This article is part of a series on important coronavirus-related information. Click here to read other installments: #Coronavirus the facts. Find the latest information on everything COVID-19.
Preparing for winter
As COVID-19 infections edge higher across Japan, experts are concerned that a new wave of cases is approaching. They're also worried that an influenza outbreak could strike at the same time and place extra pressure on the medical system.
Several factors are behind the influenza fears. Since the COVID pandemic began in 2020, Japan has not experienced a flu outbreak, most likely because of the various anti-infection measures enacted. That means immunity is low at the same time as border controls are relaxed and social activity resumes.
Vaccines, antigen test kits and medication
Health officials in Japan want people to prepare for a possible double outbreak by receiving vaccines for both coronavirus and flu. They are also encouraging households to stock up on ministry-certified antigen self-test kits and fever-reducing medication, and have a medical consultation plan in case of illness.
Low takeup rate for Omicron vaccine
The vaccine that targets the Omicron COVID subvariant has been available in Japan since September. As of November 10, only about eight percent of the public had taken it up. Authorities want to improve that figure as a matter of urgency.
*Related article: Omicron BA.5 vaccine in Japan (Oct. 27, 2022)
The Australian example
During the southern hemisphere winter, Australia experienced its first flu outbreak since COVID. Infections were at a similar level to pre-pandemic, and the peak arrived in June, two months earlier than usual.
Officials worry that the same thing could happen in Japan with a double outbreak of COVID and flu putting medical institutions under strain. Those concerns are tempered slightly by the fact that social contact in Japan is yet to return to how it once was.
Toho University Professor Tateda Kazuhiro, a member of the Japanese government's panel of experts on the coronavirus, says it's important to consider overseas infection trends. But he notes that many countries and regions that have experienced influenza outbreaks had already stopped basic anti-infection measures such as mask-wearing.
Double infection increases health risk
One study published in March in the British medical journal The Lancet found that simultaneous flu and COVID infections increase the risk of serious illness or death. The research, led by groups from the University of Edinburgh and other institutions, studied about 200 people who were infected with both flu and COVID together, among a group of 7,000 people with COVID-19.
The findings showed that for people with a double infection, the risk of getting serious illness and having to receive artificial respiratory assistance increased by 4.14 times. The risk of death was 2.35 times higher.
Nagasaki University in Japan also conducted a study last year that found hamsters with simultaneous COVID and flu infections suffered more severe lung inflammation and delayed recovery.
Assessing risk
Japanese authorities are trying to avoid a scenario where medical institutions are overwhelmed by a double outbreak.
High-risk patients
High-risk patients such as the elderly and people with underlying medical conditions are encouraged to visit clinics as soon as they experience symptoms including sore throat or fever. They should consult their own doctor if they have one, or make use of call centers for advice.
Low-risk patients
People in the low-risk category are asked to self-test and recuperate at home if they experience mild symptoms. If they test positive, they need to register the result with municipal health centers. If symptoms worsen and they require medical attention, ring a call center.
This information is accurate as of November 11, 2022.