Solar refrigerators keep vaccinations cold, even in places without power
BOSTON, October 31 (Thomson Reuters Foundation) – Dozens of children in a clinic in North Kivu, on the eastern border of the Democratic Republic of Congo (DRC), received a measles vaccination in May, made possible by a silent revolution in refrigeration keeps vaccines cold, even in places without reliable power.
According to the global vaccine alliance Gavi, the refrigerators, a direct solar refrigerator, an ordinary, box-like refrigerator that does not require fuel or batteries, have helped to reduce child vaccinations in the poorest provinces in the DRC by 50% for the past 50 years increase.
This has contributed to reducing child mortality in the DRC to half two years ago. More than 18 million children were vaccinated last year against a deadly measles outbreak, which has dropped dramatically in recent weeks.
Now the world wants to start a much larger vaccination system as soon as vaccines for COVID-19 become available.
Delivering millions of vaccinations in Africa, a vast continent with fragile health systems and a lack of electricity to power it will be a challenging task.
And it remains unclear whether existing refrigerators can keep the vaccines cold enough to help.
Refrigeration is essential for the distribution of vaccines.
Most vaccines require cooling between 2 and 8 degrees Celsius (35-46 degrees Fahrenheit), but nearly half of the leading candidates for the COVID-19 vaccine required will require cooling to minus 80C, researchers say.
In addition, a cold chain distribution network for COVID-19 vaccines seamlessly requires low temperatures from manufacturers to airports to remote rural villages.
Despite advances that have probably saved millions of lives in recent years by keeping vaccinations cold, most African countries still have major gaps in such networks.
“This is probably the biggest logistical challenge the world has ever faced, and it is a very big challenge for sub-Saharan Africa with a significant rural population,” said Toby Peters, a professor specializing in refrigeration systems for food and medicine at the British University of Birmingham. .
When William Clemmer, a doctor with an IMA world health, without faith care, arrived in the DRC, many health centers used kerosene-powered refrigerators, which could often break down, damage or destroy vaccines.
The first generation solar refrigerators were an improvement, but they needed storage batteries that were no longer working after two to three years and that were difficult to replace.
Solar-powered refrigerators have changed that, about ten years ago.
They cost between $ 3,500 and $ 9,000 and are connected directly to photovoltaic panels, which provide thermal energy to freeze a thick liner of water, and the ice layer keeps the vaccines cool for many days, regardless of the weather.
According to Gavi, in 2016 only 16% of the DRC’s rural health centers had refrigerators.
Today, almost 80% are equipped, many of which have solar power units. They have enabled 24,000 vaccination sessions in the nine poorest provinces over the past year, a jump of 50% from 2018.
“They have, in fact, revolutionized the delivery of vaccines to children in sub – Saharan Africa,” Clemmer said.
Karan Sagar, a doctor who heads the Gavi team for health systems and vaccinations, acknowledges the equipment that did not use the network, as it was a 25% increase a decade ago in the vaccination rates in Africa in Africa.
Since 2017, a $ 250 million effort led by Gavi has delivered more than 15,300 direct-drive refrigerators to three dozen African countries, including nearly 3,400 units to the DRC and 5,400 to Nigeria.
Sagar said that 87% of children in African countries received the first dose of vaccine for diphtheria, tetanus and pertussis (pertussis) last year.
“This is a testament to the ability of supply chains to reach even the most remote communities in the world,” he said.
FACTORY TO TOWN
It is not just ultra-cold temperatures for COVID-19 vaccines that Africa needs.
Refrigerators in the sun are only the last of the many steps needed to move the vaccines quickly and safely from centralized manufacturing sites – inside or outside Africa – to urban and rural destinations across the continent.
At every step along the way – planes, warehouses, trucks, motorcycles, bicycles, canoes and even drones – the vaccines must be kept at specific, very cold temperatures, just like other perishable products.
And significantly larger volumes are needed.
While child vaccination campaigns reach about 115 million babies worldwide each year, the COVID-19 vaccine will have to reach as many as 750 million people in Africa alone, health experts predict.
To prepare for this challenge, cold-chain expert Peters is leading an effort by the government to evaluate the needs of Africa in delivering a finite COVID-19 vaccine, along with non-profit, commercial and academic partners.
They use lessons from Rwanda, a country in Central East Africa that has made tremendous progress over the past few years in building efficient, climate-friendly refrigeration chains for food and vaccine delivery.
The system develops around one warehouse that serves as a cooling center for vaccines distributed to district hospitals, health centers and remote rural health posts, of which dozens use solar cabinets.
According to the World Health Organization, the vaccines reach more than 95% of the population.
But repeating the success of Rwanda will be a huge task. “Rwanda is small – countries like Nigeria are much more difficult,” Peters said.
Food refrigeration chains where greater commercial capacity is more established will be the kind of model needed, he added.
“We know how to move hundreds of millions of tonnes of fresh food from small farms across Africa to the refrigerators of consumers in Europe,” Peters said. “We need to take this expertise and transfer it to vaccines.”
But this is before considering the potential ultra-refrigeration needs COVID-19 vaccines require – which direct-drive refrigerators are usually not equipped to handle.
Rwanda and the DRC do have first-hand experience of vaccinations requiring ultra-cold storage in the form of a new vaccine that helped end the Ebola outbreak last summer.
‘Super thermos’ coolers, filled with blocks of synthetic alcohol ice, kept the vaccine at minus 60-80C for up to 6.5 days. But the amounts involved were a small fraction of what would be needed for an effective COVID-19 vaccine.
“Few African economies have any ultra-cold chain capacity at all,” Sagar noted.
Peters hopes COVID-19 vaccines will only require the standard cold room at 2-8C, which can provide direct-drive refrigerators at rural health centers.
“If the mainstream cooling chains are to come under it, we have a huge new challenge,” he said.