As the country with the highest number of new crown vaccines per capita in the world, Israel is considering reinstating the indoor mask order under pressure from BA.5 less than two months after taking off its masks on April 24 this year.
With the Omicron variant BA.5 accounting for 70% of the population in Israel, the daily number of new cases in Israel has once again exceeded 10,000. In late May, the daily increase in Israel dropped to less than 2,000 at one point.
On June 19, local time, Israel reported that 10,202 people tested positive for the new crown nucleic acid, and the positive detection rate reached 27.9%.
Nachman Ash, director general of the Israeli Ministry of Health, said on June 19 that a new wave of infections may have arrived. Nachman Ash pointed out that in the early stages of the new wave, the Ministry of Health does not intend to impose broad restrictions on large gatherings as before. However, the Ministry of Health is considering reintroducing the mask-wearing rule in enclosed public spaces.
With BA.5 gaining ground in Israel, Israeli experts say the possibility of including a fifth shot for the elderly and immunocompromised should be considered.
In fact, the BA.4 and BA.5 mutant strains under Omicron are also emerging in the United States, setting off a new wave of infection.
The latest data from the US Centers for Disease Control and Prevention shows that as of June 11, the combined BA.4 and BA.5 accounted for 21.6% in the United States. On May 7, the merger of BA.4 and BA.5 accounted for only 1% in the United States. This means that in 35 days, the combined share of BA.4 and BA.5 has soared by 21 times. Among them, BA.4 accounted for 8.3%, and BA.5 accounted for 13.3%.
The European Centers for Disease Control and Prevention recently said that BA.4 and BA.5 spread faster than other Omicron variants and could lead to more hospitalizations and deaths.
BA.4 and BA.5 have a key mutation in the spike protein: L452R. The L452 site mutation is the spike protein mutation site that Omicron BA.1 and BA.2 mutant strains do not have, but Delta has. The spike protein plays a key role in the entry of the new coronavirus into human cells: it can bind to the ACE2 receptor of human cells and invade across the cell membrane. target.
At present, BA.4 and BA.5 have become the dominant variants in Portugal, although the vaccination rate in Portugal exceeds 85%, and it has just experienced a large number of Omicron BA.1 and BA.2 from the end of 2021 to the beginning of 2022. Infection, a new wave of infection still appeared in Portugal, and the positive detection rate was as high as 50.63%. The number of new deaths has also returned to the level at the peak of Omicron infection in January-February 2022.
Further reading: BA.4/5 replicates efficiently in human alveolar epithelial cells
The pathogenicity study of BA.4/5 was previously jointly published on the medical preprint website bioRxiv by 27 research institutes including the University of Tokyo, Kyoto University, Hokkaido University, Kyushu University, Kobe University, and Israel's Weizmann Institute of Science. Heavy research shows that the replication efficiency in human alveolar epithelial cells is higher than that of BA.2, especially BA.4 and BA.5 have stronger cell fusion ability in alveolar epithelial cells than BA.2.
In order to test the replication ability of many mutant strains of Omicron in human alveolar epithelial cells, the research team prepared a chimeric recombinant SARS-CoV-2 virus with L452R mutation through reverse genetics. The experiments showed that BA.4, The plaques formed by BA.5 infection of human alveolar epithelial cells were larger than those formed by BA.2 infection. The researchers also found through experiments that BA.4 and BA.5 were much more efficient than BA.2 in replicating human iPSC-derived alveolar epithelial cells.
Further reading: Breakthrough infection and superinfection of Omikron
The new coronavirus Omicron variant has swept the world, infecting hundreds of millions of people. Because the symptoms caused by Omicron are lighter than Delta, and natural infection can bring certain immunity, some voices believe that the Omicron variant is a natural booster. However, the latest research reveals that the effect may be the opposite: infection with the Omicron variant after vaccination may not necessarily lead to a boost of immunity, and may also weaken the immunity to the new variant later.
The above conclusions come from a recent heavyweight study published in the international authoritative academic journal "Science", "Immune boosting by B.1.1.529 (Immune boosting by B.1.1.529 (Immune boosting by B.1.1.529) Omicron) depends on previous SARS-CoV-2 exposure).
The study, led by researchers at Imperial College London in the UK, looked at how complex patterns of population immunity following vaccination and previous infection influence people's future protection against SARS-CoV-2.
