Coronavirus | Delivery of COVID-19 vaccines poses a huge challenge

Most of the COVID-19 vaccines, the RNA vaccines in particular, require –70 degrees C to –80 degree C cold-chain

November 07, 2020 11:12 pm | Updated November 08, 2020 12:06 am IST

Easy to handle:  The Oxford vaccine does not require ultracold temperatures. Hence, the existing system used in the routine immunisation programme may be able to handle the vaccines.

Easy to handle: The Oxford vaccine does not require ultracold temperatures. Hence, the existing system used in the routine immunisation programme may be able to handle the vaccines.

The government recently said it will procure the vaccine and distribute it under a special COVID-19 immunisation programme to four categories of people, free-of-charge. The priority groups named are healthcare professionals including doctors, nurses and ASHA workers, a second category that includes frontline workers including police and armed forces, the third category of those aged above 50 and finally those below 50 years of age with co-morbidities.

“All of those sounds like a simple rank-ordering, but it is not. Hard choices may need to be made. For example, when there is insufficient supply to offer vaccines to all who would otherwise qualify, which group will be prioritised?” asks Dr. Gagandeep Kang, Professor of microbiology at CMC Vellore in an email to The Hindu.

Deciding whom to vaccinate first may be dictated by the characteristics of the vaccines that become initially available, such as the ones that are more effective in the younger population than in older people. “Should we then not vaccinate the elderly? Is there a bar below which vaccines should not be used in a particular group? As soon as we move beyond the big picture characterisation of initial priority groups, there are more questions for discussion than clear answers,” she says.

Ultralow temperatures

But a bigger challenge comes in the form of keeping the vaccines at ultralow temperatures during distribution. Most of the COVID-19 vaccines, the RNA vaccines in particular, that are in the advanced stage of Phase-3 trials require –70 degrees C to –80 degree C cold-chain. The Ebola vaccine, too, requires the same kind of cold storage. “This kind of storage was difficult to establish in West Africa, but was managed on the scale needed for Ebola — which is in the hundred thousand doses range,” Dr. Kang recalls. “But when we need tens and hundreds of millions of doses, I do not know how feasible that will be in the U.S. or UK, let alone in India.”

Attempts are being made to modify the vaccines and increase their stability to suit the storage conditions that already exist in many parts of the world. But they are unlikely to become available in the first-generation vaccines.

Resources needed

“In India we have never had this kind of storage requirement and building the infrastructure for ultracold storage requires considerable resources, because you need not just the freezers, but also uninterrupted power supply,” Dr. Kang says. “I think we may need to decide whether vaccines that require this form of storage should be used only in cities where such facilities can be built. It may make sense to even think about bringing people to the vaccine, instead of taking the vaccine to people in some settings.”

Hence, the decision to use a COVID-19 vaccine will need to take into consideration logistics and infrastructure needed to distribute and deliver vaccines, which goes beyond financial resources to purchase vaccines.

The Oxford vaccine does not require ultracold temperatures, and hence, the existing system used in the routine immunisation programme may be able to handle the vaccines.

The next biggest challenge might be in vaccinating people with two doses four weeks apart during the pandemic. Most of the vaccines at advanced stages of Phase-3 trial use two doses of the vaccine to achieve best results. But Dr. Kang does not foresee much problem here. “Vaccinating twice one month apart is something we know and have done for polio programmes for well over a decade. Although oral vaccines are much easier to deliver than injectable vaccines, the logistics of storage, transport and delivery are similar,” she says. “For injectable vaccines where two doses need to be given three or four weeks apart, we will need to learn from our experience with polio and measles-rubella campaigns.”

Children and adults

While the national immunisation programme is limited to vaccinating children, COVID-19 vaccination will be across age groups, including older people. It remains to be seen how well the lessons learnt from the national immunisation programme can be replicated for other age groups.

With vaccines seen as one sure way to end the pandemic if 60-70% of the population is vaccinated, the question of making the vaccines available for free gains importance. But that does not rule out the possibility of selling them when vaccines become available in plenty even while they are available for free. “Initially, I assume vaccines should be prioritised for groups as identified by the government, which might mean that all vaccines are only available in the public sector, at least when supplies are limited” she says.

Buying vaccines

There is a possibility of the government allowing companies to purchase vaccines to maintain business continuity. Probably, other groups that might be willing to pay for vaccines might also become eligible to buy vaccines. “Any vaccines being diverted at a time when supply is limited deprives priority groups, so perhaps another way to think about this, is that certain types of vaccines that are unsuitable for public programmes in India because of expense or cold chain requirements, might be opened up for purchase by companies, organisations and individuals as a premium product,” says Dr. Kang. “All this is ethically contentious, and needs discussion. There are no easy decisions or choices.”

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