美国疾病控制与预防中心（CDC）专家组于周四召开会议，讨论是否调整乙型肝炎疫苗的推荐新生儿接种剂量。

公共医保计划可能不再被强制要求覆盖该疫苗，这将导致数百万家庭无法获得新生儿接种服务。

该疾病通常由母亲或照护者传染给婴儿，可能导致患者在日后罹患肝癌或肝硬化。

美国疾病控制与预防中心的疫苗咨询委员会周五即将投票决定是否取消乙肝疫苗的出生剂量建议。若通过，这将成为该机构自6月被卫生与公众服务部部长小罗伯特·F·肯尼迪改组以来最具争议性的决定。

乙肝疫苗长期以来一直是反疫苗人士的主要攻击目标。然而，即便是肯尼迪亲自挑选的免疫实践咨询委员会，要改变这项延续数十年的接种建议也举步维艰。

原定于9月举行的投票因成员间激烈分歧而搁置，周四的争执屡屡升级为高声争吵。

“我们正在试图评估一个不断变化的目标，”约瑟夫·R·希贝恩博士在会议期间表示。他是该提案最强烈的反对者之一。

尽管现行建议的变更不会禁止新生儿接种疫苗，但医疗补助（Medicaid）和其他公共医疗保险计划将不再被要求承担其费用，这将使数百万贫困家庭无法获得新生儿首剂疫苗，并给其他许多家庭带来接种困难。

与百日咳、水痘等大多数可通过疫苗预防的疾病不同，乙肝通常无明显症状，往往悄无声息地传播直至中年。此时，每四名感染者中便有一人会发展为肝癌或肝硬化。

新泽西州库珀曼巴纳巴斯医学中心病毒性肝炎项目及亚洲健康中心医疗主任、同时身为患者的苏王博士表示："这是美国死亡率最高的癌症之一。我们给患者的平均预期寿命仅为六个月。"

当前疫苗指导方针的反对者——其中包括肯尼迪、卫生局局长提名人凯西·米恩斯以及前总统特朗普——将这种病毒描述为高风险“成人”行为（如性行为和静脉注射吸毒）所导致的结果。

特朗普在9月的白宫记者会上表示："乙肝可通过性接触传播，没有理由让刚出生的婴儿感染乙肝。"

但专家表示，大多数人并非通过这种方式感染该疾病。

乙肝基金会主席查里·科恩博士表示：“乙肝病毒主要通过母婴传播。”

大多数受感染的母亲是移民——尤其是来自菲律宾、中国和越南的移民——这使得新生儿疫苗接种成为许多加州家庭的当务之急。

对一些政府官员和专家小组成员而言，该疾病在移民社区的高流行率成为了讨论焦点。

“房间里的大象是移民问题——多年来，我们一直面临非法移民的困扰，大量来自高流行国家的无证人员涌入。”伊芙琳·格里芬博士表示，她是专家组中最直言不讳支持这一变革的人士之一。

她说：“我们成年人应该用自己的资源去解决这些问题，而不是让婴儿替我们解决。”

格里芬（Griffin）等反对当前疫苗接种计划的人士认为，对所有人进行接种会给非移民家庭的健康新生儿带来不公平的负担，因为这些婴儿的母亲要么筛查结果为阴性，要么几乎没有该疾病的风险因素。

但专家指出，在当前美国医疗体系下，以全面产前检测和激进风险评估作为替代方案的提议并不现实。目前仅有不足85%的孕妇接受筛查——专家警告，若未来数月健康补贴取消且医疗补助计划（Medicaid）参保人数缩减，这一比例将急剧下降。

美国老龄化研究联盟的卡特琳·维尔纳·佩雷斯表示：“我们此前基于风险的疫苗接种策略失败了。在1991年转向全民接种疫苗之前，美国每年有近2万名婴幼儿感染。”

对于在子宫内或分娩过程中暴露于血源性病毒的婴儿而言，疫苗接种每延迟一分钟，传播风险就会增加。这一现实促使美国公共卫生官员将首剂疫苗接种时间从20世纪80年代的幼儿期提前至出生后24小时内，美国疾病控制与预防中心自1991年以来一直维持这一建议。

科恩表示：“[该疫苗]仅在美国就挽救了成千上万、甚至数百万人的生命。乙肝疫苗的安全性和有效性数据，比我们摄入体内的几乎所有其他物质都更为充分。”

