Produced by | Tiger Sniff Medical Group
Author | Chen Guangjing
Caption | view of China
One more shot may be "lifesaving".
Preliminary analysis of the recent fifth wave of hong Kong deaths was announced. According to the report, which was provided by the Hong Kong Department of Health and analysed by the Hong Kong Hospital Authority, the median age of the deceased was 86 as of 13 April, and more than 95% were aged 60 and above. And 73 percent of them are not vaccinated.
An analysis of the deaths in Hong Kong, the fifth wave, found that 73% of them were not vaccinated.
From: Official website of the Government of the Hong Kong Special Administrative Region
Further analysis showed a mortality rate of 2.97 per cent for those who had not been vaccinated and 0.04 per cent for those with three doses of vaccine. In other words, three doses of the vaccine can reduce the mortality rate by 98.7%. Even a single injection can reduce the mortality rate by 67.3%.
"This is the experience of thousands of elderly people in Hong Kong who have exchanged their lives for real-world data, and I hope it can be taken seriously." Jin Dongyan, a virology expert at the University of Hong Kong, told Tiger Sniff.
The report calls for "a significant reduction in the risk of death with any three doses of the vaccine, especially in the older age groups"!
In fact, experts have been emphasizing the important role of vaccination for the elderly.
As early as the start of the fifth wave of the epidemic, virology expert Chang Rongshan proposed that vaccines are the best weapon to protect the human body. "The only thing that protects the human body 24 hours a day is vaccines." Especially the elderly , the older the age, the higher the risk. "The willingness to get vaccinated is already high now, but it needs to be extended to the entire elderly population."
At the beginning of the epidemic in Shanghai, Zhang Wenhong, director of the Department of Infectious Diseases at Huashan Hospital affiliated to Fudan University, also took Hong Kong as an example and proposed that the third dose of vaccine has an important role in preventing severe disease and reducing the case fatality rate. Especially the elderly, the elderly in nursing homes, if the third injection is given to strengthen immunity, the mask cannot be taken off. "Not getting vaccinated doesn't necessarily mean an accident, but most of the people who do are not vaccinated."
Zhong Nanshan, an academician of the Chinese Academy of Engineering, is even more practical, and in an online live broadcast for Nankai University on April 8, according to China's "dynamic zero clearance" strategy, the suggestion given is to "use heterogeneous vaccines as a sequential immunization", which can not only reduce the rate of severe illness and mortality, but also reduce the process of infectiousness. He himself has been vaccinated with the recombinant protein COVID-19 vaccine as a booster.
Why is the effect of one more shot of the NEW Crown vaccine significantly enhanced? Why are the seniors at highest risk getting vaccinated more slowly? Do the elderly at home who do not go out and have underlying diseases do they want to get this injection?
A reinforcing needle that can "save your life"
"Most of the fifth wave of outbreaks are breakthrough infections." In her report summarizing the epidemic situation in Hong Kong, Jin Dongyan wrote that the proportion of "most" is 81.8%.
In January 2022, at the beginning of Omicron's fifth wave of the epidemic, researchers studied the structural basis of Omicron's immune escape. In the paper, the researchers noted that there were 37 mutations in the spike protein of the new strain. Spike proteins are associated with human cell binding, and every mutation on it is worrying.
There are 15 and 11 mutations, respectively, in the RBD region and the N-terminal structure NTD where viral spike proteins (S proteins) bind to the human body, respectively, which cause severe weakening of plasma neutralization activity in previously infected or vaccinated individuals.
Of particular note is the RBD area of Omicron.
Previous studies have shown that Omicron is more likely to bind to human cells – the affinity of "key" RBD and "lock" ACE2 on human cells is about 2.4 times higher than that of the new coronavirus strain during the Wuhan epidemic. The study further found that the N501Y mutation on RBD alone increased the binding capacity of Omicron to human cells ACE2 by a factor of 6.
