The Vaccine Intelligence Report: April 15-21

The Vaccine Intelligence Report—brought to you by Vaccinate Your Family—provides clear, fact-based updates on vaccine policy, research, and public health each week. This report is part of Viral Truths, a resource designed to cut through the noise, offering concise information to help navigate the evolving immunization landscape.

THIS WEEK AT A GLANCE

  • President Trump has nominated Dr. Erica Schwartz to lead the CDC, signaling a potential shift toward more traditional public health leadership amid ongoing instability; Trump also announced appointments for three other CDC leadership roles
  • During his testimony before three key committees last week, HHS Secretary Kennedy faced scrutiny from members of Congress over vaccine policy and measles; Kennedy is appearing before four more committees this week
  • A California bill to expand childhood immunization exemptions and a Louisiana bill to remove meningococcal school immunization requirements both failed to advance this legislative session, while lawmakers in Iowa, Maine, and New Hampshire continue to debate vaccine-related bills
  • Florida is moving to revive “medical freedom” vaccine legislation in an April special session, as the state’s vaccination rates decline and measles cases rise following a major outbreak
  • The U.S. added 49 new measles cases in the past week, as new research projects significant economic costs if vaccination rates decline further
  • Respiratory illness activity remains low overall, and new data highlight serious risks for older adults hospitalized with RSV
  • Increases in rotavirus and mpox cases are being reported, with experts emphasizing the importance of vaccination to prevent severe illness

NEED TO KNOW

Trump Nominates Erica Schwartz to Lead CDC as Agency Faces Ongoing Leadership Instability

  • Last week (Apr. 16), President Donald Trump announced his nomination of longtime federal health official and former Deputy U.S. Surgeon General, Dr. Erica Schwartz, to serve as Director of the Centers for Disease Control and Prevention (CDC).
    • Schwartz is a physician and retired U.S. Public Health Service Rear Admiral who previously served in the Navy and Coast Guard. She is widely viewed as a more traditional, science-aligned pick than some previously-considered candidates.
  • The nomination comes after a prolonged period of disruption—particularly in agency leadership—across the CDC and other Health and Human Services (HHS) agencies.
    • The Administration’s first nominee, former Rep. Dave Weldon, was withdrawn amid concerns he lacked sufficient support for Senate confirmation, and its second, Dr. Susan Monarez, was removed less than a month into her tenure after clashing with HHS leadership over issues like vaccine and staffing issues.
    • As a result, the agency has cycled through multiple leaders and interim arrangements, contributing to internal disruption and broader uncertainty about the agency’s direction.
  • In the same announcement on Truth Social, Trump also announced additional leadership appointments including: Sean Slovenski (former president of Walmart Health) as CDC Deputy Director and Chief Operating Officer; Jennifer Shuford (Texas state health commissioner) as CDC Deputy Director and Chief Medical Officer; and Sara Brenner (FDA Principal Deputy Commissioner) as Senior Counselor for Public Health to HHS Secretary Robert F. Kennedy Jr.
  • The broader policy environment further shapes the stakes of this nomination: HHS leadership has pursued significant changes to vaccine guidelines and advisory processes over the past year, but recent signals suggest the White House is seeking to avoid making vaccines a central political issue ahead of the midterm elections.
    • The selection of Schwartz seems to reflect the Administration’s effort to identify a candidate who can both secure Senate confirmation and bring some much-needed stability to the CDC.
    • That said, the choice has drawn criticism from some vaccine-skeptical voices, highlighting ongoing internal divisions, while health experts and former officials have expressed cautious optimism about the nomination, pointing to Schwartz’s experience and credibility.
  • Schwartz must now be confirmed by the Senate, where she is expected to face questions about vaccine policy, agency independence, and how she would navigate disagreements with HHS leadership over public health decisions.

