a hinterland that includes warehouses and factories in south Liverpool.
It produces 6.1 million eggs at peak production. There are 650 employees who work around the clock to combat flu.
Fertilized chicken eggs can be used to cultivate the essential components of an effective vaccine.
They have refined production at the Seqirus facility to the point that it will despatch as many as 30 million doses each year to immunise Britain.
All over-65s can receive egg-based vaccines because they can carry the adjuvant which promotes an immune response. Vegans can request cell-generated jabs.
Alan Collins, the primary incubation unit leader, said, “The scale is amazing.”
‘Every component of the process must work together to ensure that we have enough vaccine to keep the nation protected. It is a difficult and time-consuming production line, but I enjoy coming in to work every day because I am helping to protect lives.
Seqirus has recently invested £50 million in production facilities and taken on 120 new staff.
The virus is then activated using formaldehyde. Finally, the solution is purified by centrifuging. The virus antigen remains in the solution. This activates the immune response of the human body to the infection, without causing illness. Seqirus creates four strains, which were identified by the World Health Organisation (February) and then mixes them to create a quadrivalent vaccine (above), to protect patients from the four flu strains.
The entire vaccine solution is stored in huge 500-litre sacks. The sterile machine then fills the syringes at high speed
Before the workers at the production plant thoroughly inspect the batches of vaccines, the solution is measured and placed in 0.5 ml Syringes.
The final product will be distributed to pharmacists and doctors across the country.
John Riley, a leader in the formulation process, stated that quality control is a top priority at all stages.
“Every 500-litre batch that we produce contains 900,000. 900,000. 900,000. This is 900,000. We are protecting the lives of 900,000. And we don’t want any problems.”
Raja Rajaram is the head of medical affairs at Seqirus. He adds that this is an important flu season. The uptake of the vaccine is critical to ensure the NHS is not overloaded this winter.
‘We had virtually no flu last year — but now we have been released from the lockdowns, we are mixing more freely with people going back to offices and starting to travel. The vaccine will play a significant role in reducing the NHS’s burden.
You can also give the flu vaccine together with a Covid booster Jab.
Public Health England hopes to surpass the 80.9 per cent coverage rate of the over 65s from last winter and reach 85 per cent this season in the UK’s largest ever flu vaccine program.
The jab can also be offered to over-50s and younger children.
Millions will receive their injections this month when the flu season starts — but many will not know that the flu jab programme owes its success to the humble egg.