While Americans increasingly shed masks, forgo COVID-19 boosters, and embrace post-pandemic normalcy, a viral specter is spreading across Asia — and it’s beginning to show up in the U.S. A new subvariant of the SARS-CoV-2 virus, which causes COVID, is quickly gaining prominence and threatening to ignite a summer wave of infections. This is occurring just as U.S. policymakers are backing away from aggressive public health protections.
The new variant, NB.1.8.1, part of the JN.1 lineage of Omicron variants of SARS-CoV-2 , has already been detected in U.S. travelers through airport screening and is now circulating in California wastewater, including in the Los Angeles and San Francisco Bay areas. While still a minor player among global variants, its penetrance is rising -- from just 2.5% of global sequences in early April to 10.7% by the end of the month, a concerning exponential four-fold increase. The World Health Organization (WHO) upgraded NB.1.8.1 to a “variant under monitoring” last month.
The U.S. is currently dominated by LP.8.1, a variant on the decline and targeted by the updated fall boosters from Moderna and Pfizer. But NB.1.8.1 may have a competitive edge, because it appears to be more capable of evading immune defenses than LP.8.1: Preliminary data demonstrate enhanced resistance to immunity from prior infection or vaccination, although it appears not to cause more severe illness than its antecedents.
A Perfect Storm for a Summer Surge
Other parts of the world offer an unsettling preview of what may be coming. In Taiwan, where NB.1.8.1 has been driving a significant uptick in hospitalizations and deaths, public health officials are reporting severe testing kit shortages and warning that the current wave may not peak for another month or more.
In Hong Kong, Japan, and parts of Southeast Asia, the same variant is spreading rapidly, boosting the numbers of cases and straining hospital systems already burdened by overlapping flu and respiratory syncytial virus (RSV) outbreaks. In California, early indicators like wastewater sampling and test positivity are ticking upward. In Los Angeles County, levels of SARS-CoV-2 in wastewater have risen by 6% in recent weeks, and test positivity has edged up to 3.5%.
Historically, the U.S. has experienced both winter and summer surges in COVID cases. This past winter, the wave was relatively mild, leaving a large fraction of the population with waning immunity; and since vaccination rates are low, we are vulnerable to a summer spike of COVID infections.
Policy Confusion Amid Political Turbulence
In a troubling twist, the emerging threat of NB.1.8.1 comes just as the federal government is vacillating about critical vaccination guidance. Within days after HHS Secretary Robert F. Kennedy Jr. announced that the CDC would no longer recommend COVID shots for children and pregnant women, the CDC adopted a conflicting policy, updating its childhood immunization schedule to reflect that for kids ages 6 months to 17 years who are lower-risk -- that is, aren't moderately or severely immunocompromised -- the decision to vaccinate should be made via a discussion between parents and healthcare providers. It continues to recommend that higher-risk children be vaccinated.
This “shared decision-making” was described thus: "Where the parent presents with a desire for their child to be vaccinated, children 6 months and older may receive COVID-19 vaccination, informed by the clinical judgment of a healthcare provider and personal preference and circumstances." Previously, language about shared decision-making was not included and the CDC had recommended that all children 6 months and older should receive the vaccine.
The newly announced policy, which will likely be interpreted by anti-vaccine influencers as encouragement to "do your own research," is widely unpopular in the medical community. The science is clear: Pregnant women and infants are among the most vulnerable to COVID complications. “Infants under 6 months of age have the same risk of complications as the 65-and-older population in this country,” Dr. Yvonne Maldonado, a Stanford University infectious disease expert and CDC advisor, said. Studies show that vaccination during pregnancy not only protects the mother but also delivers antibodies to the fetus and breastfeeding infant. The American Academy of Pediatrics, the California Department of Public Health, and other medical organizations continue to endorse vaccination for children and pregnant women, based on decades of research and mounting evidence of safety and efficacy.
The Vaccine Mismatch
The FDA recently recommended that the next round of COVID vaccines should be monovalent and target the JN.1 lineage. Moderna and Pfizer both selected LP.8.1 as their strain of choice. But with LP.8.1 potentially on the decline and NB.1.8.1 surging, it’s unclear how well the boosters will be matched to the virus circulating later this year.
Still, experts are urging people to get vaccinated. Even mismatched vaccines have consistently reduced hospitalizations and deaths. But if NB.1.8.1 becomes dominant in the months ahead, and if vaccine uptake falters due to cost or skepticism, the U.S. could once again face a preventable wave of illnesses.
A False Sense of Security
The public’s willingness to neglect COVID protections is understandable. The emergency phase has passed, schools and businesses have reopened, and most people now see the virus as manageable. But complacency can be dangerous.
Americans' willingness to get COVID boosters has flagged, and the CDC estimates that between 30,000 and 50,000 Americans have died from COVID since October. Hundreds of thousands have been hospitalized. Among children, hospitalization rates remain highest for those under age 5, even among those with no underlying health conditions.
Variants like NB.1.8.1 may not cause more severe disease, but their high transmissibility and ability to evade immunity could translate into large case numbers and a strain on healthcare systems.
A Time for Vigilance, Not Retreat
As the U.S. faces the possibility of another COVID wave, infectious disease experts are calling for renewed vigilance. Ensuring up-to-date vaccinations and keeping testing and treatment accessible are modest measures that could save lives. But these efforts require public support — and clear, science-based leadership.
Henry I. Miller, MS, MD
Henry I. Miller, MS, MD, is the Glenn Swogger Distinguished Fellow at the American Council on Science and Health. His research focuses on public policy toward science, technology, and medicine, encompassing a number of areas, including pharmaceutical development, genetic engineering, models for regulatory reform, precision medicine, and the emergence of new viral diseases. Dr. Miller served for fifteen years at the US Food and Drug Administration (FDA) in a number of posts, including as the founding director of the Office of Biotechnology.