Kennedy Testifies Before Congress, Draws Questions on Measles and Vaccines

  • Kennedy faced renewed congressional scrutiny last week as he appeared before multiple committees to defend the Administration’s health priorities and budget—marking his first testimony in several months.
  • Kennedy’s remarks have largely avoided vaccines, focusing instead on chronic disease, nutrition, drug pricing, and fraud—reflecting a broader shift in the Administration’s public messaging in recent months.
  • However, some members of Congress pushed him on vaccine policy and messaging, particularly on the measles outbreak and the measles, mumps, rubella (MMR) vaccine.
    • Reps. Mike Thompson (D-CA) and Madeleine Dean (D-PA) pointed to the sharp rise in measles cases in 2025 and into 2026 and declining vaccination rates, but Kennedy argued that these trends began before the current Administration.
      • Since 2000, total annual measles cases have remained under 300, with few exceptions (2014, 2018, and 2019). This ballooned to more than 2,200 cases in 2025.
      • Kindergarten MMR vaccination has steadily declined since the 2019-2020 school year (95.2%), with national coverage for 2024-2025 at 92.5%.
    • When pressed by Rep. Linda Sánchez (D-CA), Kennedy acknowledged that it was “possible, certainly” that vaccination could have prevented the death of a Texas child due to measles. He also stated that the MMR vaccine is safe and effective “for most people” and is safer than getting measles.
    • However, Kennedy reiterated claims that vaccines are not adequately tested for safety—contradicting extensive evidence from clinical trials and post-licensure monitoring demonstrating their safety.
  • Kennedy also defended the CDC’s decision to stop recommending hepatitis B vaccination for all infants at birth, claiming the vaccine “was not safety tested” and its risks are not known.
    • In December, the CDC adopted the Advisory Committee on Immunization Practices’ (ACIP) recommendation to change guidance, instead only recommending vaccination for children born to mothers who test positive for hepatitis B or whose status is unknown, and shared clinical decision-making (SCDM) for infants with mothers who test negative.
    • However, this change has been halted due to a preliminary injunction in the American Academy of Pediatrics’ (AAP) lawsuit against Kennedy while litigation proceeds. AAP and other major medical societies continue to recommend hepatitis B vaccination for all newborns.
    • Substantial evidence—including randomized trials, large national safety monitoring programs, and long-term follow-up studies—consistently affirms the safety of hepatitis B vaccination regardless of administration timing.
  • Additional hearings this week before Senate Finance and Health, Education, Labor, and Pensions (HELP) Committees could bring further scrutiny of the Administration’s vaccine policies, which remain a point of tension on Capitol Hill.

STATE POLICY SPOTLIGHT

Vaccine Exemption and School Immunization Requirement Bills Fail to Advance in California, Louisiana

  • A California bill (SB 1377) aimed at reforming the state’s medical vaccine exemption system failed to pass the Senate Health Committee on April 15.
    • The proposal would have allowed childhood immunization exemptions to carry over throughout elementary, middle, and high school. Current law requires exemptions to expire between levels of schooling.
  • Lawmakers in Louisiana voted down a bill (HB 737) that would have removed school immunization requirements for the meningococcal vaccine. The bill faced opposition from both parties, as well as from medical professionals.

Iowa, Maine, New Hampshire See Movement on Vaccine-Related Legislation

  • The Iowa House passed a bill (SF 304) on April 14 requiring parental consent for minors to receive the human papillomavirus (HPV) vaccine, adding an additional step before adolescents can be vaccinated.
    • The bill now advances to the Senate as lawmakers continue to debate parental authority and adolescent access to preventive care.
  • The governor of Maine signed two bills aimed at protecting access to vaccination: LD 2071 and LD 2146.
  • Three vaccine-related bills remain under consideration in New Hampshire.
    • HB 1719, which would remove the hepatitis B vaccine from the state’s school immunization requirements, remains under consideration in the Senate.
    • HB 1449, which would limit school vaccination clinics and require parents or guardians to be present during vaccination, has cleared a Senate committee with a unanimous recommendation and is nearing a full Senate vote.
    • HB 1584, which would require the state’s Department of Health to provide information on medical and religious vaccine exemptions, is also progressing in the Senate, but at an earlier stage than HB 1449.

