Vaccinating Europe is a difficult mission

BarcelonaVaccinating 8 billion people against coronavirus will be the most important challenge facing humanity in 2021. A small step in this titanic task began in Europe this weekend when, symbolically, the Pfizer/BioNTech vaccine, the first to be licensed by the European Commission, will have begun to be administered simultaneously throughout the EU between yesterday and Tuesday. The operation is a major logistical challenge. The main problem will be to manage the shortage: at least in a first phase, when small groups will be selected from the priority population groups. "What we need is to vaccinate the majority, more than 70% of the world's population in the shortest possible time, and this has never been done before", Julià Blanco, a researcher at the Institut Germans Trias y Pujol and IrsiCaixa, explains. "The production of vaccines is a limiting factor because we are not talking about vaccinating only newborns. That's why the ideal is that there are different companies manufacturing and that each vaccine serves a specific group".

How should vaccination work on a global scale?

One of the main challenges is that the first vaccines to be developed use messenger RNA technology, which had been tested in humans only on a small scale, to fight diseases such as cancer and Ebola. Therefore, there is no capacity yet to produce them on an industrial scale and we already know that only with the Pfizer-BioNTech vaccine or the Moderna vaccine, which is based on the same technology, there will not be enough to contain the pandemic. In order to have production capacity on a planetary scale, we will have to wait for the authorization of vaccines based on a more classic technology that works with the viral vector, such as the Oxford vaccine, the Russian vaccine or the one implemented in China, which are in various phases of development. "Millions of doses of these vaccines are already being manufactured, waiting for authorisation. More vaccines will follow, such as Janssen's, which are already being tested in people [phase III and IV]. All of this will help us have the capacity for immunity, but we have to be clear that we have to talk about vaccines in plural and about global vaccination all over the world", Blanco warns. "If 60% or 70% of the world's population is not vaccinated, there is a risk - unlikely but not unthinkable - that the virus will continue to mutate and end up generating some variant that is resistant to the vaccines we have now". And, as if the challenge were not enough, it should not be forgotten that all other vaccines must continue to be manufactured and distributed.

Why is it important to maintain the cold chain?

RNA is a very unstable molecule, which degrades very quickly and has to be kept at very low temperatures: 70 degrees below zero for Pfizer, and 20 degrees below zero for Moderna. This multiplies the logistical challenge: ultra-freezers are needed and the cold chain must be secured at all stages of transport. "We have developed innovations in the packaging and storage of vaccines appropriate for the diversity of locations where we believe more immunity will be created", Pfizer explains. The vaccines will travel from the company's factory in the Belgian town of Puurs in these temperature-controlled containers, which use dry ice and are equipped with thermal sensors and a GPS tracking system. If not opened, the containers can maintain the temperature for ten days and each holds 4,875 doses. They will arrive in each country by air, in weekly shipments, and will be transported to warehouses equipped with deep-freezers. If not available, the containers can maintain the temperature for up to thirty days provided that the dry ice is replenished every five days.

What are the most problematic logistical points?

DHL, the distribution company - and Pfizer's strategic logistics partner -, published a study in September warning of the problems identified since the first wave of covid-19: quality controls, restricted transport capacity, customs requirements, regulations, storage difficulties and lack of transparency about stocks. DHL estimates that "ensuring global vaccine coverage for the next two years will require about 200,000 refrigerated cargo container movements on about 15,000 flights", and warns that local distribution will require "15 million refrigerated boxes and associated dry ice blocks".

"The production of dry ice does not seem to be a problem when distributing the vaccine. But even in extreme circumstances, both the availability of appropriate packaging and the maximum permitted quantities of dry ice in air cargo transport could limit shipping capacity in some cases". In addition, distributors must be trained and equipped to handle the frozen packages, and the company points out that maintaining the cold chain is much more difficult with small boxes than with large pallets.

How should it be administered?

First the vials have to be defrosted and kept in a conventional refrigerator, where they have to be kept between two and eight degrees for a maximum of five days. This is when the race begins: once thawed, the vials cannot be refrozen and, if the vaccine is not administered, it is lost after this whole journey. This requires very precise planning of the vaccination: if a thousand doses are thawed, a thousand people must be vaccinated in less than five days.

As for the injection, each vial contains five doses in a concentrated formulation. Saline must be injected into the vial to generate these five doses. The vaccine is administered with a 25-gauge needle into the shoulder. The vaccine is inoculated into the muscle mass (deltoid) because that is where the RNA will be introduced into the body's cellular tissue.

How is safety ensured?

The vaccines will be transported by Pfizer's logistics partners, which in Europe are DHL and FedEx. For "security" reasons, these companies prefer not to provide details about logistics and distribution, as the vaccines will become a precious booty for thieves. "We will see robberies, warehouse assaults and attacks on vaccine shipments", Interpol Secretary General Jürgen Stock told a German magazine this week. European sources tell the ARA that counterfeiting is less likely: "The various controls on all players in a tightly controlled supply chain ensure security". In addition, these vaccines are prescription drugs.

What about the other vaccines?

The European Commission has ordered 300 million doses of the Pfizer vaccine. According to the plan, 200 million doses will be completed by September 2021 and will serve to immunise 100 million Europeans, since the vaccine is administered in two doses. The Commission and the Member States are working to activate the additional 100 million doses. As of January 6, the European Medicines Agency (EMA) can authorize the Moderna vaccine (160 million doses), also created with messenger RNA technology. This vaccine will be easier to transport because it is kept at -20°C. The Commission has already signed contracts with AstraZeneca (400 million doses), Sanofi-GSK (300 million), Johnson & Johnson (for 400 million people) and CureVac (405 million doses).

Which groups should be prioritised?

According to Josep Maria Jansa, head of the response area at the European Centre for Disease Prevention and Control, the choice of the optimal vaccination strategy depends on the objective to be achieved: reducing mortality, preserving life years, or reducing the pressure on the health system. There are different vaccination strategies: focusing on selected groups (e.g. individuals at severe risk, key workers, vulnerable groups); vaccinating according to age groups; focusing on groups at higher risk of exposure and subsequent transmission (e.g. exposure in occupational settings, younger adults); prioritising geographical regions with high incidence; deploying the vaccine to control active outbreaks; or implementing a universal vaccination strategy. Based on these principles, the population structure of each country, its capacities, the structure and the health system, and its epidemiological situation, it is up to each government to decide on the final strategy.