Studies have shown that the "virulence" of Aumechjong is not low, delta or comeback, how to protect

The New Coronavirus Omiljung strain is generally considered to be more contagious than other variants, but the severity of the disease is lower. But a large U.S. study published on May 2 on the preprint platform Research Square said that, contrary to what had previously been thought, the "virulence" of Omikeron was not low, but as severe as the previous variant.

The impact of Omilon is not over, and its series of variants BA.1, BA.2, BA.2.12.1, BA.4 and BA.5 are setting off a new wave of outbreaks around the world. The Delta variant does not seem to be willing to be stolen by Omicron, and is quietly accumulating strength, secretly spreading, intending to "make a comeback".

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BA.2.12.1 is "gaining a foothold" in the U.S.

BA.2.12.1 is a descendant of the New Coronavirus Opichron subtype variant, BA.2, which is currently spreading rapidly in the United States.

According to US media reports, in February, two new, more contagious cases of the new coronavirus variant were detected in the northeast of the United States. They are the subtype of the Omiljun strain variant BA.2 known as BA.2.12.1 and BA.2.12.2. Before March 19, these two subtype variants accounted for only 1.5 percent of newly sequenced positive cases before spreading rapidly. Public health officials in the U.S. state of New York warn that BA.2 is at least 30 percent more transmittable than BA.1, and BA.2.12.1 is considered 23 to 27 percent more transmittal than BA.2.

During the week of April 16-23, BA.2.12.1 appeared to dominate the two variants, with the proportion of cases caused by that variant increasing from 19.6% to 28.7% in the United States. Data released by the U.S. Centers for Disease Control and Prevention (CDC) on May 3 showed that BA.2.12.1 has accounted for 36.5% of the total. In the past two weeks, this increase has been close to 100%.

CDC Director Rochelle Valensky said additional evaluations are currently underway to understand the impact of BA.2.12.1 on vaccine efficacy.

Dr Angela Blanchett, co-principal investigator in the Vaccine Therapy and Evaluation Division at the University of Rochester Medical Center in the United States, said: "BA.2 has 53 mutations, of which 29 are in spike proteins. This has led to an increased ability for the virus to spread from person to person. The BA.2.12.1 subtype also has this enhanced ability to replicate and spread from person to person ... It looks set to become the dominant variant of the United States in the coming weeks. ”

The CDC estimates that BA.2.12.2 accounts for about one-third of all cases in the United States. Currently, the number of cases of BA.2.12.2 is growing exponentially. At this rate, a sharp increase in related cases across the U.S. is expected around the next month.

BA.4 and BA.5 led to a surge in confirmed cases in South Africa

In addition to BA.2.12.1, two other variants of Ami kerong, BA.4 and BA.5, have also raised concerns.

World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus said at a press conference held in Geneva on the 4th that the two subtypes of the Omiljung strain, BA.4 and BA.5, are the reasons for the recent surge in cases in South Africa. Tedros said it was too early to determine whether the BA.4 and BA.5 subtypes would cause more severe symptoms, but they were another proof that the COVID-19 pandemic was not over.

The WHO began tracking BA.4 and BA.5 in mid-April. The WHO updates in its weekly epidemiological report that BA.4 and BA.5 "have acquired a number of additional mutations that may affect their characteristics."

Professor Tulio Oliveira, a virologist at the University of KwaZulu Natal in South Africa, wrote on Twitter that in addition to the seven provinces of South Africa, more than 20 countries, including Australia, Austria, Belgium, Israel, Denmark, France, Germany, Pakistan, the United Kingdom, the United States and Switzerland, have also detected these two subtype variants.

Oliveira noted that BA.4 and BA.5 appear to be more contagious than BA.2, two new variants that "mutate in a spectrum that allows the virus to evade immunity." They are expected to trigger a new wave of infections and may breach the protective efficacy of some vaccines. Given vaccinations and COVID-19 infections, it is estimated that more than 90% of the South African population already has some level of immunity.

