"I would go one step further and say not just that the world is at risk of vaccine apartheid, the world is in vaccine apartheid."
This warning from Dr Tedros Adhanom Ghebreyesus, director-general of the World Health Organization (WHO) – made on 18 May 2021 – has gone largely unheeded.
Now, a new pressure on global vaccine supplies has emerged, as a select number of countries with access to vast numbers of the vaccine begin booster campaigns in a bid to tackle waning levels of immunity.
Since the start of the rollout some 10 months ago, the WHO has cautioned against rich countries gobbling up vaccines at the expense of poorer ones.
Despite these efforts, the numbers are stark: in high income countries, 66.2% of people have received at least one dose of a COVID vaccine. In low income countries, it is 1.9%.
Two statistics in particular paint a picture of the effect booster campaigns have on vaccine inequality:
1. In Israel, 33.96% of the population has had a COVID booster jab
2. In 93 countries, less than 33.96% of the population has had a single COVID vaccine dose
African nations in particular have been left behind in the race to immunise. Across the continent as a whole, 5.94% of the population has had a vaccine, and 3.77% is fully vaccinated.
In contrast, in the UK 71.11% of the population has had one dose, and 64.85% is fully vaccinated.
Six of the 10 countries with the lowest vaccination rates are in Africa.
Speaking earlier in September, the African Union's (AU) top health official urged rich countries to send vaccines to Africa rather than hoarding them for boosters.
John Nkengasong told a news conference he was baffled some rich countries were disregarding WHO advice to hold off from boosters until more people were fully vaccinated worldwide.
Speaking at the same conference, WHO's Africa head Matshidiso Moeti warned that leaving the continent unvaccinated heightened the risk of a new variant emerging.
"Today it's the Delta variant, tomorrow we just don't know which variant will be out there," he said.
The current approach to boosters, warns the WHO, will make existing global vaccine inequality worse.
The organisation said in a statement: "In the context of ongoing global vaccine supply constraints, administration of booster doses will exacerbate inequities by driving up demand and consuming scarce supply while priority populations in some countries, or subnational settings, have not yet received a primary vaccination series."
On 8 September, Dr Tedros called for a stop to boosters entirely.
He told a press conference: "Today, I'm calling for an extension of the moratorium [on booster shots] until at least the end of the year to enable every country to vaccinate at least 40% of its population.
"Third doses may be necessary for the most at-risk populations where there is evidence of waning immunity against severe disease and death, such as the very small group of immunocompromised people who did not respond sufficiently to their initial dose or are no longer producing antibodies.
"But for now, we do not want to see widespread use of boosters for healthy people who are fully vaccinated."
Watch: Vaccine booster programme begins as NHS starts giving third jabs
Israel, which has administered booster jabs to the highest proportion of its population, is one of 10 countries to start giving third doses.
The US Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices will meet next week to discuss booster shots, the White House said on Wednesday.
The UK started booster jabs this week, joining the likes of France, Canada and Germany in giving extra shots to the cohorts who received their vaccines first.
Data published by Public Health England this week shows that protection from vaccines declines over time, particularly among older people and those who are clinically extremely vulnerable.
After the first person in England received a third dose, health secretary Sajid Javid said: “It is brilliant to see that the first booster jabs are being rolled out today – thanks to the phenomenal efforts of the NHS who continue to work tirelessly to help us fight COVID-19 and protect the most vulnerable.
“We know vaccines save lives and, with every jab, our wall of defence across the country gets higher, with more than 112,300 lives saved and over 24 million cases prevented in England alone.
“I urge everyone who is eligible to come forward for their booster when invited, to prolong the protection that the vaccine offers those most at risk as we approach the winter months.”