1. Introduction
The COVID-19 pandemic has spread worldwide, leading to physical disabilities and countless deaths [1-6]. Countries have implemented various measures to respond to the pandemic. Some countries, such as Iceland and Taiwan, have successfully contained the virus by conducting frequent polymerase chain reaction (PCR) tests and quickly identifying new cases [7-9]. Others have attempted to lockdown areas to contain the spread of the virus. However, the effectiveness of these measures varied greatly, with many countries experiencing delayed epidemic detection and inefficient disease control. The effectiveness of frequent PCR testing and strict lockdown has been demonstrated in China, Australia, and New Zealand [10, 11]. However, with the emergence of the more infectious Omicron variant, strict lockdowns were inadequate. At that time, residents began to protest against the lockdowns, and the governments terminated the lockdown policy without any consideration for a soft landing [12-14]. Many other countries, such as Japan, have not conducted sufficient PCRs, making it difficult to understand the trends of the infection [
11]. In some countries, such as Sweden, lockdowns were not implemented and the public was left to make their own decisions [
15]. In these countries, the epidemic progressed regardless of the residents’ self-help efforts. Thus, it is important to compare the differences among the effects of these measures.
The technical difficulties of identifying trends in the patient population, which can rapidly increase or decrease, may be responsible for these failures in detecting epidemics. Hence, adaptation to the Susceptible–Infected–Recovered (SIR) model is difficult. It targeted a rather limited number of people, and the period of logarithmic increase was very short, so there is little point in estimating R0 [
16]; this would be because viruses that were not originally human viruses gradually acclimatised to humans. Those that become more infectious, repeatedly penetrate defence systems and cause epidemics [17, 18]. When switching hosts, the mutation rate is particularly rapid, and infectivity becomes stronger [
19]. Therefore, the most recent Omicron variant, which has persisted for over a year, is highly infectious [
20]. Moreover, the parameter R0, which the SIR model originally emphasised, has a lognormal distribution, is mathematically unstable, and requires complicated calculations to be estimated precisely [
16]. This makes it difficult to use as an indicator of trends. Therefore, it is more realistic to work with a logarithmic growth rate K, which has a base value of two. This is not only easy to calculate but also suitable as an indicator of the epidemic phase. The changes in
K are shown in the following actual data.
SARDS-CoV-2 underwent significant mutation during the pandemic. Therefore, the messenger (mRNA) vaccine, which initially showed great promise, was no longer effective in containing the epidemic and was unlikely to reduce the disease severity effectively. The vaccine design could not keep pace with this mutation.
This study provides a comprehensive analysis of the effectiveness of various government policies in response to the COVID-19 pandemic. By identifying the effective strategies for containing epidemics, this study can help guide policymakers in their decision-making for containing COVID-19 as well as preparing for future pandemics.
4. Discussion
Strict policies such as lockdowns were unsuitable for controlling the pandemic, which would be a long struggle (
Figure 3D, S2A, S2L). Furthermore, a soft landing strategy is required to lift strict policy [
12]. Isolating infected people can also be achieved through a lockdown; however, this places a heavy burden on the population, and it should be noted that Iceland did not opt for this [
8]. Naturally, many citizens will oppose a lockdown, which will put pressure on politicians [
51]. The leaders of Australia, New Zealand, and China, who had well-controlled epidemics by strict lockdowns, withdrew their Zero-COVID policy [10, 13, 14]. This led to an epidemic (
Figure 3C, 3D, S2A); it is likely that people accustomed to the lockdown had no means of self-defence. Some countries have stopped tracking their number of patients [
1]. In contrast, Sweden still does this, so the mortality rate can be inspected; however, other dispirited governments could abandon all that needs to be done. This is another disadvantage of lockdown. The successful experience of containing the infection will lead to neglecting the essential need to establish a method for detecting patients. This not only makes early treatment impossible but also damages infection control after the lifting of the lockdown.