The cunning Amikerjong is a "master player"

The constant emergence of these new variants shows how cunning Aumikoron is.

"In terms of ability to evade antibody activity, Omi krong is a 'master player'. It's much more efficient than all the previous variants. Shi Peiyong, a virologist at the University of Texas at Galveston, said, "It only takes a key mutation to completely change." ”

According to the National Public Radio (NPR) reported on the 4th, Shi Peiyong's team extracted blood from people infected with the original variant of Omi kerong BA.1, and checked whether the antibodies in the blood could neutralize new variants, including BA.2.12.2 in New York State or ba.4 and BA.5 in South Africa.

It was found that all people who had been infected with BA.1 had antibodies that neutralized BA.1. But compared to the new variants (BA.2.12.2, BA.4 and BA.5), neutralization efficacy declined significantly, and the extent of the decline depended heavily on whether these people were vaccinated.

The study reported that for unvaccinated people, their ability to neutralize BA.4 and BA.5 was nearly 8 times lower than their ability to fight BA.1.

Research by the team of Xie Xiaoliang, a biophysicist at Peking University, also showed that Omi kerong could evolve mutations to specifically evade immunity triggered by BA.1 infection.

Delta wants to "make a comeback"

According to the "Times of Israel" reported on the 4th, a new study in Israel shows that there is a possibility of another wave of global epidemics in the northern hemisphere this summer, and the new coronavirus Delta strain or resurgence poses a greater threat than expected.

The peer-reviewed study, based on monitoring results from sewage in Israel, revealed not only the prevalence of COVID-19 cases, but also their variants. Studies have shown that even at high levels of the Olmirkron strain, the Delta strain is secretly spreading.

After monitoring the patterns of both variants, the researchers concluded that Omexjong and its sub-variants may soon be gone, but Delta has shown such resilience that it is likely to reappear.

"In this study, we found that even when TheOmexron reached its highest level in the wastewater, Delta continued to circulate." Ariel Kushmaro, a biologist at Ben-Gurion University in Israel, said: "Our model shows that even though Aomi Kerong is dying, Delta has survived and is likely to 'make a comeback'." ”

Kushmaro and colleagues wrote in a research paper published in the journal Holistic Environmental Science that, based on analytical models, levels of Omikeron are expected to decrease until they are eliminated, while Delta will continue to maintain its stealth cycle until another wave is triggered. If this becomes a reality, the aforementioned hidden cycle could lead to a resurgence of delta pathogenic waves, or the emergence of new threatening mutant strains.

Optimal protection remains vaccination and good public measures

"Breakthrough cases of vaccination will be better." Siegel of the African Institute of Health said that for those who were vaccinated, the neutralization capacity against BA.4 and BA.5 was only 3 times lower compared to the effectiveness against BA.1. These people are also more capable of neutralizing BA.1. Thus, they end up having an average neutralizing potency of the new variant 5 times compared to people who were not vaccinated before infection.

Tedros insisted on the 4th: "The best way to protect people is still to get vaccinated, but also to take proven public health and social measures." Shi Peiyong also said: "The data shows time and time again that vaccines still have huge benefits. ”

Since the beginning of the outbreak, the WHO has officially recorded more than 6.2 million deaths from COVID-19 worldwide, but the actual number of deaths is much higher. The number of newly reported cases and deaths worldwide is declining and has now fallen to its lowest level since March 2020. But the WHO warns that the reduction in the number of cases worldwide could be the result of a sharp cut in viral testing.

Tedros said: "These trends, while welcome, do not tell the whole story. "He noted that in the Americas and Africa, reported cases are on the rise, driven by the Semikjungya variant." Many countries are largely blind to how the virus mutates," Tedros warned, "and we don't know what's going to happen next." ”

Tedros stressed that the discovery of the BA.4 and BA.5 subtypes is due to the fact that South Africa is still insisting on vital gene sequencing, which many other countries have stopped. The results of the South African study show that "viral testing and gene sequencing remain absolutely important matters".

Source: Science and Technology Daily