Florida to Revive “Medical Freedom” Vaccine Legislation in Special Session

  • On April 15, Florida Governor Ron DeSantis postponed a planned special session on redistricting and updated its scope to include “medical freedom.” The renewed session, now set to begin April 28, signals renewed momentum for vaccine-related measures that stalled during the regular session.
  • DeSantis specifically referenced the “Medical Freedom Act” (SB 1756), which cleared the Senate during the regular session but failed to advance through the House before lawmakers adjourned.
    • The bill would have created a new “conscience” exemption from school and daycare immunization requirements, required parents to receive specified materials before a child is vaccinated, and placed a permanent ban on requirements for mRNA vaccines.
  • The renewed push comes as Florida’s childhood vaccination rates continue to decline. State kindergarten immunization coverage was about 88% in 2026, and recent reporting found vaccination rates fell again in the 2025-26 school year even as measles cases rose.
    • The state is also coming off the heels of a large measles outbreak centered in Collier County, where 107 cases have been reported this year. Statewide, Florida’s 2026 total has reached 145 cases.

OUTBREAK OUTLOOK

News on respiratory virus season, measles, pertussis, and other vaccine-preventable and infectious disease outbreaks.

Measles Cases Plateau in Some States, but Utah Outbreak Continues to Drive U.S. Total

  • As of April 17, the U.S. has reported 1,851 measles cases in 2026—an increase of 49 new cases in the last week.
    • Arizona has added 7 new measles cases since April 14—bringing its total to 85 cases this year.
    • California has reported 7 measles cases this month, bringing the state’s 2026 total to 43 cases—the highest number of cases in California in seven years.
    • South Carolina reported one new measles case last week, related to international travel and not linked to the Upstate outbreak. The state’s total since last July is 1,001.
    • Utah has reported 5 new measles cases from April 14-21, bringing its total to 410 this year.
    • Additional 2026 cases have been confirmed in Colorado (16), New Mexico (16), Texas (180), and Washington (37).
  • New research estimates that measles outbreaks cost the U.S. $244.2 million in 2025, and that costs could rise substantially if MMR vaccination rates continue to decline.
    • The study found that an annual reduction of 1% in childhood vaccine coverage could result in costs up to $7.8 billion over five years, with costs per case varying widely by county.
    • Researchers note that modest reductions in vaccine coverage generate nonlinear increases in cases and hospitalizations, leading to substantial costs across outbreak response, medical costs, and productivity losses.

Respiratory Illness Activity Low; Risk of Serious Outcomes High for Older Adults with RSV

  • National respiratory illness activity remains at very low levels.
    • Flu activity continues to decline. All states are reporting low or minimal activity levels, down from four states with moderate activity last week.
      • Even as activity declines, four additional pediatric flu deaths were reported in the past week, bringing the seasonal total to 143.
    • Unchanged from last week, Covid activity remains low, and hospitalizations continue to decrease.
    • Respiratory syncytial virus (RSV) activity is still elevated but has peaked in many regions.
      • Wastewater data indicate high activity in Massachusetts, South Dakota, West Virginia, and Wyoming.
  • As RSV spread continues into late April, a new study underscores the severity of infection for older adults.
    • Researchers found that severe outcomes including admission to the intensive care unit (ICU), vasopressor support (using medication to raise blood pressure), mechanical ventilation, and abnormally fast heart rate were common for older adults hospitalized for RSV.