In addition, general VOCs (focusing on mutant strains) rarely mutate outside areas associated with COVID-19 infection and pathogenesis, such as RBD, NTD, and furan lysis sites. Omicron has eight more mutations outside of these three regions: T547K, H655Y, N764K, D796Y, N856K, Q954H, N969K, and L981F.
These points all play an inhibitory role in vaccine immunity or infection immune effects from different perspectives.
Under these combined effects, the Omicron strain not only has a stronger ability to spread, but also can more easily cross the barrier of natural immunity and vaccine immunity, resulting in breakthrough infections.
Under the stronger escape ability, the protective ability of existing vaccines has decreased significantly.
An article published by Zhang Wenhong's team on the preprint site on April 7 made it clear that two doses of inactivated vaccine are no longer sufficient to provide comprehensive protection against the new variant. Booster needles, whether homologous or heterologous, can reduce Omicron's escape from neutralizing antibodies.
The study also found that after the body was naturally infected with Delta, the antibody titer against Omicron was much lower than the level of the vaccination booster. That is, the neutralizing antibodies stimulated by the vaccination booster needle are higher than those of natural infection. The researchers believe that "this may be related to the differences in antigens between the Delta and Omicron variants."
Among the various sub-variants of Omicron, BA.2 is only more transmissive than BA.1, not immune evasion. The report also notes that the Omicron subphyla, such as the three recently reported recombinant lineages (XD, XE, and XF), are not significantly different from BA.1, BA.1.1, BA.2, and BA.3.
This also means that the widespread promotion of vaccines to enhance needle vaccination can still effectively prevent the infection and severe occurrence of Omicron strains.
This is also mutually verified with the latest research results of HKU researchers and Zhong Nanshan's team.
The University of Hong Kong study found that the protective power of the two-dose vaccine against Omicron was almost zero, and a new peak was reached after the third dose.
Jin Dongyan pointed out to the principle of tiger sniff analysis that this is mainly because after the body is exposed to the antigen again, the cells that can originally bind to the antibody will expand in large quantities, and in this process, the antibody will also mutate, becoming more and more affinity, and the neutralization ability will become stronger and stronger.
Academician Zhong Nanshan pointed out in the above-mentioned online live broadcast that through the analysis of the immunogenicity of the vaccine in the laboratory, it was found that after two doses of inactivated vaccine, the use of xeno-vaccine enhancement will make the serum neutralizing antibody level and specific CD4+ (RBD polypeptide library stimulation) activity achieve better results than three-shot inactivated vaccines.
He also released the results of a heterologous vaccination in Brazil, which also showed that the protection rate of vaccine infection after 6 months of vaccination with two doses of Koxing vaccine dropped to 34.7%, and the rate of severe disease prevention was 72.5%. At this time, if you strengthen an mRNA vaccine, the effectiveness of the vaccine against infection surges to 92.7% after 14 to 30 days, and the severity prevention rate reaches 97.3%.
Now Omicron spreads more and more insidiously, often forming a community spread when it is discovered. In this case, vaccination and building an immune barrier are undoubtedly very important foundations. In particular, Omicron can still be fatal for the elderly.
Protecting the elderly is key to the battle against Omicron
According to Jin Dongyan's summary, 99% of the current round of the epidemic in Hong Kong is mild and asymptomatic.
Nevertheless, the reality that cannot be ignored is that although Omicron is far less pathogenic than Delta, a certain percentage of patients will still be severely ill. Wu Zunyou, chief expert in epidemiology at the Chinese Center for Disease Control and Prevention, has said that the death toll caused by Omciron has surpassed Thatta.
The elderly are undoubtedly the weakest breakthrough.
The latest research shows that severe illness is likely to be related to the infection of immune cells by the new crown virus. Recently, researchers at Boston Children's Hospital wrote that monocytes and macrophages in the human body are the "outposts" of the human immune system, which can sense the invading infection and make a series of reactions to "kill" the invader, but under the mediation of the Fcγ receptor, the new crown virus may infect these two cells.