The mRNA vaccine, an entirely new technology [
52], has effectively prevented older variants [
11]. However, it was ineffective against newer variants such as Delta and Omicron (
Figure 1B); such variants have gone through selection pressure of the vaccines and are in vogue. Altering the mRNA sequence was required [
53]; in a molecular biology sense, it was supposed to be a simple operation [
52], but it took much longer than expected, and the new antigens were not effective. This is probably a task with difficult problems that can only be known by the person concerned, and this should be remembered as it is difficult to keep on changing the vaccine design for changes in viruses. Hence, mRNA vaccines can only be relied upon for a short period, and different policies are required.
mRNA vaccines are expected to reduce the severity of illness and mortality; however, this appears to be largely unrealised [26, 54, 55]. The reduction in mortality rates was probably due to the low lethality of the early Omicron variant [
26] and not due to the vaccines (
Figure 1C). In some countries, mRNA vaccines up to the Delta variant might have been able to reduce mortality (
Figure 4). However, this effect was much weaker for the Omicron variant, although we wanted to obtain more data to confirm this. Especially in the USA, the situation is somewhat unique; there would be a difference in access to healthcare between those who received free and easily available vaccines and those who did not. The latter must include many anti-vaccine people [
56], who never trust modern healthcare. It is easy to imagine that delayed medical intervention for infections with the highly virulent Delta variant would increase mortality. This readily presumed difference confounds the epidemiological estimates. Therefore, the results [
57] should not be taken for granted. Indeed, at least on a global scale, the Delta variant was in epidemic proportions when vaccination coverage reached 100 %, but mortality was only marginally reduced at this stage (
Figure 1C and S2U).
Reducing the number of anti-vax [
58] people is also a task for the government. Public trust in the government reduces each time the government implements counterproductive measures, which may lead to growing distrust in healthcare, and the number of anti-vax people will probably increase. Such a situation was observed in Japan. A group of experts, who are supposed to give their opinions to the government (but are rarely listened to), recommend that people stay away from densely populated areas and wear masks; however, the anti-vax people protest these recommendations. They say that they do not need expert opinions and that they should decide for themselves on how to live their lives. Unfortunately, if these individuals are infected, they will spread the virus, and if it is too late, they will die. To avoid an increase in the number of these people, it is essential to inform and educate them closely and not overwhelm them. For the mandatory quarantine of infected people, there must be a legal backing. Of course, it would not make sense to isolate patients without adequate medical treatment. Moreover, continuing to recommend ineffective vaccines will further undermine their confidence.
Why governments have not been proactive in publishing data on mortality and vaccination despite their importance to public health is unnatural and questionable. If vaccines really reduced mortality, the greatest publicity for vaccination would come from these data. In Japan, despite the government's aggressive promotion [
59], there is now a surplus of mRNA vaccines that are being discarded [
60]. If the effect of the reduction in mortality has already been lost, this would be an inconvenient truth for the government, which has been requested to explain the huge unaccounted budgets [59-62]. Vaccines have lost their efficacy in preventing epidemics (
Figure 1B). If vaccines do not reduce mortality, then there are no benefits left but only risks [63-65] in present vaccinations.
It should also be noted that infectivity increases even during a pandemic (
Figure 1A). This reduces the validity of effective measures in the early days, such as distancing, masking, vaccination, and lockdown. The first SARS-CoV-2 in this epidemic was not a human virus; rather, it could have been a bat virus that had been maintained in Vero cells and had become infectious to primates. In the process of human-human infections, the virus rapidly mutates to acclimate to humans in several directions [17, 18], one of which is Omicron [
20], the variant with the highest infectivity. This variant reduced the mortality rate, but this was coincidental because the virus was originally asymptomatic in many people; hence, weakening the virus is not subject to selective pressure. We should not always count on such good fortune. If the next pandemic were influenza H5N1, for example, it would be a mutant that could infect mammals, pass through an intermediate host, such as a pig, and then infect humans [
66]. In this case, the virus changes rapidly among humans [
19], altering its epitopes and increasing its infectivity. However, if we can converge in the initial stage, we can avoid a pandemic before it occurs. This is the only stage in which a lockdown should be implemented. Therefore, a system that can quickly identify and alert the public about new infectious diseases is required.
