Newly identified variants of the virus that causes COVID-19 are on a rampage in Britain and other parts of the world.

In Japan, more than 20 cases of the British variant of the virus have been confirmed to date, found mainly in travelers who tested positive at airports. The variant found in South Africa and a new strain different from these two variants have also been discovered.

The variant first found in Britain is said to be more contagious than previously identified ones and have the potential to increase the COVID-19 reproduction number by more than 0.4. The reproduction number represents the number of new infections estimated to stem from a single case.

Many questions have yet to be answered about these new variants, such as whether the COVID-19 vaccines that have been developed so far will work against them or whether they could cause illness more frequently or more severe symptoms.

Some experts have pointed out the possibility that the South African variant may also spread more easily and quickly. But no detailed scientific information about it is available.

Since autumn, the government has been gradually reopening Japan’s borders to other countries. In response to the spread of new variants, however, the government has banned travel from most other nations, except for business travelers from 11 countries and areas where infections are not increasing sharply.

It has also decided to take stricter quarantine measures for Japanese nationals returning from abroad.

It is, of course, important to tighten border controls. But the government needs to understand that there are limits to the effectiveness of these measures. There is no denying the possibility that new variants are already spreading in Japan. The government should step up its efforts to be prepared for a major outbreak of new variants.

Japan is currently grappling with a third wave of COVID-19 infections. The government has declared a second state of emergency. If new variants spread widely under the current circumstances, the situation could get far more serious.

It is urgent to enhance the systems for real-time monitoring and information gathering. It is also crucial to accelerate the process of evaluating the risks posed by new variants by using scientific knowledge about their transmissibility and pathogenicity.

The National Institute of Infectious Diseases and prefectural institutes of public health, which play the leading roles in virus surveillance, have been engaged in genomic analyses of samples of SARS-CoV-2 virus collected in various parts of the nation.

They conducted genomic analyses of more than 14,000 samples during the nearly one year to the end of December.

Samples taken from all people who have tested positive at airports are subjected to genomic analyses, in principle.

Still, the figure represents less than 10 percent of all the cases confirmed in Japan so far. The level of genomic surveillance should be raised significantly through cooperation with universities and other research labs. At the same time, research of new variants should be expanded.

Private-sector testing services are dealing with a growing number of samples, mainly in urban areas. These tests tend to fall through the government’s surveillance network. Quick actions are required to plug this hole.

Britain has failed to reduce the number of new cases despite restrictions in the operations of restaurants and bars and people’s activities. As a result, the British government has been forced to impose a new lockdown, making it illegal to leave home without a "reasonable excuse.”

Many medical experts in Japan warn that the nation is now facing the dire prospects of the buckling of hospital and health care systems nationwide.

In addition to measures to stem the spread of infections, the government should also take steps to prepare for the worst, including reconsidering plans for allocating hospital beds and securing the necessary human resources.

--The Asahi Shimbun, Jan. 12