Increases in Rotavirus and Mpox Cases Reported

  • Wastewater data show that rotavirus activity has been elevated across the country since January.
    • Rotavirus is highly contagious and a major cause of severe illness among babies and young children in the U.S.
    • Experts warn that declining rotavirus vaccination rates will continue to cause increases in hospitalizations and deaths and urge parents to protect their children through vaccination.
    • There are two rotavirus vaccines currently licensed for infants in the U.S. Children should get their first dose before age 15 weeks and complete all doses before age 8 months.
  • One case of clade I mpox was reported in San Francisco last week (Apr. 14), prompting experts to urge vaccination.
    • Cases of clade I mpox are rare in the U.S.—the CDC has reported 16 total cases between November 2024 and March 2026, all linked to international travel.
    • Clade II cases circulate at low levels in several countries including the U.S., where cases have hovered around 200 or fewer per month since October 2024.
    • Health officials encourage anyone at risk of contracting mpox to receive both doses of the mpox vaccine, which protects against both clade I and II.

REALITY CHECK

These fact checks respond to several recent claims made by different groups and individuals.

CLAIM: We shouldn’t vaccinate newborn infants against hepatitis B unless their mother tests positive for the disease. We test all mothers for hepatitis B, and babies born to mothers who test negative aren’t at risk.

  • REALITY: Hepatitis B vaccination at birth is the most effective method of preventing transmission and has led to 99% decrease in childhood infections since 1991. Delaying vaccination leaves infants vulnerable to undiagnosed maternal infection and exposure to hepatitis B after birth.
    • Children infected in the first year of life had a 90% chance of developing chronic hepatitis B, and 25% of those who develop a chronic infection will die from the disease.
  • While current U.S. guidelines recommend hepatitis B screening for pregnant women, many people slip through the cracks.
    • Up to 18% of pregnant women do not receive hepatitis B testing during pregnancy, and only 35% of women who test positive receive the recommended follow-up testing and care.
  • Further, unvaccinated newborns are at risk of hepatitis B transmission from household, daycare, and other contacts. One study found that 21% of children with evidence of infection had no household members who were hepatitis B-positive.
  • Moreover, ample evidence shows that the hepatitis B vaccine is safe for infants and provides long-lasting protection. Randomized trials, large national safety monitoring programs, and long-term follow-up consistently affirm the vaccine’s short and long-term safety.
    • There is no increased risk of any adverse event in vaccinating at birth compared to delayed administration.
  • Overall, hepatitis B vaccination at birth provides a critical safety net that protects all infants from potential life-long conditions, regardless of their mothers’ health status.

CLAIM: The U.S. is handling measles better than other countries and has been highly effective at limiting its spread.

  • REALITY: Unfortunately, the U.S. is not outperforming other countries in its control of measles, and several key measures show that its ability to prevent measles outbreaks has weakened in recent years.
  • Measles cases in the U.S. have remained low for decades largely due to strong vaccination rates, though declining uptake in recent years is beginning to reverse that progress.
    • National kindergarten measles vaccination rates declined from 95.2% in the 2019-2020 school year to 92.5% in 2024-2025 (and this percentage is even lower in some regions), falling below the ~95% threshold needed to prevent outbreaks.
    • As vaccination rates have dropped, cases have risen—the U.S. has experienced its largest surge in decades, and recent case counts for 2026 are already on track to eclipse last year’s total.
  • While it’s true that some countries report larger outbreaks in absolute numbers compared to what the U.S. has reported in recent years, these comparisons can be misleading—historically, many of the largest outbreaks have occurred in lower-resource settings with less consistent access to vaccines and limited healthcare infrastructure.
  • Low measles incidence through high vaccination coverage is standard among peer, high-income nations. The U.S.’s impending loss of its measles elimination status following declining vaccination rates and historic case counts in 2025 and 2026 demonstrates a decreasing ability to control the spread of measles in recent years.
    • According to the most recent data from the World Bank, 83 countries have higher measles vaccination rates than the U.S., and 67 countries have rates that meet or exceed the 95% threshold required to prevent community transmission.
    • In 2025, the U.S. reported some of the highest rates of measles seen in decades. Meanwhile, many countries in Europe and Central Asia saw a significant drop in cases thanks to immunization campaigns and outbreak response measures.
  • Ultimately, while measles persists as a global challenge, the U.S. is falling behind its peers in preventing its spread—and growing more vulnerable to outbreaks as coverage continues to decline.