The "suicide counterattack" from these two cells, although it will stop the infection, will also trigger the pathogenesis of the new crown pneumonia and trigger systemic inflammation.
Researchers found that about 6% of monocytes infected with the new crown virus and had an inflammatory death in the blood of the dead cases; 1/4 of the macrophages in the lungs were dying, and further research found that 10% of monocytes and 8% of macrophages were infected by the new crown virus.
Researchers point out that severe illness caused by the new crown virus, characterized by acute respiratory distress, can lead to the development of multi-organ failure and death in the elderly and patients with comorbidities. Chronic increased inflammation is associated with aging, comorbidities associated with serious diseases, and severe diseases associated with signs of inflammation.
The elderly have poor resistance and often suffer from underlying diseases, especially major diseases of cancer, and this inflammatory response may also aggravate their pre-existing diseases. Because of this, they are the most at-risk group in the new crown epidemic.
This can also be clearly seen in hong Kong data, as of April 13, of the 8,735 deaths reported by the new crown virus in Hong Kong, 8,394 were over the age of 60, accounting for 96%. Among them, there are 6208 people over the age of 80, accounting for about 71%.
The above-mentioned study by experts at Boston Children's Hospital also showed that vaccine recipient plasma does not promote antibody-dependent monocyte infection.
Older adults without vaccine protection have proven to be at greater risk. The mortality rate of the elderly over 80 years old who have not been vaccinated against COVID-19 in Hong Kong is as high as 16.18%, which is 16.5 times that of their peers who have received 3 vaccines; among those aged 70 to 79, the mortality rate of those who have not been vaccinated is 38.9 times that of those who have received 3 doses of vaccines; and among people aged 60 to 69, the proportion is more than 50 times!
From: Official website of the Government of the Hong Kong Special Administrative Region
Omicron is the world's fifth wave of epidemic strains, the number of infections in Hong Kong exceeded one million; from January to March, the cumulative number of reported infections in 31 provinces and municipalities in China and the Xinjiang Production and Construction Corps reached more than 100,000; the number of daily infections in Shanghai also exceeded 28,000 at one point...
In this case, vaccinating the elderly against COVID-19, especially strengthening vaccination, has become the most powerful weapon against Omicron and the decisive battle against the new crown epidemic.
It shouldn't be a "dilemma"
However, many elderly people who were originally at high risk were not vaccinated in time. In this regard, Jin Dongyan analyzed that as far as Hong Kong is concerned, there are many reasons why the elderly do not vaccinate, on the one hand, the epidemic has been less before, and they feel that there is no need to fight; on the other hand, they are worried about side effects.
The elderly should be vaccinated at high risk, and they are worried that adverse reactions to vaccines will cause physical harm. This puts a lot of people in a dilemma.
"Inactivated vaccines are safer than mRNA vaccines, with more than 97 percent of people able to get them." Jin Dongyan told Tiger Sniff that there was also some misleading information at the beginning, such as thinking that people with immune problems and cancer patients could not be vaccinated, which later proved to be wrong.
It can be seen that in the latest "Technical Guidelines for New Coronavirus Vaccination (First Edition)" issued by the National Health commission, even patients with malignant tumors can be vaccinated against the new crown. Zhang Hongtao, a doctor of pharmacology in the United States, stressed in his article that as long as these cancer patients are not feverish or in the acute treatment period or uncontrollable, they can be vaccinated against the new crown.
At the State Council's joint epidemic prevention and control press conference on April 1, Wang Qinghua also listed only a few suspensions of vaccination, including: fever or chronic diseases are in an acute onset period, and some related diseases such as Green Bary, transverse myelitis and demyelinating disease can be postponed if they are not controlled.
The death of thousands of elderly people in Hong Kong due to the epidemic is a tragedy. In order not to repeat the tragedy, Hong Kong is also vigorously promoting COVID-19 vaccination.
Judging from the official website of the Hong Kong Special Administrative Region, the vaccination rate of the elderly population has increased significantly, from less than 20% at the beginning to more than 60%. The proportion of two doses also increased to 48.28%.
