Europe Faces Wait for Vaccination

The U.K., a non-EU country, became the first Western country to launch its vaccination program, rolling out the Pfizer shot on Dec. 8 at dozens of hospitals around the country. Next week, the U.K. plans to extend the program to involve local physicians.

EU countries must wait at least another month. The bloc’s drug regulator, the European Medicines Agency, is set to give its opinion on the Pfizer vaccine on Dec. 29 and on Moderna’s on Jan. 12. Many EU countries are planning to start administering the Pfizer vaccine in January, starting with elderly people, health-care workers and other high-priority groups.

Most European countries haven’t laid out concrete timetables for vaccinating their populations, amid uncertainty over how many doses of approved vaccines will be available when.

The EU’s 27 member countries agreed to let their common executive, the European Commission, buy vaccines centrally, and allocate them to countries according to their population size. The commission says it has preordered nearly two billion vaccine doses from six suppliers, including up to 300 million from Pfizer and as many as 160 million from Moderna. Those two vaccines, like most of the others, require two doses per person, meaning that the orders placed so far would cover only about half of the EU population.

Meeting those orders quickly will be difficult. Both vaccines use new gene-based technology, named mRNA, that injects viral RNA into the body’s cells, but it is tricky to scale up. In Switzerland, a contractor for Moderna is still honing a process that involves threading strands of viral genetic material into nano-sized fat particles without allowing oxygen to seep in or fluctuating temperatures to compromise the vaccine’s stability.

The other vaccine candidates face lengthy holdups. The EU’s plan relied heavily on a shot developed by AstraZeneca PLC and the University of Oxford. But that vaccine was met with skepticism from regulators after test subjects were given inconsistent doses during clinical trials. Further study and scrutiny is expected to take months.

EU countries were also looking to Sanofi SA and GlaxoSmithKline PLC to meet a large portion of their needs. But the drugmakers said on Friday that their candidate didn’t provoke a strong immune response in the older age groups that need the vaccine most, and that a revised version of the shot wouldn’t be ready until the end of 2021.

Another vaccine candidate using mRNA technology, by German-Dutch pharmaceutical company CureVac, is further behind and hasn’t yet begun large-scale clinical trials.

The upshot is that, while most EU countries expect to begin vaccinations in January, none know exactly when they will be able to vaccinate enough of their populations to allow everyday life to return to normal. Because young, fit people—who tend to be the biggest spreaders of the virus—are last in line for a jab, transmission could carry on for much of 2021. Europe’s hope is to at least relieve the pressure on health-care systems by inoculating enough of the elderly and vulnerable to reduce the numbers of severely ill.

“There are problems not just with the procurement of vaccines. We don’t know how long their efficacy will last,” said Deepti Gurdasani, a clinical epidemiologist and senior lecturer at the Queen Mary University of London. The history of vaccinations shows diseases are rarely eliminated quickly, he said. “This idea that Covid will end by summer or by the end of next year, it’s frankly ridiculous.”

The U.K.’s rollout plan shows the logistical challenges of mass vaccination against Covid-19–especially when, like the Pfizer shot, doses must be stored at super-cold temperatures and administered quickly once thawed.

British authorities plan to start delivering 975-dose packs of the Pfizer vaccine to local family physicians on Tuesday. Doctors will have limited time to administer the doses; they can last five days once thawed and stored in a refrigerator. Some U.K. doctors have warned that it will be difficult to organize and monitor vaccine recipients quickly with limited staff and resources without some of the doses going to waste.

U.K. Health Secretary Matt Hancock said on Thursday he hoped to start administering vaccinations in care homes by Christmas. “As more vaccines come on stream, we’ll open more centers in larger venues like sports stadia, conference halls next year, and that’s when most people can expect to get their jabs,” he said.

“When enough people get vaccinated and we see those hospitalization numbers coming down, we can then start lifting those restrictions which have made this year so tough,” Mr. Hancock said.

But U.K. authorities remain worried about the next three months or so, as the promise of a vaccine and Christmas mingling prompt people to relax their behavior.

In Germany, the 16 autonomous states will handle the vaccine rollout, leading to a mosaic of different approaches and varying degrees of efficiency. The wealthy southern state of Bavaria, which boasts one of the most efficient public administrations, said it expected to start vaccinations on Jan.5. In Germany as elsewhere in Europe, the first in line will include elderly people, front-line health-care workers, and staff in care homes.

Germany’s Health Ministry estimates that roughly 60% of the country’s 83 million inhabitants would need to be vaccinated to achieve so-called herd immunity. There is no estimate as to when that could happen. The ministry reckons it might take seven months before vaccination reaches beyond high-priority groups to the general population. But that projection assumes several companies will be marketing vaccines soon.

In practice, at most five million people in Germany are likely to be vaccinated by late March, said Karl Lauterbach, a German epidemiologist and legislator for the Social Democratic Party.

France plans to vaccinate a million people from January to mid-February, beginning with nursing homes and their staff, and reach 14 million more people by the end of March, prioritizing the elderly, vulnerable groups and medical staff. From spring onward, the vaccination program would broaden, but with no specific timetable at present.

The Netherlands and Belgium aim to vaccinate 70% of their populations, but neither has set a deadline. “Some politicians have been too optimistic,” said Herman Goosens, a microbiologist at the University of Antwerp, who met Friday to advise the Belgian government. “It will not be done by the summer.”

Italy expects to receive its first consignments of vaccine at the end of January. It will start by vaccinating some 1.4 million doctors and other health workers, followed by the residents and staff of care homes, or some 570,000 people. The next groups will be 4.4 million Italians over age 80, 13.4 million aged 60-79, and 7.4 million people with chronic diseases that make them vulnerable to Covid-19. The large portion of elderly people in Italy’s 60 million population has contributed to a particularly high death toll in the pandemic.

—Giovanni Legorano and Bojan Pancevski contributed to this article.

Write to Drew Hinshaw at drew.hinshaw@wsj.com and Joanna Sugden at joanna.sugden@wsj.com