数据显示，婴儿时期感染肝炎的人比成年后感染的人更容易发展为慢性感染，并最终致命。

由于病毒可在物体表面存活长达一周，医生和公共卫生专家强调，婴儿甚至可能通过看似微不足道的接触感染病毒。他们表示，看护者可能不知道自己患病，也不太可能接受检测，这使得新生儿接种疫苗变得更加紧迫。

“妈妈并不是婴儿身边的唯一接触者，”王女士在周四的专家小组会议上表示，她很可能从祖父母那里感染了这种疾病。“还有祖父母、看护人员和其他年幼的孩子。这基本上会让婴儿处于易感状态。”

数据显示，即便是共用指甲刀造成的小伤口，也存在感染风险。

肯尼迪及其在专家小组中的盟友反驳称，该疫苗对大多数婴儿并非必需，推迟接种可以让父母有机会参与关于是否接种以及何时接种的‘共同临床决策’。

然而，该小组至今仍难以就替代性建议达成一致。原定于周四进行的表决被推迟，部分原因是拟议的措辞在会议进行期间仍在不断修改。

希伯伦表示：“这是免疫实践咨询委员会（ACIP）大部分成员72小时内收到的第三版问题清单。”

在9月首次讨论调整新生儿疫苗接种建议时，希伯伦及其同组专家科迪·迈斯纳博士曾公开表示反对。

迈斯纳表示：“我们将在公众心中制造毫无根据的新疑虑。”

其他人则表示，这一举措还远远不够。

“我甚至看不出有什么理由要为生活在正常环境中的年幼儿童接种疫苗，”专家组成员雷采夫·莱维博士在九月表示。

专家警告称，除了限制疫苗的公共医保覆盖范围外，建议的变更还可能迫使购买私人保险的父母为获得新生儿接种剂量而应对复杂的多层授权程序。

许多人担心，这一决定可能会进一步污名化疫苗接种，因为当前许多家长仅仅由于相关建议正在审查中就拒绝接种。

农村和服务不足社区健康公平促进中心的凯拉·因塔班迪斯（Kayla Inthabandith）表示："各州和医院报告称，乙肝疫苗接种率正在下降。甚至有些患有乙肝的母亲拒绝为新生儿接种首剂疫苗，这使她们的婴儿面临极高的感染风险。"

专家警告称，若将建议接种时间从出生第一天推迟至第二个月，可能导致每年新增1400例感染病例。

朱迪斯·施莱博士表示："即便只有一个孩子因政策调整而感染乙肝，也已是太多。我们必须确保没有任何儿童会感染乙肝病毒。"

A CDC panel met Thursday to debate changing the recommended birth dose of the hepatitis B vaccine.

Public insurance programs could no longer be required to cover the vaccine, putting a birth dose out of reach for millions of families.

The disease is typically transmitted from mothers or caregivers to infants, leading to liver cancer or cirrhosis later in life.

A vaccine advisory panel for the Centers for Disease Control and Prevention was poised to vote Friday on whether to scrap the recommended birth dose of the hepatitis B vaccine, a move that would be the bodys most controversial decision since it was overhauled by Health and Human Services Secretary Robert F. Kennedy Jr in June.

The hep B shot has long been a top target for vaccine opponents. But changing the decades-old recommendation has proved thorny even for Kennedys hand-picked Advisory Committee on Immunization Practices.

A planned vote in September was tabled after fierce disagreement among members, whose bickering Thursday repeatedly devolved into shouting.

Were trying to evaluate a moving target, Dr. Joseph R. Hibbeln, one of the moves strongest opponents, said during the meeting.

Although a change in the current recommendation would not bar newborns from receiving the vaccine, Medicaid and other public insurance programs would no longer be required to cover it, putting a birth dose out of reach for millions of poor families and complicating access for many others.

Unlike most vaccine-preventable diseases, such as whooping cough and chickenpox, hepatitis B is typically asymptomatic, often spreading silently until midlife, when 1 in 4 infected people develop liver cancer or cirrhosis.

Its one of the cancers with the highest mortality in the U.S., said Dr. Su Wang, medical director of Viral Hepatitis Programs and the Center for Asian Health at the Cooperman Barnabas Medical Center in New Jersey, who lives with the disease. The life expectancy we give people is six months on average.