At the same time, they are also promoting the fourth injection of vaccination for the elderly. According to the local government notice, people over the age of 60 who have received three doses of the vaccine can receive a fourth dose of the vaccine at least 3 months after receiving the last dose of the vaccine to strengthen the protection.
"Mainly for those who have weak immunity, under the guidance of a doctor, they are planted until they form a certain level of neutralizing antibodies." Jin Dongyan explained to Tiger Sniff.
Chang Rongshan told Tiger Sniff that it cannot be thought that the elderly can not be vaccinated without leaving home. In fact, in the past outbreaks, there have also been cases where the elderly who stay at home have been infected.
"The characteristics of Omicron are that ordinary physical prevention and control are ineffective, the transmission force is extremely strong, there are many asymptomatic infected people, the infection rate of young people is high, and the active population does not need to be hospitalized even if they are infected, they will surround the elderly population; once a certain area is suddenly prevented, the total infection rate of the whole community can easily exceed 1%, so that the chain of infection will definitely extend to the elderly group, and there will be severe diseases, if there is no vaccination, the elderly will die after infection is unstoppable." Chang Rongshan said.
He believes that in order to ensure the effectiveness of vaccination, the elderly should also be added to the antibody test after vaccination to ensure that they have anti-covid-19 neutralizing antibodies above the protective threshold. Antibody detection after immunization confirms the protection threshold, antigen screening at the beginning of the epidemic (to ensure that the elderly can stay at home, full static management at home), once the antigen is positive, the nucleic acid single collection is entered, and the "antibody, antigen, and nucleic acid" are three-pronged to form an all-round protection for the elderly population.
According to Lei Zhenglong, deputy director of the Disease Control Bureau of the National Health Commission and a first-level inspector, in response to a reporter's question, as of the beginning of April, 224 million elderly people over the age of 60 in China had been vaccinated against covid-19; of which 213 million people had completed the whole process of vaccination and 144 million people had completed enhanced immunization.
According to the seventh national census, there are 264 million elderly people aged 60 and above in China.
This means that at least 42 million elderly people in China are still completely unvaccinated, more than 100 million people have not completed boosted immunization, and once Omicron forms a community transmission, they will be in danger first.
From the overall data, the overall two-shot vaccination rate of the elderly in Chinese mainland is less than 81%. In Beijing and Shenzhen, the vaccination rate of the elderly has just reached 80% and 67%. Of the cases reported in Shanghai on 14 April, nine were also severely ill and unvaccinated, eight of which were elderly people over the age of 70 with underlying medical conditions.
The most at-risk population over the age of 80 has a three-dose vaccination rate of less than 20% in Hong Kong, and according to a press conference on April 12, the vaccination rate of the third dose of the Chinese mainland vaccine is less than 20% - about 19.7%.
In this sense, vaccinating these elderly people is also reinforcing the weak links in prevention and control in the fight against the epidemic. Lei Zhenglong appealed that in addition to the need to postpone vaccination, it is hoped that the elderly will complete the whole process of vaccination in a timely manner in accordance with the procedures, and meet the conditions to complete the enhanced immunization in a timely manner.
According to some scholars, the current countries with high vaccination rates of the elderly population in Asia, such as Japan, South Korea and Singapore, have a two-shot vaccination rate of more than 90%, of which Japan and Singapore have reached 98% and 94% respectively.
"The official goal in Hong Kong is already to increase the vaccination rate of the elderly with two doses to more than 90%, and the third dose should be increased as much as possible." Jin Dongyan introduced to Tiger Sniff that in order to promote this work, Hong Kong has even launched the form of houses and cars in the vaccination lottery.
At the same time, Beijing, Shenzhen and other cities are also renovating to encourage the elderly to vaccinate in the form of shopping vouchers, milk, edible oil, and even direct cash.
The next "battle" to protect china's elderly can be described as a difficult task.