JONATHAN M. METSCH, Dr.P.H. – Tracking Emerging Public Health Challenges – April 4,9 2026 – COVID
The stalled publication has sparked concerns that information conflicting with the views of Health and Human Services Secretary Robert F. Kennedy Jr. — a longtime vaccine skeptic — may be sidelined. The CDC, however, insists the move followed standard procedure.
The new report found that healthy adults who received the Covid vaccine cut their risk of urgent care and emergency visits by 50 percent, and Covid-related hospitalizations by 55 percent, compared to adults who did not receive a dose in 2025 or 2026, according to The Washington Post.
The research was due to be published March 19 in the Morbidity and Mortality Weekly Report, the CDC’s premier scientific journal.
The study had been green-lit by the CDC’s scientific review process but acting CDC Director Jay Bhattacharya delayed the report over methodological concerns, two unnamed scientists familiar with the matter told the outlet.”
“The postponement occurred despite the CDC’s long history of using the same methodology to assess respiratory virus vaccines, including flu shots. Those methods also underpinned a 2021 New England Journal of Medicine study on Covid vaccine effectiveness.” (1)
“Dr. Debra Houry, who served as the C.D.C.’s chief medical officer before she resigned in August, said, “A political appointee at C.D.C. would be very rarely involved in a review or decision regarding M.M.W.R.,” referring to the journal.
“Previously this would have been reviewed by a career scientist who worked across administrations,” like the chief medical officer, Dr. Houry said. Given staffing shortages at the agency, continuing health threats like measles and Dr. Bhattacharya’s duties as director of another agency, “this would be even more unusual to do,” she added.
But Andrew Nixon, a spokesman for the Department of Health and Human Services, said in an emailed statement, “It’s routine for C.D.C. leadership to review and flag concerns about M.M.W.R. papers, especially relating to their methodology, leading up to planned publication.”
“Dr. Bhattacharya expressed concerns about the observational method used in this study to calculate vaccine effectiveness, and the scientific team is working to address these concerns,” Mr. Nixon added. “Dr. Bhattacharya wants to make sure that the paper uses the most appropriate methodology for such a study.”” (2)
“The diagnosis is simple: “Our health-care system broke in 2020,” says Dr Tom Dolphin, an anaesthetist in London and boss of the British Medical Association. “We like to pretend it didn’t, but it really did.” In the early months of 2020, hospitals paused normal activity to free up beds as they braced for a wave of covid-19 patients. The strategy helped in a moment of crisis. But, several years on, it is becoming clear that those measures did lasting damage to health-care systems. Understanding why is less straightforward.” (3)
“A new, “highly mutated” COVID strain is quickly gaining ground in the United States, according to new data.
Variant BA.3.2, nicknamed “Cicada,” first drew the attention of health officials earlier this year when the Centers for Disease Control and Prevention and the World Health Organization noted it had appeared in at least 23 countries and accounted for up to 30% of cases in some Eastern European locales.
The United States may be following suit, according to new wastewater data. While Cicada accounted for a very small number of U.S. cases (less than 4%) when the CDC first released a report in mid-March, information gathered by WasteWaterSCAN, a Stanford University-led tool for tracking the spread of disease, found that it now accounts for more than 20% of tested COVID infections as of early April.
While COVID activity is down significantly since the winter, BA.3.2 is appearing more often. Here’s what to know about the variant picking up speed in the United States.” (4)
“Vaccine makers Pfizer (PFE.N) and BioNTech (22UAy.DE), halted a large U.S. trial of their updated COVID-19 vaccine in healthy adults aged 50 to 64, saying enrollment in the trials had been too low to generate the needed data.
In a letter to trial investigators dated March 30, seen by Reuters and previously unreported, Pfizer said it would stop surveillance for signs of COVID illness for all participants in the study after April 3.
Enrollment was closed on March 6, following a review of current epidemiological trends, it said.
The move comes as COVID vaccine makers grapple with pushback from the U.S. administration and weak U.S. demand for the shots.
The U.S. Food and Drug Administration toughened requirements for COVID vaccine use last year, including asking for large, placebo-controlled trials in the 50-64 age group for it to be included in recommendations.
Pfizer and BioNTech told Reuters they had informed the FDA about their intent to halt the COVID-19 vaccine study, citing challenges getting enough participants. The target enrollment was roughly 25,000 to 30,000 participants.” (5)
Multipurpose anti-viral pill may treat colds, norovirus, flu and covid, https://www.newscientist.com/article/2521670-multipurpose-anti-viral-pill-may-treat-colds-norovirus-flu-and-covid/
1.RFK Jr’s CDC delays report showing benefits from Covid vaccine, insiders say, by Brendan Rascius, https://www.independent.co.uk/news/world/americas/us-politics/covid-vaccine-report-delay-rfk-cdc-b2954482.html
2.Top C.D.C. Official Delays Report on Covid Shot’s Effectiveness, By Apoorva Mandavilli, https://www.nytimes.com/2026/04/09/health/cdc-bhattacharya-covid-shot-report-delay.html?smid=nytcore-ios-share
3.Hospitals never recovered from covid-19, https://www.economist.com/international/2026/04/09/hospitals-never-recovered-from-covid-19
4.US cases of COVID variant ‘Cicada’ up more than 15% and rising, by Mary Walrath-Holdridge, https://www.cnn.com/2026/04/02/health/new-covid-variant-cicada
5.Exclusive: Pfizer, BioNTech halt US COVID vaccine study after recruitment struggles, By Bhanvi Satija, https://www.reuters.com/business/healthcare-pharmaceuticals/pfizer-biontech-halt-us-covid-vaccine-study-after-recruitment-struggles-2026-04-01/
curated by Jonathan M. Metsch, Dr.P.H.
Clinical Professor of Environmental Medicine, Icahn School of Medicine at Mount Sinai