Hotly anticipated Covid-19 vaccine will need effective global cold chain

This will give a shot in the arm to dealing with all preventable viral infections, including measles and polio

Every year in the last week of April, during World Immunisation Week, we reflect on the millions of lives saved each year as a result of one of the world’s most successful and cost-effective health interventions: immunisation. Who could have predicted (with the possible exception of Bill Gates and a handful of others) that during this year’s observance we would be living under circumstances formerly reserved for the pages of science fiction, because of a highly contagious coronavirus against which we have no immunity and no vaccine?

But here we are, doing our best to adapt to our changing circumstances and understand what this could all mean for the future of our healthcare system and economy. In the meantime, scientists around the globe are working furiously on a vaccine that will — hopefully soon — bring an end to the loss of life and economic turmoil.

While there is rightly much talk of “flattening the curve”, it is equally important to start thinking about how to capacitate the supply chain to ensure we get ahead, and stay ahead, of the next curve. Because even if a Covid-19 vaccine is produced and approved within the next 18-24 months, we’d still need to roll it out on a hitherto unprecedented scale.

There is also a real risk of spikes in the curves of other preventable diseases. One of the lesserknown impacts of the Covid-19 pandemic is its effect on existing routine vaccination programmes for diseases such as measles, mumps and polio. The global lockdown, including the closure of schools, means such programmes are in effect on hold. As World Health Organisation (WHO) director-general Dr Tedros Adhanom Ghebreyesus put it: “While the world strives to develop a new vaccine for Covid-19 at record speed, we must not risk losing the fight to protect everyone, everywhere, against vaccinepreventable diseases. These diseases will come roaring back if we do not vaccinate.”

One has only to look at the Democratic Republic of the Congo (DRC) to see how this displacement effect could play out. In an effort to contain the Ebola virus in 2018, restrictions on movement in that country caused a halt in the

DRC’s vaccination programme. The result was the worst measles outbreak ever seen, with more than 300,000 reported cases in which 6,000 children succumbed — more than double the Ebola death toll of 2,277 as reported by the WHO.

No doubt with the DRC’s experience in mind, the former head of SA’s National Institute for Communicable Diseases, Prof Shabir Madhi, raised particular concern last week about how few measles vaccinations have been given in the past month. We will — sooner rather than later — have to face the challenge of catching up with these delayed vaccinations in addition to rolling out the Covid-19 vaccine.

Ordinarily, vaccine development takes two to three years — sometimes up to 10 years. With the biggest brains and billions of dollars focused on Covid-19, there is some hope that a vaccine could be developed in as little as 12-18 months. And if the Covid-19 vaccine is the key to getting ahead of the virus and bringing the pandemic under control, one of our primary goals in the next 12 months must be to ensure we fully capacitate and empower all role players along the supply chain.

In our work across 74 countries, spanning five continents and supporting several nongovernmental organisations and governments with established vaccination programmes, it has become apparent that central to effective immunisation is a well-capacitated and effectively managed cold chain. Otherwise, the practical deficiencies in basic temperature control risk upending efforts to prevent the spread of Covid-19 and other diseases. What does this entail?

COLD-STORAGE DEPOTS

The cold chain is described by the WHO as “a system of storing and transporting vaccines at recommended temperatures from the point of manufacture to the point of use”. If the cold chain is broken at any point along its journey from the manufacturer to the end-user, the potency of a vaccine may be compromised. In the worst case, mainly as a result of accidental freezing, it may be rendered entirely ineffective.

We first need enough fridges and freezers to store the enormous volumes of vaccines that will need to be produced for the global population. This includes large cold-storage facilities at the national and regional distribution depots, in the refrigerated containers and temperaturecontrolled vehicles that carry the vaccines, at the hospitals and clinics that store and dispense them and, in many cases, the cooler boxes that carry the vaccines into remote villages and schools.

Unfortunately, there are many impediments to ensuring a well-maintained cold chain. Medicalgrade refrigerators are not cheap, and funding is already being stretched to near breaking point. Even when there is funding available, too often the procurement processes to acquire them are long and cumbersome. So, the government and healthcare organisations are being required to make the absolute most of the assets they have.

It is worth noting that the same fridges that carry and store vaccines often also store insulin, which is also temperature sensitive. The relevance of this cannot be overstated as underlying health conditions such as diabetes are intrinsically linked to the Covid-19 mortality rate.

The internet of things and solutions such as remote temperature monitoring and control devices monitor the cold chain in real time and ensure the proper functioning of equipment from the point of manufacture to the end-user, preserving the efficacy of these life-saving vaccines.

Global organisations such as Unicef, the International Committee of the Red Cross and the Pan American Health Organisation have already adopted the technology. Philanthropic institutions such as the Bill & Melinda Gates Foundation, the Clinton Health Access Initiative and the Gavi alliance do an incredible job of bridging the gap between the limited resources of developing countries and the high costs involved in coldchain management. But these institutions are no substitute for effective national planning and preparedness.

As the world enters a new phased approach to lifting the lockdown and more businesses begin to re-emerge, so too will governments have to enter a new phase that broadens their focus from simply containing the virus and flattening the curve to building systems to get ahead of this curve — and the others that will inevitably come.

When Covid-19 arrived, it exposed the unpreparedness of the global health-care system. Clear, efficient cold-chain and temperature management will give global public health responses the shot in the arm so critically needed to deal with preventable viral infections.