A new wave of infections is on the way
The global epidemic situation is further complicated by the more contagious NIV mutant strains, Omicron subtype BA.4 and BA.5.Israel, which has the highest number of vaccinations per capita in the world, is once again facing a new round of outbreaks, with the Omicron variant BA.5 becoming the most mainstream strain. Data disclosed by the Israeli Ministry of Health showed that 13,929 new cases of the new crown were added on June 20, with a positive detection rate of 27.9%, while in late May this year, the average daily addition in Israel was once reduced to less than 2,000 cases. Salman Zarqa, Israel’s top official for the New Coronavirus response, said that nearly 50 percent of New Coronavirus infected people carry the Omicron BA.5 variant and hospitalizations are increasing. Meaning that the Omicron variant strain BA.5 has fully spread locally. In response, Nachman Ashe, director-general of Israel’s Ministry of Health, warned that a new wave of infections may have arrived in Israel, and that the Ministry of Health has not yet planned to impose broad restrictions on large gatherings in the early stages of this wave, but that the Ministry is considering reimposing the requirement to wear masks in enclosed public spaces. And, with BA.5 taking over in Israel, Israeli experts say the possibility of including the fifth dose of vaccine for the elderly and immunocompromised people should be considered.
Meanwhile, the outbreak situation in the UK is not encouraging. On June 20, local time, the British Medical Journal (BMJ) published an article titled “Omicron subvariant is driving a new wave of infections in the UK”. The data therein show that the number of confirmed cases of New Crown in the UK jumped 43% last week from a year earlier, and according to the New Crown Infection Survey, it is estimated that 1 in 50 people in England was positive for New Crown in the week of June 11, and in Scotland, where the infection is more severe, roughly 1 in 30 people can be tested positive. In addition, the latest data disclosed by NHS England shows that the number of cases testing positive for neo-crown among hospital admissions to the English health system jumped 31% in a week as of June 16. The UK’s New Coronas Actuarial Response Team warned that the current rate of increase in new coronas admissions is faster than it was during the BA.2 outbreak in March and that this is something to worry about. In Portugal, BA.5 became the main endemic strain there back in May of this year and now accounts for 90% of new cases in the country. The European CDC reports that Austria, Belgium, Denmark, France, Germany, Italy, the Netherlands, Spain, Sweden, and Ireland have all seen a rise in BA.4 and BA.5 infections. In addition to Europe and the U.S., Asian regions are also at greater risk. On June 20, Singapore’s Health Minister Yikang Wang clearly warned that the country is likely to face a new wave of BA.4 and BA.5 outbreaks starting in July-August this year; Indonesia’s Health Minister Sadikin also warned that BA.4 and BA.5 will trigger a new wave of outbreaks this summer. According to media reports, the positive test rate in the Indian city of Mumbai was as high as 13.88%, nearly three times the Indian average, and the number of hospitalized cases reported in the past 10 days has increased dramatically by 187%.
On June 21, Taiwan’s “China Times News Network” reported that Taiwan’s border has once again intercepted 17 cases of overseas importation of BA.4 and BA.5, mainly from the U.S. So far, Taiwan’s border has intercepted a total of 65 cases of BA.4 and BA.5. Up to now, a total of 65 cases of BA.4 and BA.5 have been intercepted at the Taiwan border. Omicron BA.4 and BA.5 will replace BA.2.12.1 as the most mainstream strains in the world, which is gradually becoming a consensus.
Recently, three top-ranking journals have published consistent serological studies on Omicron BA.4 and BA.5, revealing ideas on how to deal with this new strain.
Among them, Cell published an article from the Screaton group at the University of Oxford, which comprehensively reported the serological characteristics of BA.4 and BA.5. This article concluded that BA.4 and BA.5 had more significant immune escape to the sera of 3 doses of vaccine recipients, and the neutralizing activity was only 1/3 of that of BA.1; BA.4 and BA.5 added L452R and F486V Two mutations were added to BA.4 and BA.5, which is one of the main reasons for having more significant immune escape.
On June 15, 2022, the New England Journal of Medicine (NEJM) published the serologic profile of BA.4/5 by the team of virologist Shanlv Liu at The Ohio State University, whose main findings were that the neutralizing antibody titers were 52 for BA.1, 39 for BA.2, and only 37 for BA.4/5 for 2 doses of vaccination; 976 for BA.1, 933 for BA.2 was 933 and to BA.4/5 was 647.
On June 17, 2022, Nature published a study by Xiaoliang Xie’s team at Peking University, which showed that the new subtypes of Omicron BA.4 and BA.5 presented stronger immune escape and showed significant neutralizing escape in plasma of recovered Omicron BA.1-infected patients.
The above three topical articles consistently confirmed that Omicron BA.4 and BA.5 subtypes showed stronger immune escape.
In addition, for the pathogenicity of BA.4 and BA.5, a preprinted study published in BioRxiv at the end of May by researchers from Kumamoto University, the University of Tokyo, and the Tokyo Institute of Public Health in Japan showed that hamsters infected with BA.4 and BA.5 had greater viral loads in their lungs in live animal experiments. The researchers concluded that this result shows that for hamsters, virus spread in the lungs is higher after infection with BA.4 and BA.5 than with other Omicron variants. The study has not been peer-reviewed.
Based on the findings of the current study, analysts believe that the main strategies to prevent Omicron BA.4 and BA.5 subtypes are to continue to wear good masks and reduce unnecessary indoor gatherings; physical isolation from the virus is still an effective method; vaccination with a full 3 doses of New Crown vaccine is still the most effective way to prevent severe disease, and to use rapid antigen detection kits at the first sign of relevant symptoms and go to a testing site if necessary for Nucleic acid testing.
By Josie