The official website of Imperial College London stated that the study found that the immunity brought by infection with Omicron is very poor in response to the natural immunity enhancement provided by re-infection of Omicron itself. The same goes for people infected with Omicron.
The core issue here is "Immune imprinting". In layman's terms, the body's immune pattern against the new coronavirus will be "imprinted" on the immune system through the history of infection. Each individual's immunoblot depends on the number of vaccine doses they have received and the variant they have been exposed to. This results in different immunity in different individuals in the population.
The ability of an individual's prior SARS-CoV-2 infection history to influence immunity to subsequent SARS-CoV-2 infection through a process called "immuno-imprinting" also applies to the numerous sub-variants of Omicron, including BA.4 and BA.5.
"Immunoblotting" of an early alpha variant of infection (Alpha, B.1.1.7) resulted in a decrease in the persistence of binding antibodies to Omicron.
Danny Altmann, author of the paper and professor in the Department of Immunology and Inflammation at Imperial College London, said: "We found that the Omicron variant is far from being a natural, benign booster for vaccine immunity as you might have previously thought, but rather a particularly stealthy immune escapees."
In those who received three doses of the vaccine and had no prior infection with 2019-nCoV, Omicron infection provided immune boosting to previous variants (Alpha, Beta, Gamma, Delta, and the original ancestral strain), but not to Omic Rong itself has less immunity. Those infected during the first wave of the pandemic, and those who later re-infected Omicron, had no boost.
The findings may help understand why breakthrough infections and superinfections are common among Omicron mutants. However, the study highlights that vaccination continues to provide protection against severe illness and death.
Previous analysis has suggested that even if antibodies against Omicron are poorly recognized, the body's T-cell immunity may be ready to fill in the gaps for effective protection. However, the study showed that in those infected with Omicron, their T cells had poor recognition of the Omicron spike antigen.
Corresponding author of the paper, Professor Rosemary Boyton from the Department of Infectious Diseases at Imperial, said: "Infection with Omicron does not effectively increase immunity to future re-infection with Omicron."
Altmann said, "Not only does Omicron break through vaccine defenses, but it appears to leave very little of the signature we expect on the immune system, which is more stealthy than previous mutants, and the immune system doesn't seem to remember it. "
With the Omicron variant BA.5 accounting for 70% of the population in Israel, the daily number of new cases in Israel has once again exceeded 10,000. In late May, the daily increase in Israel dropped to less than 2,000 at one point.
On June 19, local time, Israel reported that 10,202 people tested positive for the new crown nucleic acid, and the positive detection rate reached 27.9%.
Israel's new crown hospitalizations
BA.5 not only has stronger transmission speed and immune escape ability, but also can repeat infection, and its replication ability is stronger in human alveolar epithelial cells, which means that it is more pathogenic. At present, 170 of Israel's new crown patients are seriously ill, an increase of 95.4% from a week ago.Nachman Ash, director general of the Israeli Ministry of Health, said on June 19 that a new wave of infections may have arrived. Nachman Ash pointed out that in the early stages of the new wave, the Ministry of Health does not intend to impose broad restrictions on large gatherings as before. However, the Ministry of Health is considering reintroducing the mask-wearing rule in enclosed public spaces.
With BA.5 gaining ground in Israel, Israeli experts say the possibility of including a fifth shot for the elderly and immunocompromised should be considered.
In fact, the BA.4 and BA.5 mutant strains under Omicron are also emerging in the United States, setting off a new wave of infection.
The latest data from the US Centers for Disease Control and Prevention shows that as of June 11, the combined BA.4 and BA.5 accounted for 21.6% in the United States. On May 7, the merger of BA.4 and BA.5 accounted for only 1% in the United States. This means that in 35 days, the combined share of BA.4 and BA.5 has soared by 21 times. Among them, BA.4 accounted for 8.3%, and BA.5 accounted for 13.3%.
The European Centers for Disease Control and Prevention recently said that BA.4 and BA.5 spread faster than other Omicron variants and could lead to more hospitalizations and deaths.
BA.4 and BA.5 have a key mutation in the spike protein: L452R. The L452 site mutation is the spike protein mutation site that Omicron BA.1 and BA.2 mutant strains do not have, but Delta has. The spike protein plays a key role in the entry of the new coronavirus into human cells: it can bind to the ACE2 receptor of human cells and invade across the cell membrane. target.
