Johnson's target for virus tests already being pushed back

Johnson told Parliament on March 18 he had set a target of 25,000 tests a day, which the Health Department said would be achieved within four weeks. But progress has been complicated by supply chain issues and global competition for vital chemicals, the government says, and the 25,000-a-day goal is now unlikely to be reached until the end of the month, according to a person familiar with the matter.

In addition to the public health implications of not being able to accurately track the spread of the disease, there's considerable political risk for Johnson from any further delays after he personally took responsibility for ramping up testing rates this week. Several major newspapers used Thursday's front pages to criticize the government's handling of the crisis.

Much of the focus has been on why the U.K. lags behind neighboring countries, in particular Germany, which conducts more than 50,000 tests a day. The U.K. currently has the capacity to process 12,750 daily, but has yet to fully utilize it.

Johnson's spokesman, James Slack, told reporters 10,412 tests were carried out on Tuesday, the latest data available, and accepted the U.K. hasn't been doing enough.

But according to two people familiar with the matter, comparing the two countries is unrealistic given the comparative advantage Germany has in pharmaceutical production and biotechnology. The country's federalized health system also means it has more laboratories and has more established capacity than the U.K. for manufacturing both ventilators and testing kits, one of the people said.

According to the most recent data from the World Health Organization, Germany also outspends the U.K. on health care by more than $750 per person, and has almost three times as many acute care beds per capita.

U.K. Health Minister Nadine Dorries pushed back on the Germany comparison in a series of tweets on Thursday.

"The answer could be that Germany has a number of small, niche life science companies/labs which source and assemble the complex group of chemical reagents used in the antibody tests," she wrote. Dorries also appeared to criticize the media's focus on testing, saying "it won't cut the number of deaths, it won't make people feel better or stop them catching coronavirus."

Yet in a video message late Wednesday, Johnson appeared to acknowledge the severity of the issue -- as well as the political reality that unfavorable comparisons with other nations are unlikely to go away unless capacity is increased.

He promised to "massively ramp-up" testing, which he described as "the way through" and "how we unlock the coronavirus puzzle."

The lack of testing capacity is having an immediate impact on the state-run National Health Service's capacity to cope with the outbreak because front-line workers with symptoms -- or living in households with other people showing them -- are self-isolating to avoid the risk of infecting their patients.

More than 2,800 tests on front-line NHS staff have been completed at drive-in test sites, Slack said on Thursday, and a "significant" number in hospital and Public Health England laboratories. There are about 1.3 million employees in the NHS.

The government is working with private companies, universities and other laboratories to boost capacity, Slack said.

Johnson, who Slack said continues to show mild symptoms of the Covid-19 virus, is also under fire over the decision to halt widespread testing in March. Instead, the government chose to limit tests to patients who were taken to hospital showing likely symptoms.

Health officials and some of his advisers have since indicated the decision was based on a lack of capacity as the disease spread in greater numbers.

But the policy also reflected the pursuit of so-called herd immunity, which Chief Scientific Adviser Patrick Vallance said at the time would need 60% of the U.K. population to catch the disease to work.

The strategy was abandoned when scientific modeling made clear the NHS didn't have enough critical care beds to cope with the outbreak. The government has since said it now sees widespread testing as the key to getting through the pandemic, including ending a nationwide lockdown.

"This is how we will defeat it in the end," Johnson said.