(AFP) - The Pfizer Covid-19 vaccine proved 94 percent effective in a huge real world study published Wednesday that involved 1.2 million people in Israel, confirming the power of mass immunization campaigns to end the coronavirus pandemic.

The good news came as Ghana became the first country to receive shots under the global Covax scheme, paving the way for poorer nations to catch up with wealthier parts of the world.

The Israeli study, published in the New England Journal of Medicine, also demonstrated there is likely a strong protective benefit against infection, a crucial element in breaking onward transmission.

"This is the first peer-reviewed large scale evidence for the effectiveness of a vaccine in real world conditions," Ben Reis, a researcher at Harvard Medical School and one of the paper's authors, told AFP.

It involved almost 600,000 people who received the shots and an equal number who hadn't but were closely matched to their vaccinated counterparts by age, sex, geographic, medical and other characteristics.

The efficacy against symptomatic Covid-19 was 94 percent seven or more days after the second dose -- very close to the 95 percent achieved during Phase 3 clinical trials.

More than 217 million vaccine doses have been administered globally, according to an AFP tally Wednesday, though the vast majority have been given in high-income countries.

Hopes are high that the inoculations will allow the world to finally emerge from a pandemic that has killed more than 2.4 million, infected 112 million, and hammered the global economy.

But health experts have warned that unless the whole world has access to vaccines, the pandemic will not end.

The head of the World Health Organization applauded the first delivery of the Covax vaccines Wednesday.

"At last!" WHO chief Tedros Adhanom Ghebreyesus said in a tweet.

The WHO is one of several organizations behind Covax, which aims to deliver at least two billion doses globally by the end of the year.

The 600,000 doses delivered to Ghana in a ceremony broadcast live on television are from Oxford-AstraZeneca, and will be administered in several Ghanaian cities from Tuesday.

They are part of an initial tranche of deliveries bound for several low- and middle-income countries, including to Ivory Coast this week.

Covax, led by Gavi the Vaccine Alliance, the WHO and the Coalition for Epidemic Preparedness Innovations (CEPI), is seeking to ensure vaccines are equitably distributed globally.

In South Africa, struggling with a recession as well as the pandemic, Finance Minister Tito Mboweni said the government planned to allocate 10 billion rand ($688 million) to buy and deliver coronavirus vaccines over the next two years.

- Single-shot vaccine -

More upbeat data meanwhile emerged about Johnson & Johnson's single-shot vaccine, which was shown to be highly effective against severe Covid-19, including newer variants, in detailed data released by the US regulator.

The vaccine is likely to be authorized soon, making it the third available in the hardest-hit country.

US biotech firm Moderna also announced its new Covid vaccine candidate aimed at the dangerous South African coronavirus variant had been shipped to government labs for testing.

But Europe's vaccine rollout faced fresh problems after AstraZeneca said it would only be able to deliver half its promised doses to the EU, deepening tensions with the bloc over supply shortfalls.

It is the latest setback for the bloc, which has come under fire for its sluggish vaccine rollout.

EU chief Ursula von der Leyen was locked in a war of words with AstraZeneca earlier this year after accusing the British-Swedish firm of breaking a contract by delaying vaccine deliveries.

But she struck a more affable tone Wednesday, saying she was "optimistic" about the rollout.

"New questions are always arising that we can generally resolve amicably," she told a German newspaper.

- Six Nations match on-

Elsewhere on the continent, Hungary forged ahead with its own campaign, administering Chinese-made Sinopharm jabs in a first for the EU, having already become the first EU nation to administer Russia's Sputnik V vaccine.

Ukraine also celebrated a landmark Wednesday, giving a doctor the country's first Covid shot, a slow start to its own vaccination programme that has sparked widespread anger there.

In Israel, parliament passed a law allowing the government to share the identities of people not vaccinated against the coronavirus with other authorities, raising privacy concerns for those opting out of inoculation.

In sports, a Six Nations rugby match between France and Scotland will go ahead in Paris this weekend as planned despite an outbreak of coronavirus cases in the home camp involving 15 players and staff.

© Agence France-Presse