The dawn of unblocking is not far away. The virus mutates fiercely! Will the mutant strain of the big devil "XBB" invade Taiwan during the New Year? Failure to vaccinate may result in 5,000 more serious illnesses
The end of the lockdown is not far away, is there still time for the virus to mutate?
The emergence of COVID-19, a century-old pandemic, has caused earth-shaking changes in human society. With the large-scale spread of Omicron mutant strains and the popularization of vaccines, many major countries have adopted unblocking measures. Taiwan will also gradually move towards full opening up and coexist with the epidemic. However, as the virus continues to mutate, will it trigger the next wave of epidemics? ? To this end, the “Taiwan Screening Society” organized “Omicron Variants and Next-Generation Vaccines”, inviting experts from all walks of life to review and discuss trends in mutant viruses and vaccine and pharmaceutical development from multiple perspectives: biological evolution, clinical medicine, and public health policy.
Dr. Lai Zhaozhi from the Emergency Medical Department of Taipei City Hospital said that coronaviruses have existed in nature for a long time. Humanity has experienced three waves of coronavirus epidemics: from SARS, MERS to COVID-19 (SARS-CoV-2), the first two very quickly The intermediate host and source of the virus have been identified, but it is still unclear how COVID-19 spread from zoonotic to human in such a short period of time. Another theory is that the genetically recombined virus in the laboratory was accidentally leaked, but there is no clear evidence to support this argument.
“The SARS-CoV-2 virus has evolved from the Wuhan strain at the beginning to the highly adaptable Omicron strain by the end of 2021. Omicron is almost the dominant strain throughout 2022. The virus has evolved from slow transmission and high mortality to Later, the spread speed became faster and faster, and it gradually found its way under the attack of adapting to the human immune system! "
The “brothers and sisters” of the two most worrying viruses, mutant strains, will automatically recombine
Dr. Lai Zhaozhi explained that through today’s advanced genetic research instruments, the direction of change of the viral S protein mutation site can be discovered and even predicted, especially the changes in the three-dimensional structure of the RBD. For example, the D614G mutation allows the virus to bind more easily to the ACE2 receptor. for closeness. The mutation of the RBD of the virus significantly reduces the protective power of neutralizing antibodies stimulated by the vaccine, resulting in the virus having a stronger immune escape ability. It is still unclear whether mutant strains with both the ability to spread rapidly and the incidence of severe disease will evolve in the future. .
Dr. Lai Zhaozhi pointed out that Omicron mutant strains show at least two hidden concerns. One is that the mutation site of the S protein is constantly changing, and the other is that different mutant strains will automatically recombine between “brothers and sisters” to produce new mutant strains such as “Deltacron” . Scientists are worried that the evolution of the Omicron virus from BA.1 to BA.5, and even the current “BQ1” in Europe and the United States, as well as the “XBB” virus strain that caused a wave of epidemics in Singapore, may set off another wave of global pandemics. ?
“Although we can use AI machine learning to predict the direction of future virus mutation, some scholars believe that the mutation site of the virus is unmeasurable, and different site mutations will affect immune escape and the ability of the virus to bind to ACE2, leading to real-world The protective power of the vaccines among them is getting lower and lower, which is an important reference for the development of new drugs and next-generation vaccines!”
Vaccine R&D and virus competition, humans are like Kuafu chasing the sun
Jiang Guanyu, an attending physician at the Department of Integrated Medicine, Taipei City Hospital Zhongxing Branch, pointed out that in order for the new coronavirus to infect the human body, it needs to undergo complex processes such as joining, cutting, and fusion with cells. The key S proteins that cause infection are divided into S1 and S2. S1 contains the affected cells. The body binding domain (Receptor-binding domain, RBD) is responsible for joining with the cell membrane surface receptor (angiotensin-converting enzyme 2, ACE2), and S2 is responsible for regulating the fusion of the virus and the host cell membrane. As the COVID-19 virus continues to spread and infect, it produces mutations at various sites on the S protein and undergoes “convergent evolution”, moving one after another toward the goal of continuously increasing its infectivity.
“Judging from recent data on bivalent vaccines and feedback from immunological research, the competition between human development of vaccines and viruses can be said to be a ‘Kuafu chasing the sun’. Humanity is actually losing. The development of vaccines is currently We can’t keep up with the speed of the virus!”
Dr. Jiang Guanyu said that taking the strategy of administering bivalent vaccines as the fourth dose as an example, the United Kingdom and the United States have different considerations for epidemic prevention. The UK chose the BA.1 bivalent vaccine. Although the overall effectiveness was only improved by 8%, it still achieved the strategic effect of reducing the burden of severe medical care. In comparison, due to the poor willingness to administer the vaccine in the early stage and the long interval between the third and fourth doses, the United States directly administered the BA.5 bivalent vaccine, which indeed produced a greater increase in protection.
Influenza infection still poses a fatal threat. Elderly persons at high risk should receive the bivalent vaccine as soon as possible.
“The epidemic situation seems to be getting smaller and smaller, but it is impossible to predict what kind of mutations there will be in the future. Although the protection of the vaccine against variant infection has been significantly reduced, for high-risk groups, the vaccine has a clear ability to prevent severe disease and reduce the risk of infection. Mortality effect──The vaccine that can be injected into the body is the best vaccine!”