CLAIM: Infectious diseases aren’t really that dangerous, and it’s very unlikely that they will lead to serious issues in people who are healthy.

  • REALITY: While it’s true that some conditions can raise the risk of complications, healthy people can and do get seriously ill, hospitalized, disabled, and killed by infectious diseases.
  • Take flu for instance: according to one analysis, during the 2024-2025 flu season—at the time of evaluation—280 pediatric deaths were reported to the CDC, and only 56% of these deaths were among children who had an underlying medical condition.
    • Severe complications—even if they don’t always result in death—also occur in healthy populations. During the same season, 109 cases of pediatric encephalopathy (a serious brain condition that can lead to seizures, swelling and long-term brain damage) were reported; 55% of cases occurred in previously healthy children, 74% required ICU care, and 19% died.
  • We’ve also seen the impacts of measles in recent years, which can cause serious illness even in healthy children. About 1 in 5 unvaccinated people who get measles in the U.S. are hospitalized, roughly 1 in 1,000 develop brain swelling that can lead to permanent damage, and 1-3 out of 1,000 people with measles will die—even with the best care.
  • Some infectious diseases can also progress rapidly and unpredictably. Meningococcal disease—which can affect otherwise healthy adolescents and young adults—can become life-threatening within hours, which is why routine vaccination is recommended for all teens, not just those at high-risk.
  • Even beyond children, vaccine-preventable diseases continue to cause significant illness and death in the U.S. each year, including among populations that are otherwise healthy. For example:
    • Seasonal flu causes an estimated 6,300-52,000 deaths and hundreds of thousands of hospitalizations annually in the U.S.
    • Meningococcal disease kills 1 in 6 of those infected with invasive meningococcal disease, even with treatment, and 1 in 5 survivors will suffer from serious complications such as limb loss, hearing loss, or brain damage.
    • Pneumococcal disease—a leading cause of bacterial pneumonia, bloodstream infections, and meningitis—leads to more than 2 million infections and 6,000 deaths each year in the U.S.
  • Further, while not all infections are fatal, they can still cause serious complications, long-term health effects (including neurological damage, organ failure, hearing loss, and cancer) and significant—and otherwise avoidable—disruption to daily life, wellbeing, and productivity.
  • In short, being healthy does not eliminate risk—and thanks to the availability of vaccines that have been extensively studied and shown to reduce severe illness—many of these outcomes are preventable.

WHAT TO WATCH

Final Senate Hearings to Test Kennedy’s Vaccine Messaging Strategy

  • Kennedy will testify before the Senate Finance and HELP Committees today (Apr. 22), marking the final appearances in a series of seven congressional hearings tied to the Administration’s health priorities and budget.
  • The hearings come as Kennedy has largely deemphasized vaccines in public remarks, instead focusing on chronic disease and broader health system issues.
  • Lawmakers are expected to continue raising questions on measles, immunization guidance, and agency decision-making—offering further insight into how the administration balances internal pressures on vaccine policy with broader political considerations.

Kennedy Signals Plan to Reshape Preventive Care Panel

  • Kennedy said last Thursday (Apr. 16) that he plans to overhaul the U.S. Preventive Services Task Force (USPSTF), an independent advisory body that determines which preventive services insurers must cover under the Affordable Care Act (ACA).
    • The USPSTF has historically consisted of 16 clinical experts who evaluate evidence and issue recommendations on screenings, medications, and other preventive care.
  • The USPSTF typically meets three times per year, though the committee has not met since March 2025, as HHS has postponed its last three planned meetings, which have not been rescheduled.
  • Kennedy’s statements raise questions about how the panel could be restructured and how future recommendations may be developed. Any changes to the panel could have direct implications for insurance coverage of preventive services required under federal law.

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