Scenario Toward the End of COVID-19 Pandemic

A path to the new normal comes to view

Healthcare and Wellness DivisionSachiko Hirakawa

Mai Orii

Tomomi Nakao

Mihiro Shibata

Takeaki Taniguchi


  • Vaccines, medication, and measures against variants will bring the COVID-19 pandemic to a close
  • 2022 and 2023 will likely see substantial lifting of restrictions on activities
  • However, for the immediate, the world still requires restriction on activities, not only the widespread use of vaccines, to prevent spread of the disease
After three months under the country’s second state of emergency, Tokyo, along with the rest of the nation, enjoyed a respite from self-restraint in activities during the declaration from January to March. The first state of emergency, issued in April 2020, called for employers of a wide range of industries to either suspend or limit their operations and resulted in considerable impact on the nation’s economy*1. The second state of emergency took a less intrusive approach limiting self-restriction measures to venues for dining and appears to have achieved tangible results with a smaller impact on the economy.

Japan, and the rest of the world, are set to see repeated instances of COVID-19 spread and states of emergency in response. However, uncertainty remains to exactly when restrictions on activities will no longer be essential and when the pandemic will come to an end.

We developed a scenario for the end of the pandemic based on the opinions of experts in medicine, epidemiology, and public health in the Institute’s network *2. In the process, the end of the pandemic was premised on two conditions: flattened levels of infection and a sufficiently low fatality rate. Flattened levels of infection refers to the state in which numbers of those infected do not spike even without restrictions on activities. Lowering the fatality rate requires attaining levels as low as those for influenza where even if infected death is a rarity.

Vaccines and medication to bring pandemic to an end

Vaccination is essential to prevent further spread, and the addition of medication makes it possible to lower the fatality rate.

While most infected do not transmit the virus to others, a handful of cases, called super-spreaders, transmit the virus to multiple individuals; this dynamic differs largely from influenza.

The Japanese approach to preventing further spread has included identification of the source of infection through contact tracing as a measure for clusters, reducing instances of contact by restricting activities mainly in places that pose a high risk of infection, and promoting preventative measures such as masks, hand-washing, and sterilization. The Pfizer vaccine, which is being administered in Japan, is shown to have 95% efficacy in preventing the onset of disease; extensive use of vaccination will enable an end to many of the restrictions on activities otherwise necessary to prevent spread of the virus.*3

The fatality rate has decreased from 5.3% (as of May 31, 2020) at the early stage of the pandemic to approximately 1.9% (as of March 15, 2021) after physicians shifted their efforts from developing their own methods for treatment to establishing a standardized treatment by sharing information and coordinating efforts.*4 However, a definitive medicine has yet to surface, and fatalities have maintained a rate 60–95 times higher than that of influenza’s 0.02–0.03% rate.*5

There are particularly high expectations for the vaccination of elderly people for whom the severity of disease and fatality rates are high. In particular, forecasts envision a decrease in fatalities as well as a reduction in the burden on medical institutions.

However, variants of the virus may increase overall contagiousness, severity, and deadliness thus undermining the effectiveness of the aforementioned vaccines and medications; variants must be constantly scrutinized. (Figure 1)
Figure 1: Scenario of End of COVID-19 Pandemic
Figure 1: Scenario of End of COVID-19 Pandemic

Vaccines and medication to allow for easing of restrictions on activities

From February 22 to 28 this year, we conducted a survey on how the pandemic will play out and received responses from 21 experts in our network such as those in epidemiology and public health (Figure 2).

Views were almost equally divided among experts on restrictions for the remainder of this year: half thought that current levels of restrictions must be maintained, and the other half thought that restrictions will have been limited. However, almost all experts predict that restrictions will have become limited by the end of 2022. Furthermore, about a half of the experts see restrictions being fully lifted by the end of 2023. The next two yeas will serve as a crucial period for measures to produce successful outcomes; detailed reasoning follows below.
Figure 2: Predictions on Easing of Restrictions on Movement: Survey of opinion among experts
Figure 2: Predictions on Easing of Restrictions on Movement: Survey of opinion among experts

Outlook on Vaccines

In Japan, vaccination began in February 2021, and administration to the general public is scheduled for completion by the end of February 2022.*6 Herd immunity, or equivalent levels, has been forecast to require more than a year to vaccinate the required proportion of the population.

Immediate efficacy has been confirmed for multiple vaccines that are being administered including the Pfizer and AstraZeneca vaccines; however, the safety and efficacy remain unknown for the long-term. In the survey of experts, many predicted that the vaccine will remain effective for several months as in the case of the seasonal influenza vaccine.

Citing a study in which those having immunological memory of a cold were shown to have elevated levels of COVID-19 antibodies, one expert suggested that the disease may become something like seasonal influenza after the basic immunity is developed theoretically by a vaccine.

