Vaccine
Talk

Immunize.org and the Autism Science Foundation updated their Evidence Shows Vaccines Unrelated to Autism resource.

Extensive scientific research and reviews by global medical authorities confirm that vaccines are unrelated to the development of autism. Multiple large-scale studies have refuted links between autism and the MMR vaccine, thimerosal-containing vaccines, or the total number of vaccines administered to children.

Scientific Consensus on MMR and Autism

Independent groups of experts, including the National Academy of Medicine, have reviewed the evidence and concluded that the MMR vaccine does not cause autism.

• Study Scale: Research includes massive population studies, such as a Danish cohort of over 650,000 children, which found no increased risk for autism following vaccination.
• High-Risk Groups: Studies specifically looking at children with older siblings who have autism (a higher-risk group) found no association between the MMR vaccine and the development of ASD.
• Retracted Research: The original 1998 claim of a link between MMR and autism was found to be based on falsified data and "dishonest and irresponsible research". The study was fully retracted, and the doctor's medical license was revoked.

Thimerosal and Immune System Capacity

Concerns regarding vaccine ingredients or "overwhelming" a baby's immune system are not supported by clinical evidence.

• Thimerosal: This mercury-based preservative (ethylmercury) is cleared from the body quickly and is not linked to autism. Even after its removal from most childhood vaccines in 2001, autism rates continued to rise, further proving no correlation.
• Antigens: A baby's immune system encounters significantly more antigens daily from common bacteria and viruses than those found in the entire childhood vaccination schedule.

Known Risk Factors for Autism

While the exact causes of autism are still being studied, current research emphasizes genetic and environmental factors rather than vaccines.

• Genetics: Over 100 genes associated with brain development have been identified as risk factors. Brain differences in children with ASD can be detected as early as six months of age, often before vaccines are administered.
• Environmental Factors: Factors linked to increased ASD risk include maternal infections with fever during pregnancy, high levels of air pollution, and certain medications like valproic acid.
• Prevalence: The rising number of autism diagnoses is largely attributed to increased awareness, better diagnostic practices, and expanded access to services.

“The Impact of a Pneumococcal Vaccination on Disease Activity in Children and Adolescents with Inflammatory Bowel Disease: A 2-Year Prospective Study” published in Expert Review of Vaccines

In its March 30 issue, Expert Review of Vaccines published The Impact of a Pneumococcal Vaccination on Disease Activity in Children and Adolescents with Inflammatory Bowel Disease: A 2-Year Prospective Study. The study was designed to evaluate whether PCV13 administration was associated with flare ups in pediatric inflammatory bowel disease (IBD) patients. The study concluded that a single dose of PCV13 does not increase inflammatory bowel disease activity in pediatric IBD patients during the 24 months following vaccination. A portion of the abstract appears below.

Infectious diseases are known triggers for inflammatory bowel disease (IBD) exacerbations. Although vaccines can prevent many such infections, hesitancy persists among pediatric IBD patients and their caregivers due to concerns about vaccine-induced disease flare-ups. The aim of the study was to evaluate the impact of the 13-valent pneumococcal conjugate vaccine (PCV13) on disease activity in children and adolescents with IBD over a 24-month period post-vaccination. . . .

This prospective, multicenter cohort study included IBD patients aged 4-18 years. Participants were assigned to a vaccinated group (single PCV13 dose) or an unvaccinated control group. Disease activity was monitored using PUCAI/PCDAI [Pediatric Ulcerative Colitis Activity Index/ Pediatric Crohn's Disease Activity Index] scores, and exacerbation rates were recorded at 6, 12, 18, and 24 months. . . .

A total of 279 patients (52.3% male; median age, 167 months) were enrolled, of whom 93 (33.3%) received PCV13. The control group showed higher, but not statistically significant, disease activity at any time point (p = 0.06 . . .) and exacerbation rates (p = 0.47 . . .). . . .

A single dose of PCV13 does not increase disease activity in pediatric IBD patients during the 24 months following vaccination.

FDA expands license for GSK's RSV vaccine (Arexvy) to include high-risk adults age 18 to 49 years

On March 13, FDA expanded the indicated age range for Arexvy (RSV vaccine, GSK). This approval expands the indication to include adults age 18 through 49 years who are at increased risk for lower respiratory tract disease (LRTD) due to RSV. Arexvy should not be used during pregnancy. Arexvy's license continues to include adults age 60 years or older and adults age 50 through 59 years with high-risk conditions for severe RSV disease.

Due to the stay of ACIP activities, it is not known when CDC recommendations for use of this product will be considered.

Three RSV vaccines are now licensed for all adults age 60 years or older AND adults age 18 through 59 years with high-risk conditions for severe RSV disease:

• Arexvy (RSVpreF3, GSK)
• Abrysvo (RSVpreF, Pfizer)
• mResvia (mRNA RSV, Moderna)

American Academy of Family Physicians releases its 2026 recommended schedules for children and adolescents and for adults

On March 1, American Academy of Family Physicians (AAFP) released its 2026 immunization schedules. The AAFP's guidance aligns with the AAP's 2026 childhood schedule and carries forward the 2025 adult schedule with targeted updates. Both schedules provide clear, practical, evidence-based recommendations.

GSK Pentavalent Meningococcal Vaccine Endorsed by ACIP

CDC's Advisory Committee on Immunization Practices (ACIP) endorsed a new GSK pentavalent meningococcal vaccine (MenACWY-CRM/MenB-4C, Penmenvy) for use in people aged ≥10 years when both MenACWY and MenB are indicated.

Safety Profile: The paper is refreshingly transparent about the science, noting: "Serious adverse events possibly related to vaccination were rare and occurred at similar frequencies in pentavalent and control groups."

Health System Impact: On health system impact: "Using pentavalent vaccine as an alternative to concomitant administration of MenACWY and MenB was the most cost-saving of the policy questions considered."

Clinical Significance: For clinicians, researchers, and immunization program managers, this recommendation is less about novelty — and more about implementation efficiency, equity, and real-world feasibility.