The epidemic has subsided in some countries (
Figure 2 and S3). SARS-CoV2 has several conserved open reading frame (ORF)s [17, 20]; this is a major difference from influenza, where all ORFs mutate at equal rates [
67]. Presumably, SARS-CoV2 cannot repeat reinfection, such as influenza, over the decades. As people become less immune, what is needed would be multivalent vaccines, especially ones that can be used by developing countries [19, 20].
Data on daily changes in confirmed cases are important for fully ending the epidemic. As the number of infected individuals has declined, several countries have stopped reporting daily data [
1]. In the USA, for example, data are reported only once a week; in Australia and New Zealand, this has become even more irregular. This is a serious public health problem because an accurate
K cannot be estimated without data. This causes not only the rapid increase but the decrease is unmonitored to maintain the decreasing state. According to the SIR model, the number of patients decrease exponentially [
16]. However, this phenomenon was not observed in these countries. Although the numbers are declining, small epidemics still recur, resulting in patient numbers ranging from tens to several thousand (
Figure 2B, 2C, S1A, and S1L). The exponential decrease is fast at the beginning, but becomes increasingly slower. Complete convergence is difficult to achieve if the government cannot maintain the motivation to keep the
K low. While we would like to see the development of effective vaccines and certain drugs, the government should not depend on them, but do what needs to be done first. The only way to ultimately end this problem is to continue identifying and isolating patients, a task that should be the government's responsibility.
The inability to contain causes problems, because the remaining patients include a larger proportion of vulnerable people. They could be those with underlying diseases who have carefully avoided infection, and those who fail to acquire immunity and become infected repeatedly. This was also likely to occur in individuals who had been vaccinated many times [
68]. Therefore, they are more likely to be critically ill [
69]. This disease can cause systemic symptoms [
70] and long-lasting sequelae [2-5, 71] in more than 10 % people, and this rate is likely to become more dismal in the future as the proportion of vulnerable people increases. The UK and Sweden may not have enough patients to cause a medical collapse now; however, their mortality rates have remained high, approximately 2 % (
Figure 3E, 3F). Even in the USA, where there may be a wider choice of medical care, the mortality rate is 1 % (
Figure S2R), which was quite high compared to the global data (
Figure 1B). There is no other way to save vulnerable people but to bring the COVID-19 epidemic to a complete halt.
Many countries have estimated the COVID-19 pandemic to be smaller than reality, albeit to varying degrees (
Table S1). It is likely that the detections were not performed on time, which is a failure in terms of testing and isolation. Although the survey was probably closer to random sampling, there was a crucial difference in that the sample size was unknown. Therefore, the total number of patients and deaths is not necessarily known. In particular, most African countries probably do not investigate or respond to cases of infection; therefore, the number of reported cases in Africa is so low [
1]. These can only be estimated in some way. A promising method is the estimation of excess deaths [6, 47-49]. However, this estimation is disputed; indeed, there is no evidence that the deceased were COVID-19 patients. For example, a stroke victim may have died because they did not receive timely medical care. However, that person would probably have been saved during regular times, and this could be considered a death caused by the COVID-19 pandemic.
The damage is an order of magnitude greater if we do not have a leader who pays proper attention to public health or at least takes expert opinion (
Table S1) [34, 35, 45]. This can be seen from the ten-fold increase in mortality rates in Japan, where many healthcare resources were allocated to host the Olympic games (
Figure 3A). This does not depend on the country’s principles. There should be a system through which the scientific community can adequately advise the government. However, in Japan, this system does not work satisfactorily. In January 2023, Japan had over 10,000 recorded deaths, which should be times higher [6, 44]. Nevertheless, the government has made a cabinet decision to exempt COVID-19 patients from quarantine and is campaigning for people to stop wearing masks [72-74]. In addition to limiting the number of PCR tests, the government abandoned counting cases, stating that it would announce the number of deaths after two months [
75], thus hiding the issues from the people. Additionally, they are still pushing forward with mRNA vaccination [
59]. How unscientific these are is beyond dispute [63-65, 68, 76-78]; these unscientific policies will definitely affect many patients, including vulnerable ones. Clearly, the government does not want to take responsibility for public health. One of the desired roles of experts is to examine the policies and appeal to voters so that they do not elect inappropriate leaders. The removal of unscientific politicians should probably be the immediate measure undertaken for managing public health effectively.