Europe's medicines regulator said Tuesday that blood clots should be listed as a "very rare" side effect of Johnson & Johnson's coronavirus vaccine, but that the benefits of the shot still outweighed the risks.

The United States is expected to announce its decision on the single-shot J&J vaccine by Friday, as nations around the world urgently try to accelerate inoculation campaigns and revive their pandemic-ravaged economies.

The looming virus lockdown of India's capital forced thousands to try and flee the restrictions
The looming virus lockdown of India's capital forced thousands to try and flee the restrictions AFP / Sajjad HUSSAIN

The European Medicines Agency (EMA) assessment came as an EU official promised to have enough doses available to vaccinate 70 percent of European adults by the summer -- a boon for the continent's sluggish rollout.

Europe's Johnson & Johnson campaign was delayed after US health regulators said the shot should be paused over blood clot fears.

After reviewing isolated cases of clotting among people who received the vaccine, EMA's safety committee said it found a "possible link" to the jab.

Map showing the number of Covid-19 active cases per 100,000 population by state in India, based on data from health authorities on April 19, 2021
Map showing the number of Covid-19 active cases per 100,000 population by state in India, based on data from health authorities on April 19, 2021 AFP / Kenan AUGEARD

The regulator said its safety committee "concluded that a warning about unusual blood clots with low blood platelets should be added to the product information" for the J&J shot.

"This is a very rare effect," EMA chief Emer Cooke told reporters. "But it also makes it very important for doctors and patients to be aware of the signs so that they can spot any concerns."

Shops, museums, libraries and swimming pools have reopened in Slovakia after a lengthy coronavirus lockdown
Shops, museums, libraries and swimming pools have reopened in Slovakia after a lengthy coronavirus lockdown AFP / VLADIMIR SIMICEK

Italy's health authorities said that in light of the EMA ruling, the vaccine should be considered "definitively safe" but the country would prioritise its use for people aged over 60.

Top US pandemic advisor Anthony Fauci expects a decision on the J&J vaccine by American regulators by Friday
Top U.S. pandemic advisor Anthony Fauci. POOL / Amr Alfiky

Only two countries had started administering the J&J shot before it was paused -- the United States and South Africa -- with more than seven million doses given out so far, according to an AFP tally.

The vaccine was praised as easier to administer and transport than some of its rivals, because it requires just one dose and can be stored at warmer temperatures.

Swedish climate activist Greta Thunberg has slammed the inequality in global vaccine distribution
Swedish climate activist Greta Thunberg has slammed the inequality in global vaccine distribution AFP / Jonathan NACKSTRAND

The EU approved the J&J shot on March 3 and started taking deliveries on April 19, but has not yet started administering it to people.

A top Johnson & Johnson executive said Tuesday he hoped for a speedy resolution to the current pause.

"We remain very confident and very hopeful that the benefit-risk profile will play out," Chief Financial Officer Joseph Wolk told CNBC.

The brutal coronavirus wave in India is putting immense pressure on health infrastructure and critical supplies such as oxygen
The brutal coronavirus wave in India is putting immense pressure on health infrastructure and critical supplies such as oxygen AFP / Manjunath Kiran

The J&J concerns follow similar reports of blood clots in a very small number of people who received the AstraZeneca shot.

The EMA also described those clots as a "very rare" side effect, stressing that the AstraZeneca jab's benefits outweigh the risks.

Europe's leaders are keen to accelerate vaccinations and expand availability after facing intense criticism over a slow rollout and with the public desperate for a return to some degree of normality.

Graveyards and crematoriums across India are struggling to cope with the surging number of deaths as the nation of 1.3 billion people battles a raging coronavirus outbreak.
Graveyards and crematoriums across India are struggling to cope with the surging number of deaths as the nation of 1.3 billion people battles a raging coronavirus outbreak. AFPTV / Archana THIYAGARAJAN

Thierry Breton, the EU's internal markets commissioner, told French newspaper Le Figaro the bloc was now set to have enough doses to cover 70 percent of its adult population by mid-July.

The Dutch government said Tuesday it would end its coronavirus curfew and allow cafes to serve outdoors during limited hours from April 28.

Elsewhere there was less reason for hope.

Moscow's mayor Sergei Sobyanin announced a drive to get elderly residents vaccinated to avoid a lockdown, acknowledging the deteriorating situation there.

And India, home to 1.3 billion people, is battling a worrying surge, with record daily case numbers overwhelming already stretched hospitals.

The capital New Delhi was locked down Monday for a week, and the government said all adults would be eligible for a vaccine from May as it tries to get a grip on the crisis.

In a televised address Tuesday, Prime Minister Narendra Modi acknowledged that this second wave had hit India "like a storm".

"It is a big challenge, but we have to -- together, with our courage and determination -- overcome it," he added.

The Delhi lockdown follows strict measures already imposed in other Indian states.

The US Centers for Disease Control on Monday advised against all travel to India, and the UK imposed restrictions on arrivals from the country.

India's crematoriums and gravediggers have been overwhelmed.

Social media and newspapers have been flooded with horrifying images of row upon row of burning pyres. At a cemetery in New Delhi, gravedigger Shamim told AFP: "At this rate, I will run out of space in three or four days."

Hard-hit Brazil meanwhile now has the leading overall death rate in the Americas and the entire southern hemisphere, according to AFP data.

With 176 deaths per 100,000 people since the beginning of the outbreak, Brazil has recently overtaken Peru with 174 per 100,000 and the US with 172 per 100,000.

Tokyo and several other areas are expected to follow suit, hoping to avoid Osaka's plight, where hospital beds for seriously ill coronavirus patients have run out.