Opponents of the current vaccine guidance among them, Kennedy, surgeon general nominee Casey Means and President Trump characterize the virus as the result of high-risk adult behavior, including sex and IV drug use.

Hepatitis B is sexually transmitted, Trump said at a White House press conference in September. Theres no reason to give a baby thats almost just born hepatitis B.

But experts say thats not how most people get the disease.

Its primarily transmitted mother to child, said Dr. Chari Cohen, president of the Hepatitis B Foundation.

A majority of infected mothers are immigrants particularly from the Philippines, China and Vietnam making birth-dose vaccination an urgent priority for many California families.

For some administration officials and panel members, the diseases prevalence in immigrant communities is a talking point.

The elephant in the room is immigration we have had years of illegal immigration, undocumented people coming from higher-endemicity countries, said Dr. Evelyn Griffin, one of the panels most vocal proponents of the change.

We have problems adults need to solve with our resources there, rather than asking babies to solve this problem for us, she said.

Griffin and other opponents of the current vaccine schedule say inoculating everyone places an unfair burden on healthy newborns from nonimmigrant families whose mothers have either screened negative or have few risk factors for the disease.

But experts say the proposed alternative of universal prenatal testing and aggressive risk assessment is unrealistic in the current American healthcare system. Today, fewer than 85% of mothers are screened a number experts say will fall sharply if health subsidies disappear and Medicaid enrollment is cut in coming months.

Our previous risk-based vaccination strategy failed, said Katrin Werner Perez of the Alliance for Aging Research. Prior to the 1991 change to universal vaccination, nearly 20,000 babies and children were infected annually in the U.S.

For babies exposed to the blood-borne virus in utero or during delivery, every minute the shot is delayed heightens the risk of transmission. That reality prompted American public health officials to bump the first dose from early childhood, when it was given in the 1980s, to the first 24 hours of life, a recommendation the CDC has maintained since 1991.

[The vaccine] saved thousands, if not millions of lives just in the U.S., Cohen said. Theres more safety and efficacy data on the hepatitis B vaccine than just about anything else we put into our bodies.

Those who catch hepatitis as infants are far more likely than those who get it as adults to develop chronic and ultimately fatal infections, data show.

Because the virus can live on surfaces for up to a week, doctors and public health experts stress that babies can contract it even from seemingly trivial exposures. Caregivers might not know they have the disease, and are unlikely to be tested, making the birth dose more urgent, they said.

Mom is not the only person around the baby, said Wang, who told the panel on Thursday she likely acquired the disease from her grandparents. Theres grandparents, caregivers, other young children. Youre basically leaving that baby vulnerable.

Even a small cut from shared nail clippers risks infection, data show.

Kennedy and his allies on the panel counter that the vaccine is unnecessary for most infants, and that delaying it would offer parents the opportunity to participate in shared clinical decision-making about whether and when to vaccinate.

Still, the panel has so far struggled to coalesce around an alternative recommendation. A planned vote Thursday was tabled in part because proposed language remained in flux even as the meeting was underway.

This is the third version of the questions that most of the ACIP have received in 72 hours, Hibbeln said.

Hibbeln and fellow panelist Dr. Cody Meissner were vocal opponents of a change to the birth-dose recommendation when it was first debated in September.

We will be creating new doubts in the mind of the public that are not justified, Meissner said.

Others said the move would not go far enough.

I dont see even where is the argument to vaccinate younger children at all that live in a normal environment, panelist Dr. Retsef Levi said in September.

In addition to limiting public coverage for the vaccine, a change to the recommendation could also force privately insured parents to navigate layers of complex authorizations in order to access a birth dose, experts warned.

Many feared the decision could further stigmatize the shot in a moment when many parents are refusing it simply because the recommendation is under review.

States and hospitals are reporting declines in hepatitis B vaccination, said Kayla Inthabandith of the Center for Advancing Health Equity in Rural and Underserved Communities. Even some mothers living with hepatitis B are refusing the birth dose, putting their own infants at the highest risk of infection.

Moving the recommendation from the first day of life to the second month could lead to 1,400 new infections a year, experts warned.

Any child who gets a hepatitis B infection because we change policy is one too many, said Dr. Judith Shlay. I want us to make sure we never have any child get hepatitis B infection.