Commentary on vaccines (from the survey of experts)

  • Antibodies do not remain in sufficient levels for the coronavirus that causes the common cold. As COVID-19 too is a coronavirus, vaccines might fail to be effective over multi-year, long-term spans. However, vaccines are effective in preventing the development of symptoms and severe cases; COVID-19 might require annual vaccination as is the case for seasonal influenza. (Medical institution: clinical medicine)
  • Current COVID-19 vaccines elevate levels of antibodies against the seasonal cold, itself coronavirus. Vaccines provide patients with basic immunity even if they fail to provide lasting immunity to COVID-19. The pandemic will either continue in its current form or come to resemble seasonal influenza. Current vaccines should have a certain degree of efficacy against COVID-19 variants as well. (Medical institution: clinical medicine)

Outlook on Medication

No specific medication has been developed yet to treat COVID-19, and most of those under development remain confined to symptomatic therapy, or the application of existing drugs to control immune function. Experts were divided over the possibility for the development and commonplace use of medication in a way similar to anti-influenza medication.

Commentary on medication (from the survey of experts)

Optimistic commentary
  • Medication will be developed that, to some extent, inhibits the growth of the virus, eases symptoms, and prevents aggravation. (Medical institution: clinical medicine)
  • Efficacy of medications can be improved if M protein inhibitors are added to the RNA polymerase inhibitors, the base of most current medications. (Medical institution: clinical medicine)
Pessimistic commentary
  • In the case of COVID-19, replication of the virus reaches its peak and enters the decreasing stage soon after onset; the window is too small for antiviral medication to be effective even if such a drug was to be developed. (Microbiology/immunology)

Variants pose a major threat to progress

Variants threaten to undermine the gradual progress made in discovering methods to control the virus, with the first bunch starting to spread from the second half of 2020.*7 Four primary variants confirmed so far include: the UK variant (VOC-202012/01), the South African variant (501Y.V2), the Brazilian variant (501Y.V3), and the E484K variant, the origin of which is unknown.*8 Although the characteristics of each variant are under investigation, analysis of the UK variant demonstrates 25–40% higher rates of secondary infection and a 1.3 times higher degree of severity cases of those infected. Variants are representing an increasing percentage of cases in Europe and other areas; some areas, where the number of infections had been on a downward trend, are beginning to an increase again.

Sporadic infection by variants has been confirmed in Japan as well, and conventional prevention measures, such as behavior modification, may not be sufficiently effective. The current state requires sufficient measures to be made proactively.

Future prospects for spread and eventual end of pandemic

The COVID-19 pandemic can only be brought to an end if the effects of vaccines and treatments, which are factors that suppress spread of the virus, can surpass the threat of variants, which are factors that promote spread of the virus. Although many uncertainties remain about the timing of such factors, our comprehensive analysis of predictions from multiple experts concludes that restrictions on activities will be gradually eased with a substantial lifting of restrictions over the course of 2022 and 2023.

In other words, we must lead our lives understanding that restrictions on activities will remain inevitable until vaccines and treatments can produce sufficient effects to curb future spread.

*1:For the April-June quarter of 2020, the gross domestic product (GDP) decreased by 8.3% in real terms from the previous quarter, which is an annualized decrease of 29.3% (Source: Basic Policies for Novel Coronavirus Disease Control dated March 28, 2020 (revised on February 26, 2021) decided by the Novel Coronavirus Response Headquarters).

*2:Among experts in infectious disease with whom the MRI has connections, about 30 experts were requested to reply to a survey. They included those from the Expert Meeting on Novel Coronavirus Disease Control under the Cabinet Secretariat; the Advisory Board Meeting for COVID-19 measures of Ministry of Health, Labour and Welfare (MHLW); Infectious Disease Working Group Meeting of the Health Sciences Council, MHLW; and the Cluster Response Team of MHLW, and responses were obtained from 21 of them (February 21 to 28, 2021).
The specialized fields of the 21 experts who responded were basic medicine (microbiology/immunology): 2, clinical medicine (internal medicine): 4, social medicine (public health/hygienics): 11, and others (molecular biology, pediatrics): 2.

*3:The MHLW website “Instructions for the COVID-19 vaccination (Manufactured by Pfizer)” (accessed on March 3, 2021)

*4:The fatality rate was obtained by dividing the number of deaths by the number of infections (the number of PCR-positive cases).
The MHLW website “Coronavirus Disease 2019 (COVID-19) Situation in Japan (including the data published by the local governments on May 31)” (accessed on March 17, 2021)
The MHLW website “Coronavirus Disease 2019 (COVID-19) Situation in Japan (including the data published by the local governments on March 15)” (accessed on March 17, 2021)

*5:The Infectious Disease Working Group Meeting of the Health Sciences Council of MHLW (Document submitted by the National Institute of Infectious Diseases on January 15, 2021) (accessed on March 17, 2021)

*6:The MHLW website “Notice on COVID-19 vaccination” (accessed on March 3, 2021)

*7:The National Institute of Infectious Diseases “New variant of the novel coronavirus (SARS-CoV-2) that may have increased infectivity/transmissibility and different antigenicity (the 6th report)” (accessed on March 3, 2021)

*8:In media reports, they are referred to as “the UK variant or the South African variant.” These are common names that are used as the variants were initially confirmed in the respective countries.