JN.1 will bring more COVID-19 infections, but won't seriously worsen current situation: experts

The latest COVID-19 variant JN.1 is spreading around the world, leading to growing concerns in Chinese society, following a recent severe wave of respiratory infections. Chinese experts estimate that the variant will cause more infections in the near future, but it is not likely to seriously worsen the current situation.

Named JN.1, this variant was first identified in Luxembourg, before spreading to the UK, Iceland, France, and the US.

By the end of October, JN.1 made up less than 0.1 percent of SARS-CoV-2 viruses circulating in the US. But as of December 8, 2023, the ratio climbed to 15-29 percent, according to the US Centers for Disease Control and Prevention (CDC).

The US estimated that COVID-19 infections are likely to increase in the next month.

Data in the UK also suggested that the variant is spreading more than every other known strain, making up one in 13 cases in England last month.

The JN.1 variant is part of the BA.2.86 variant of the SARS-CoV-2 virus, with an additional L455S mutation in the RBD region. Early studies have shown that BA.2.86 has similar immune escape capabilities as the XBB variants. However, recent research has found that the L455S mutation in the JN.1 variant further enhances its immune evasion ability, allowing it to partially escape the humoral immune response induced by XBB.1.5 breakthrough infections, Lu Hongzhou, head of the Third People's Hospital of Shenzhen, told the Global Times on Tuesday.

According to current research, BA.2.86, first identified in August 2023, carries more than 30 mutations in the spike (S) protein compared to the XBB and BA.2 variants, indicating high potential for immune evasion.

Another name of JN.1 is BA.2.86.1.1 and there is only a single change between JN.1 and BA.2.86 in the spike protein, according to current research.

A recent study by Japanese scientists published on bioRxiv on December 8 evaluated the virological characteristics of the omicron subvariant JN.1, which shows robust immune evasion ability compared to other variants. This could be due to the acquisition of the L455S mutation in the spike protein. The study noted that JN.1 has the ability to become a dominant variant worldwide in the future.

But so far, there is no evidence that JN.1 presents an increased risk to public health compared to other variants, according to the US CDC.

Currently, the XBB variant of COVID-19 is still the main strain of the local infections in China. Many clinical doctors told the media that they had witnessed an increase in COVID-19 infections recently and they predicted this wave of infections will last till late January 2024 with mortality and severe illness rates likely to increase.

"Since December last year, SARS-CoV-2 has been co-circulating with other respiratory pathogens in China, leading to many domestic residents in the country having experienced two or even three infections. Existing research data indicates that such infection experiences can generate strong and broad-spectrum neutralizing antibodies against different subvariants of Omicron. Furthermore, although JN.1 has increased immune escape ability, there is currently no evidence to suggest an increase in the pathogenicity of the JN.1 variant," Lu explained.

"Therefore, we speculate that the future prevalence of JN.1 in our country may temporarily increase the number of COVID-19 patients and burden hospitals, but it will not significantly worsen the ongoing respiratory disease outbreaks," he said.

Lu reiterated the necessity of vaccination as it is an effective method to improve the speed and intensity of antibody production, providing better protection for the body.

Authorities in multiple cities across China such as Shanghai and Tianjin have sent notices to advise local residents to take COVID-19 vaccines targeting the XBB variant, urging eligible individuals to get the vaccine in a timely manner to enhance their protection against the virus.