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Covid-19 vaccine: Why a robust cold chain is critical

  • Published at 12:02 am October 11th, 2020
Photo: AFP

Maintaining a pre-determined constant temperature is crucial to keeping the potency of a vaccine

Face masks, social distancing, hand-washing, and lockdown are some of the effective ways to slow down the Covid-19 pandemic. Following these measures, many countries have managed to slow down its spread. In many countries, the infection and mortality rates are unfortunately still high. 

Lockdowns slow the infection rate, but it also slows economic activities of a country, eventually leading to economic recession. So maintaining lockdown and social distancing, even if governments successfully enforce them, do not always work, particularly in densely-populated poor countries.

Vaccination is another way to slow down the infection rate of a pandemic. Various research groups around the world are working hard to develop a suitable and effective vaccine to fight the Covid-19 virus. So far, there are about 240 vaccine candidates in different developmental stages, of which around 40 are in their advanced stages of testing. Scientists are optimistic about the availability of vaccines by the middle of the next year. 

However, there will be challenges in production and distribution of this particular vaccine. First, the volume and speed of vaccination required will be unique, as about 5 billion people (60% to 70% of the global population) will need to be immunized initially to develop herd immunity. 

It is still unknown whether the vaccine will have one or two doses. For a two-dose vaccine, roughly 12 billion doses will need to be produced. This is more than double compared to the existing vaccine production capacity, and will require logistic support and cold chains on a scale like never before. 

Due to the production constraint, most likely there will be limited supply of vaccines initially, which will necessitate a prioritization of its distribution within and among the countries. Most low-income countries are vulnerable with their relatively weak health systems. Many of these countries will not be able to afford the vaccine, and will be left out or will have delayed access to the vaccine. 

All citizens in all countries should be included in the immunization program to attain a global optimal; vaccine nationalism will just prolong the pandemic. The vaccination alliance COVAX is working with WHO, GAVI, and vaccine manufacturers to increase the production capacity. 

Universal vaccine access will require an intricate and robust cold chain system. Vaccines are biological products, which are temperature-sensitive and are prone to cross-contamination. Maintaining a pre-determined constant temperature from production until the time of administration is extraordinarily important to keep the potency of a vaccine. 

Any cold chain error spoils a vaccine and is discarded. Absence of robust cold chains results in loss of potency for +25% of the vaccines. The problem persists in all countries but is mostly prevalent in developing countries including Bangladesh. Unavailability of pharmaceutical refrigerators and underperformance of them are the main problems recorded in developing countries’ cold chains. 

Other problems include transportation, unavailability of proper equipment, frequent power-outages specifically in the rural areas, and a lack of trained staff. Many health care centres do not have cold chain systems, and vaccines travel a long way from urban to rural areas, and are at higher risk of losing potency.

As a vaccine is not developed yet, its administrative protocol and logistics are still not known. Most likely the Covid-19 vaccines will need to be stored at a much colder temperature than regular vaccines and hence they will not be available at local pharmacies, doctors’ chambers, or even at local health centres. 

The leading vaccines candidate of AstraZeneca, for example, will possibly require two to eight degree Celsius whereas Moderna/Pfizer’s vaccine will require sub-zero cold chain conditions. These are difficult temperatures to maintain and will require specialized freezers. 

As the Covid-19 virus spreads rapidly, the vaccine will need to be distributed and administered rapidly. Fast-track mass vaccination will need scaling up of the cold chain system across the countries, which will require coordination of government, distributors, health care workers, and other stakeholders. 

Developed countries are working on the expansion of their cold chain system. Developing countries, like Bangladesh, on the other hand, will face additional challenges in storing and handling the vaccine. The majority of their populations live in rural areas where local health centres lack a cold chain system. 

For vaccination, either people have to come to the district health care centre, or the vaccine will need to be carried to local health centres, which will possibly increase the spoilage rate. One vaccine shot will save one life, and therefore it is extremely important to keep the spoilage rate at a minimum. Unbroken robust cold chains will play a critical role to keep spoilage rate at minimum, to save millions of lives, relax social distancing, and eventually help the economies open up and recover from recession. 

Finding a suitable vaccine is important, but equally important is developing a robust cold chain while scientists are developing the vaccine, as vaccines will need to be distributed and administered rapidly at the right temperature, all over the world. Failure to do so will create inequality in vaccine distribution. As “no one is safe, until everyone is” in this pandemic, there is a high chance that excluding some countries will not be able to break the infection cycle. 

Bangladesh has one of the world’s largest pharmaceuticals and vaccine industries, and robust traditional vaccine cold chains, but is still far from adequate in size for fast-track mass vaccination. The mass scale Covid-19 vaccination will require a new fast-track approach to assess, re-engineer, and build upon the available cold chain logistics assets and system, to deliver the vaccine at scale and speed never before considered. 

Recently Brac University has partnered with the University of Birmingham, Heriot-Watt University, and BUET to evaluate the capacity and preparedness of the cold chain framework of Bangladesh for mass scale Covid-19 vaccination. 

The findings from this research will identify the best options for creating a robust cold chain system for vaccines, and inform policy-makers and other key stakeholders, including monetary financial institutions (MFIs) about the cost-effective intervention alternatives for cold chain development for mass-scale vaccination for Covid-19, which may be useful for future emergency or disasters.

Farzana Munshi, PhD, is Professor of Economics, Department of Economics and Social Sciences, School of Humanities and Social Sciences, Brac University.