Dr. Jiang Guanyu shared that a confirmed case was recently admitted to the dedicated ward. He had a history of breast cancer and had received radioactive treatment, as well as a history of diabetes and heart failure, but had never been vaccinated. Interstitial pneumonia was suspected to have occurred several days after the diagnosis and hospitalization. Another middle-aged man received three doses of the vaccine but still developed severe pneumonia and multiple complications after infection. He is currently under hospice care. This shows that even if the virus has weakened, the lethality caused by attacking high-risk groups and the elderly cannot be underestimated.
“The latest evolved XBB virus strain is even called the ‘King of Cell Membrane Fusion’. Its infectivity and immune escape are even more powerful. In order to protect high-risk groups, the supplementary dose should be administered as soon as possible!”
Excess deaths increase by one-third; without vaccination, 5,000 more severe cases may occur
“The most unexpected thing about COVID-19 is that I thought that the arrival of a vaccine would mean the epidemic would come to an end. I didn’t expect that various mutant strains would continue to evolve into new “big devils” and set off waves of infections. Take Taiwan’s June 2022 outbreak alone. The number of “excess deaths” in March increased by nearly one-third compared to last year!”
Professor Yan Mingfang from the Department of Dental Hygiene at Taipei Medical University pointed out that in addition to causing breakthrough infections, viral mutations may also lead to repeated infections over time. Assuming that the transmissibility of the XBB virus strain is estimated, without additional doses of vaccine, it is expected that more than 10,000 more moderate cases and more than 5,000 severe cases will increase. In addition, indirect deaths caused by non-infection, including failure to receive timely medical care, and subsequent complications caused by infection in the elderly and immunodeficient groups must be taken into consideration.
“Many voices are discussing whether to give a booster dose? Judging from the data, the direct mortality rate of the booster dose of the vaccine has dropped by 3/4. Although the virus is becoming influenza-like, the complications and deaths after infection in high-risk groups More attention is needed. Don’t wait if the existing supplements are available!”
Professor Yan Mingfang said that the actual protective power produced by the additional dose of the vaccine is between 73% and 75%. However, if NPI measures such as wearing masks and other measures are added, the protective power is expected to be pushed up to 90% by December. Chances are the mortality rate will drop by 0.5 per 100,000. It is worth noting that the epidemic curves in Taiwan and New Zealand are like “digital twins”. There may still be a small wave of epidemics rising in the future, especially during the upcoming New Year’s Eve and other large-scale events. Will the XBB virus take advantage of the situation and cause a new wave? Infections are rising and must be monitored carefully.
The right to wear the masks you should wear to prevent the epidemic is back in the hands of the people
“First, believe in science and evidence. Second, hurry up and get the next-generation vaccine. This is the reminder from American epidemic prevention expert Fauci at his last briefing recently. The epidemic has entered the next stage, and the choice of epidemic prevention will slowly Return it to the people themselves!”
Hong Ziren, deputy director of Shin Kong Hospital, said that the epidemic situation has changed significantly since this year. The mutant virus no longer violently attacks the lower respiratory tract, but has increased the demand for chronic disease care in dedicated wards. The public health and medical departments also responded as quickly as possible, reducing the burden on medical manpower by introducing caregivers and other methods. When epidemic prevention is gradually opened up, wearing masks is no longer a mandatory requirement, but people must be responsible for their own health, and they must not neglect the epidemic prevention and vaccination that should be done.
Vice President Hong Ziren suggested that the effectiveness of vaccines in preventing severe illness and death is obvious. High-risk groups such as the elderly and those with chronic diseases are strongly recommended to receive next-generation vaccines. For people under the age of 50, it is recommended to take the basic dose and the third dose to the full dose. In the future, it is necessary to study whether to conduct a large-scale serum sampling survey to understand the true community infection rate in Taiwan, which will serve as a basis for formulating further prevention and control policies.
The virus pandemic will not last more than three years? Next generation vaccines and drugs are key
Professor Chen Xiuxi from the School of Public Health of National Taiwan University said that the speed at which the COVID-19 virus generates mutation sites is indeed unprecedented. Changes in any position between the N-terminus and the RBD-terminus of the virus structure may affect the amount of virus and its ability to bind to ACE2. The virus mutates as fast as the wind, making it more difficult to predict the effectiveness of vaccine administration and increasing the complexity of vaccination intervals, all of which have become difficult problems in epidemic prevention.
Professor Chen Xiuxi reminded that as the protective power of vaccines decreases, high-risk groups may be infected with T cells that cannot function normally, and may suffer from complications caused by subsequent infections or even “grow COVID-19”, resulting in more health risks. Until a broadly effective vaccine against RBD mutations is available, vaccination with next-generation vaccines is still a necessary measure to suppress the epidemic and reduce the risk of moderate to severe disease.
Professor Chen Xiuxi pointed out that from the perspective of human history, a pandemic would not last more than three years at most. It took 50 or 60 years for the influenza of the last century to develop a vaccine as a public health weapon. Nowadays, humans not only have mRNA vaccine technology, but also machine learning and AI smart technology. In response to the changes in Omicron mutant strains, we hope that the industry will pay attention to and develop newer vaccine and drug projects. Public health policies and government epidemic prevention responses should also maintain dynamic adjustments to help Promote overall social health in the post-epidemic era and protect high-risk groups from the threat of the disease.
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