UK delays second dose of Covid-19 vaccine while Europe considers how to speed up vaccination

The problem: Although scientists say a single dose may confer enough immunity to stop the spread of the virus, there is not enough data to confirm it, as clinical trials of available vaccines and those that were close to authorizations were designed around a two-dose regimen. .

Britain, which is under strong tension amid the spread of a new, more infectious variant of the virus, is the first European government to change its policy. He stressed that vaccine recipients would still get a second dose, just three months later than expected.

Some Canadian provinces have delayed the second dose to inoculate more people at once and Belgium is proposing a similar approach.

“The priority should be to give so many people in at-risk groups their first dose, rather than providing the necessary doses in the shortest possible time,” a spokesman for the British health department said.

A vaccine made by Pfizer Inc.

and BioNTech SE was the first authorized in the West. It is now unfolding globally following the emergency clearances of several regulators on the basis of a months-long test success that meant giving two shots to more than 20,000 volunteers. The second injection was given 21 days after the first.

Although trial data show that the vaccine conferred immunity to more than 50% of participants after the first dose, the marketing of a single shot would require a new study in which only one dose would be administered to another. group of volunteers, said Uğur, executive director of BioNTech. Shahin.

“It could be that the next generation of the vaccine will consist of just one dose,” Dr. Sahin said.

He added that bottlenecks in production meant that vaccines would not tangibly slow the spread of the virus for months, meaning social restrictions would have to be subtracted.

“We need other vaccine producers to get market approval next year, ideally during the first quarter … We just need more companies to supply more doses,” Dr. Sahin said.

A vaccine developed by Moderna Inc.,

which was authorized in the US and which the European Union regulator could give the green light to in January, also consists of two doses. A third vaccine, developed by Oxford University and AstraZeneca PLC and authorized on Wednesday in the UK, has two similar doses.

Proponents of a single-dose approach say this could be the only way to vaccinate enough people to prevent another rise in infections next winter, due to limited availability.

EU governments have only bought enough Pfizer-BioNTech vaccines to inoculate 150 million people out of a total population of about 450 million. This quota will not be fully delivered until the end of next year.

Most scientists agree that more than 60% of the population should be vaccinated to achieve herd immunity, in which there are enough people immunized, either by vaccination or contracting the disease, to stop the spread of a disease. pathogen.

In Belgium, Health Minister Frank Vandenbroucke has called on the country’s vaccine working group to consider whether to postpone the administration of the second shot, in order to give the first dose to more people more quickly. .

Pierre Van Damme, a senior member of the working group, said on Monday that using just one shot would allow most of Belgium’s 11.5 million people to be vaccinated before the summer. A government spokesman said a decision would be made in the next two weeks.

In Britain, Professor David Salisbury, a former head of the country’s vaccination program, had been campaigning to delay the second shot until all high-risk people had had the first dose. After two weeks of declining infections, new cases have risen sharply in the UK since early December.

On December 22, former UK Prime Minister Tony Blair told the Independent newspaper that proceeding with the planned second shot schedule would cause “colossal” damage in terms of infection rates, deaths and economic impact.

Write to Bojan Pancevski to [email protected]