After months of development and clinical trials involving tens of thousands of volunteers, countries have begun vaccinating their populations.
While the approval of several Covid-19 vaccines in less than a year is a scientific achievement to be celebrated, concerns are rising over "vaccine nationalism".
Prompting these concerns are the way that some countries were first in line to inoculate their populations because they funded vaccine development.
A reported 9.6 billion doses have already been bought or reserved, potentially shutting out nations that lacked the financial muscle to invest in projects early in the pandemic.
“The rich countries have bought up a lot of the initial supplies of the first vaccines,” said Dr Andrew Freedman, an infectious diseases specialist in Cardiff University’s School of Medicine in the UK.
“The pharma companies have committed to ensuring they are available to developing countries as well, but it’s not just the availability of the vaccines, it’s the infrastructure to deliver them.”
Prof David Salisbury, former chairperson of the World Health Organisation’s Strategic Advisory Group of Experts on Immunisation and a former director of immunisation at the UK Department of Health, suggested the signs so far were not promising.
“[Developing countries] totally depend on what manufacturers can provide for them,” he said.
"So far it doesn’t seem as if quantities of vaccine being provided are ahead of what was promised.
"If anything, they are behind."
As countries look to immunise their populations as quickly as possible, several vaccines are available now or will be soon.
These include the Pfizer-BioNTech vaccine – a US-German medicine – the Moderna vaccine from the US, Russia’s Sputnik V, the Oxford-AstraZeneca vaccine from the UK and vaccines from China’s Sinopharm and other Chinese pharmaceutical companies.
A Chinese official quoted by media has said 600m doses of coronavirus vaccine would be “ready” by the end of 2020 without specifying what this meant in terms of immunisation.
Meanwhile, Russia – which begin vaccinations using Sputnik V in Moscow in early December – recently announced agreements for the production of its vaccines at eight sites “in several countries”.
Many developing countries will have manufacturing facilities for Western-developed vaccines too.
India, a global pharmaceutical manufacturing powerhouse, is set to produce billions of doses of vaccines developed locally, in the West and elsewhere.
These will be distributed at home and abroad – especially to low and middle-income countries.
In November, the University of Oxford said the vaccine it was providing with AstraZeneca was being manufactured in more than 10 nations to ensure “equitable” global access.
Some developing countries, such as Brazil, which has been especially hard by the pandemic, with more than 190,000 deaths, have forged links with the programme by holding clinical trials.
In August, president Jair Bolsonaro announced a $356m (Dh1.31bn) agreement to purchase and produce 100m doses of the vaccine. Much more could follow next year, along with tens of millions of doses of the Pfizer-BioNTech vaccine, which Mexico too has secured supplies of.
Meanwhile, there are initiatives in Brazil to produce a Chinese vaccine, Sinovac’s CoronaVac, which numerous other Latin American countries have also shown an interest in. CoronaVac is also being distributed in Turkey, where successful clinical trials were held.
As well as deals forged by individual nations, Covax – an initiative from the World Health Organisation, the Global Alliance for Vaccines and Immunisation (Gavi) and the Coalition for Epidemic Preparedness Innovations (Cepi) – will be central to achieving widespread distribution, especially in low-income countries.
Brazil is set to receive tens of millions of doses through the programme, which involves 190 countries.
About half the members, among them the UAE, are self-financing and, along with philanthropic organisations like and Bill & Melinda Gates Foundation, the private sector and the European Commission, will subsidise supplies to Covax’s poorer nations.
In mid-December, Covax announced it had secured access to two billion doses of various vaccines, and all participating countries are due to receive doses for their most vulnerable groups in the first half of 2021.
Agreements cover, for example, 200m doses of a vaccine from the Serum Institute of India, 170m of the Oxford-AstraZeneca vaccine and 500m of a Johnson & Johnson-Janssen vaccine set for approval soon.
Covax has raised $2bn so far, but $5bn is needed for procurement and distribution next year, so the programme’s effectiveness and the extent to which poorer nations can begin vaccinating depends on the generosity of better-off countries.
Practical issues could delay programmes in some of the least wealthy countries, as their infrastructure for vaccine delivery is less advanced.
The Pfizer-BioNTech vaccine, which has to be kept at between -70°C and -80°C, may be difficult to distribute, although storage with dry ice in insulated boxes will reduce the need for expensive cold-storage equipment.
Developing countries lacking annual influenza vaccination programmes, which typically focus on the elderly, may find it harder to identify their most at-risk individuals.
However, a factor that could help poorer countries is the way that leading vaccines have proved so effective in clinical trials, suggested Prof Paul Hunter, an infectious diseases specialist at the University of East Anglia in the UK.
Developed nations, which have spread their risk by purchasing doses of multiple vaccines based on different types of technology, may not require all the supplies they purchased, so it could be that “there’s a lot of vaccine going really cheap”.
“I’ve not heard anybody say that, but it did strike me as a possible silver lining,” he said.
The UK, for example, has bought or has options on more than 400m doses of seven types of vaccine, many more than needed for a 66m population, especially as some groups such as children may not require vaccination.
It remains to be seen how well the various vaccines will prevent transmission as well as illness. If they are ineffective at stopping spread, there will be reduced benefit in vaccinating younger adults, who are less vulnerable. This too could result in greater global availability.
Demographics too could ease the effect of shortages: developing nations tend to have younger populations, so the proportion of citizens vulnerable to the coronavirus is lower.
“They’re not getting anywhere near the mortality rates we’re seeing in Europe and North America. There are a lot fewer people over 55 in Africa compared to Europe. The death rates in these countries probably won’t be as dramatic as here,” said Prof Hunter.
Indeed, per capita death rates paint a stark picture: eight of the 10 worst-affected nations are in Europe, with the hardest-hit African country, South Africa, only the 37th-worst-affected globally.
Ultimately, immunising the most vulnerable people in just developed nations is likely to take most of 2021, according to Dr Freedman.
“It may take considerably longer than that to roll it out to developing countries. A year is optimistic. Programmes will start, but to deliver it to every adult, that will take a lot longer,” he said.
Some experts have suggested it could be well into 2022 before some people in developing nations receive their vaccinations.
Despite the complications of supply and distribution, globally there is widespread acknowledgement that coronavirus vaccination programmes must take place as widely as possible.
“With Covid, everybody knows if you vaccinate one country, you won’t be safe. The whole world needs to be vaccinated,” said Prof Polly Roy, professor of virology at the London School of Hygiene and Tropical Medicine.
“I think there will definitely be a way forward: the vaccine-[creating] countries, as well as the different foundations delivering the vaccine, will insist everybody needs the vaccine.”