China's influenza activity has rapidly increased in recent weeks but remains within the expected winter range, with no novel or unknown variants being detected, health authorities said recently.

卫生部门近日表示，中国流感活动水平近几周迅速上升，但仍处于冬季预期范围内，未检测到新型或未知变异株。

Latest data from the Chinese Center for Disease Control and Prevention shows that flu levels are increasing in both northern and southern regions. This surge led to 955 reported infection clusters in the week beginning Nov 10.

中国疾病预防控制中心最新数据显示，流感疫情在南北地区均呈上升趋势。11月10日当周，全国共报告955起流感聚集性病例。

The H3N2 subtype of influenza A is currently dominant, accounting for over 99 percent of samples from flu-like cases, with the remainder being the H1N1 subtype of influenza A and the influenza B strain.

甲型流感H3N2亚型目前占主导地位，占流感样病例样本的99%以上，其余为甲型流感H1N1亚型和乙型流感病毒株。

"The nation has entered a period of rapidly increasing flu cases, with the majority of regions seeing a medium to high level of virus circulation," said Peng Zhibin, a researcher at the China CDC, at a news conference on Friday.

中国疾控中心研究员彭质斌周五在新闻发布会上表示："全国流感病例正进入快速增长期，多数地区病毒传播处于中度至高度水平。"

Peng also noted a significant rise in outbreaks at schools and nurseries, with the flu positivity rate among children and adolescents aged 5 to 14 markedly higher than in other age groups.

彭质斌还指出，学校和托儿所的疫情爆发显著增加，5至14岁儿童和青少年的流感阳性率明显高于其他年龄段。

Last winter's flu season was primarily driven by the H1N1 strain, while the current dominant strain is the H3N2 strain.

去年冬季的流感季节主要由H1N1病毒株驱动，而当前占主导地位的病毒株则是H3N2病毒株。

A specific H3N2 subclade, known as K, has also driven up infections in parts of the northern hemisphere, including the United Kingdom, Canada and Japan, fueling concerns that this signals a faster evolving or more severe virus.

一种名为K的特定H3N2亚系病毒也在北半球部分地区（包括英国、加拿大和日本）引发感染激增，这引发了人们对该病毒可能具有更快的进化速度或更强的致病性的担忧。

In response, Peng said that the flu virus is prone to minor mutations. The current flu activity still remains at the normal, seasonal epidemic level and does not indicate that the virus is becoming increasingly fierce.

对此，彭质斌回应表示流感病毒容易发生轻微变异。当前流感活动仍处于正常季节性流行水平，并不表明病毒正在变得越来越凶猛。

"So far, all detected cases are common and known pathogens, with no unknown or newly emerging pathogens," she said.

彭质斌表示：“迄今为止，所有检测到的病例均由常见且已知的病原体引起，未发现未知或新出现的病原体。”

Wang Dayan, director of the Chinese National Influenza Center, said during an earlier news conference that the composition of each year's flu vaccine is updated to best match the strains expected to circulate, including this year's dose.

中国国家流感中心主任王大燕在早前举行的新闻发布会上表示，每年流感疫苗的成分都会根据预计流行的毒株进行更新调整，今年的疫苗也不例外。

"The matching level for the H3N2 virus has improved compared to previous years, while the matches for H1N1 and influenza B are even higher," she said. "Over 95 percent of circulating strains are antigenically similar to the vaccine strains."

王大燕表示：“与往年相比，H3N2病毒的匹配水平有所提升，而H1N1和B型流感的匹配度更高，超过95%的流行毒株与疫苗毒株具有抗原相似性。”

Experts said that the optimized period to get vaccinated is before the start of the flu season, so as to reduce the possibility of severe symptoms and prevent infection clusters.

专家表示，接种疫苗的最佳时机是在流感季节开始之前，这样既能降低出现严重症状的可能性，又能防止感染聚集性病例的发生。

However, Peng said that even individuals who have already been infected can benefit from the shot, as the trivalent vaccine contains all three circulating strains and can provide protection against those they have not contracted.

不过彭质斌强调，即使已经感染过的人群也能从接种中获益，因为三价疫苗包含所有三种流行毒株，能够为未曾感染过的毒株提供保护。

Chinese Center for Disease Control and Prevention

中国疾控中心

influenza A

甲型流感

trivalent vaccine

三价疫苗