At present, BA.4 and BA.5 have become the dominant variants in Portugal, although the vaccination rate in Portugal exceeds 85%, and it has just experienced a large number of Omicron BA.1 and BA.2 from the end of 2021 to the beginning of 2022. Infection, a new wave of infection still appeared in Portugal, and the positive detection rate was as high as 50.63%. The number of new deaths has also returned to the level at the peak of Omicron infection in January-February 2022.
Further reading: BA.4/5 replicates efficiently in human alveolar epithelial cells
The pathogenicity study of BA.4/5 was previously jointly published on the medical preprint website bioRxiv by 27 research institutes including the University of Tokyo, Kyoto University, Hokkaido University, Kyushu University, Kobe University, and Israel's Weizmann Institute of Science. Heavy research shows that the replication efficiency in human alveolar epithelial cells is higher than that of BA.2, especially BA.4 and BA.5 have stronger cell fusion ability in alveolar epithelial cells than BA.2.
In order to test the replication ability of many mutant strains of Omicron in human alveolar epithelial cells, the research team prepared a chimeric recombinant SARS-CoV-2 virus with L452R mutation through reverse genetics. The experiments showed that BA.4, The plaques formed by BA.5 infection of human alveolar epithelial cells were larger than those formed by BA.2 infection. The researchers also found through experiments that BA.4 and BA.5 were much more efficient than BA.2 in replicating human iPSC-derived alveolar epithelial cells.
Further reading: Breakthrough infection and superinfection of Omikron
The new coronavirus Omicron variant has swept the world, infecting hundreds of millions of people. Because the symptoms caused by Omicron are lighter than Delta, and natural infection can bring certain immunity, some voices believe that the Omicron variant is a natural booster. However, the latest research reveals that the effect may be the opposite: infection with the Omicron variant after vaccination may not necessarily lead to a boost of immunity, and may also weaken the immunity to the new variant later.
The above conclusions come from a recent heavyweight study published in the international authoritative academic journal "Science", "Immune boosting by B.1.1.529 (Immune boosting by B.1.1.529 (Immune boosting by B.1.1.529) Omicron) depends on previous SARS-CoV-2 exposure).
The study, led by researchers at Imperial College London in the UK, looked at how complex patterns of population immunity following vaccination and previous infection influence people's future protection against SARS-CoV-2.The official website of Imperial College London stated that the study found that the immunity brought by infection with Omicron is very poor in response to the natural immunity enhancement provided by re-infection of Omicron itself. The same goes for people infected with Omicron.
The core issue here is "Immune imprinting". In layman's terms, the body's immune pattern against the new coronavirus will be "imprinted" on the immune system through the history of infection. Each individual's immunoblot depends on the number of vaccine doses they have received and the variant they have been exposed to. This results in different immunity in different individuals in the population.
The ability of an individual's prior SARS-CoV-2 infection history to influence immunity to subsequent SARS-CoV-2 infection through a process called "immuno-imprinting" also applies to the numerous sub-variants of Omicron, including BA.4 and BA.5.
"Immunoblotting" of an early alpha variant of infection (Alpha, B.1.1.7) resulted in a decrease in the persistence of binding antibodies to Omicron.
Danny Altmann, author of the paper and professor in the Department of Immunology and Inflammation at Imperial College London, said: "We found that the Omicron variant is far from being a natural, benign booster for vaccine immunity as you might have previously thought, but rather a particularly stealthy immune escapees."
In those who received three doses of the vaccine and had no prior infection with 2019-nCoV, Omicron infection provided immune boosting to previous variants (Alpha, Beta, Gamma, Delta, and the original ancestral strain), but not to Omic Rong itself has less immunity. Those infected during the first wave of the pandemic, and those who later re-infected Omicron, had no boost.
The findings may help understand why breakthrough infections and superinfections are common among Omicron mutants. However, the study highlights that vaccination continues to provide protection against severe illness and death.
Previous analysis has suggested that even if antibodies against Omicron are poorly recognized, the body's T-cell immunity may be ready to fill in the gaps for effective protection. However, the study showed that in those infected with Omicron, their T cells had poor recognition of the Omicron spike antigen.
Corresponding author of the paper, Professor Rosemary Boyton from the Department of Infectious Diseases at Imperial, said: "Infection with Omicron does not effectively increase immunity to future re-infection with Omicron."
Altmann said, "Not only does Omicron break through vaccine defenses, but it appears to leave very little of the signature we expect on the immune system, which is more stealthy than previous mutants, and the immune system doesn't seem to remember it. "
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