🚨 More statistics and points to common immuzation questions:Â
1. Do vaccines still contain mercury and aluminum?
Mercury (Thimerosal): Removed from childhood vaccines in 2001, except some multi-dose flu vaccines. The type used (ethylmercury) is processed much faster than the mercury in fish and hasn’t been shown to cause harm.
Pichichero et al., Lancet (2002) measured infant blood-mercury levels post-vaccination and found they remained well below the EPA safety limit (typically 1–2 ng/mL, max ~4 ng/mL vs. EPA limit of 5.8 ng/mL).
Madsen et al., Pediatrics (2003) studied autism rates in Denmark before and after thimerosal’s removal and found no decrease in autism rates after it was eliminated, countering the idea that it was a causal factor.
 Aluminum: Some vaccines contain tiny amounts to help the immune response. However, babies get far more aluminum from breast milk or formula than from vaccines.
Breast milk: ~7 mg
Formula: ~38 mg
Vaccines (first 6 months): ~4.4 mg (Source: Mitkus et al., Vaccine, 2011)
The FDA and WHO have extensively reviewed the safety of aluminum adjuvants and found no credible evidence of harm at these levels. (Keith et al., Risk Analysis, 2002)
 ✅ Bottom line: Thimerosal is no longer in routine childhood vaccines, and aluminum exposure is minimal compared to daily intake from food.
2. Are vaccines tested in double-blind, placebo-controlled trials?
âś… Yes! Just like other medications, vaccines go through rigorous trials.
Examples:
The polio vaccine trial (1954) was one of the largest randomized, placebo-controlled studies in history, with 1.8 million children (Francis et al., JAMA, 1955)
The rotavirus vaccine (RotaTeq, 2006) was tested in a placebo-controlled trial of ~70,000 infants across 11 countries (Vesikari et al., NEJM, 2006).
Modern vaccines like HPV and COVID-19 vaccines have also been tested in large double-blind trials, with the Pfizer and Moderna COVID-19 vaccines each enrolling 30,000–40,000 participants (Polack et al., NEJM, 2020).
📌 In cases where a new vaccine is replacing an older one, it's often tested against the existing vaccine (not saline) for ethical reasons
 ✅ Bottom line: Vaccines are tested with the same (or stricter) scientific methods as other drugs
3. Who funds vaccine research?
A mix of government agencies (NIH, CDC), independent institutions, and pharma companies, but regulatory agencies like the FDA and WHO require full transparency.
A 2019 study on MMR vaccines and autism was funded by the Danish Ministry of Health and the Novo Nordisk Foundation, showing independent research validates vaccine safety (Hviid et al., Annals of Internal Medicine, 2019)
The Oxford-AstraZeneca COVID-19 vaccine was developed with 97–99% public and charitable funding (BMJ Global Health, 2021)
Clinical trials have Institutional Review Boards (IRBs) that monitor data for safety/fairness. Regulatory agencies (FDA, EMA) do not rely solely on company data – they review raw data and often require confirmatory or independent analyses
📌 Oversight matters:
FDA/CDC do not rely solely on company data- they review raw trial data and require independent confirmation
Post-approval, vaccine safety is tracked independently through VAERS and the Vaccine Safety Datalink to track any concerns (Shimabukuro et al., Vaccine, 2015).
 ✅ Bottom line: Research is funded by both public and private sources, but strict oversight exists no matter the funding.
4. Do doctors profit from vaccines?
❌ No, doctors don’t make money pushing vaccines. In fact, many lose money due to storage costs, insurance issues, and under-reimbursement.
A common myth is that doctors push vaccines for financial gain. This one, I promise you, isn’t true. I’ll be honest, doctors sometimes do practice differently to try to make more money. This may include being very specific in documentation so that they can bill insurances for more. But I promise you, there is no money to be made by recommending vaccines.
Typical reimbursement: $10-$25 per vaccine administration
Vaccine storage, spoilage, and staff costs often outweigh these payments
A CDC survey found over half of private practices either broke even or lost money on vaccines (Freed et al., Pediatrics, 2009)
Some state Medicaid programs reimburse as little as $2–$3 per shot, which is far below the cost of storage, administration, and counseling (Coleman et al., Pediatrics, 2009)
 ✅ Bottom line: Vaccines are not a financial incentive for doctors. Many give them at cost or lose money.
5. Why do newborns get the Hepatitis B vaccine? Are they even at risk for the disease?
Hepatitis B can be spread through blood or bodily fluids, and infants infected at birth have a 90% chance of chronic infection leading to liver failure or cancer later in life (Chang et al., NEJM, 1997).
The birth dose is crucial because some mothers may have undiagnosed infections, and newborns are particularly vulnerable
Universal newborn vaccination virtually eliminated hepatitis B in U.S. children and is a global strategy recommended by the WHO (Schillie et al., MMWR, 2018)
Just based on this data alone, I think the benefits of vaccination significantly outweigh the benefits.
 ✅ Bottom line: The risk of Hep B is much higher than the risk of the vaccine.
6. Do vaccines cause autism?
❌ No. And this one has been thoroughly studied!
A large body of rigorous research shows no link between vaccines and autism. Over the past two decades, dozens of epidemiological studies – in multiple countries and millions of children – have compared vaccinated vs. unvaccinated populations and found no difference in autism rates.
A 2014 meta-analysis of 1.2 million children found no link between vaccines and autism (Taylor et al., Vaccine, 2014)
A Danish cohort study (2019) of 657,000 children found no increased risk of autism with MMR vaccination, even in high-risk groups (Hviid et al., Annals of Internal Medicine, 2019)
Autism rates continued rising even after thimerosal was removed from vaccines, disproving any link (Madsen et al., Pediatrics, 2003)
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??? So, why are rates of autism going up ???
The increase in autism diagnoses is largely due to broader diagnostic criteria, increased awareness, and better screening, not vaccines (King et al., JAMA Pediatrics, 2019).
Factors behind the rise in autism diagnoses:
The prevalence of autism spectrum disorder (ASD) has increased in recent decades, but experts attribute this primarily to changes in diagnostic criteria, improved awareness, and better identification, rather than a true spike in new cases caused by an environmental toxin.
Diagnostic criteria for autism broadened substantially with the introduction of the DSM-IV and now DSM-5, which means many children who would not have been labeled autistic in the past are now diagnosed on the spectrum (including those with milder symptoms).
There are also systematic screening programs – pediatricians now screen toddlers for autism at 18 and 24 months, catching cases that previously might have been missed
Greater awareness by both parents and doctors has led to more evaluations and thus more identified cases, even at older ages (e.g., teens and adults being diagnosed now who grew up when criteria were narrower)
Studies have shown that this “diagnostic substitution” and expansion can explain a large portion of the increase.
-  An analysis in California found about 25% of the increase from 1992–2005 could be explained by children who would previously have been diagnosed with intellectual disability now being diagnosed with autism under updated criteria
- Â Other research suggests that when you account for factors like older parental age and having kids in smaller age gaps (which slightly raise autism risk), plus the diagnostic changes, the majority of the rise is accounted forÂ
-  Autism Speaks summarizes that improved detection and broader definitions are the driving forces behind higher reported prevalence, with other factors (genetic changes, unknown environmental factors) “likely a small part of the increase”
 ✅ Bottom line: Today, major health organizations and independent autism researchers agree that vaccines do not cause autism.
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More on autism because I think it’s important to talk about where the fear around vaccines started:
The original 1998 study that raised this question (by Andrew Wakefield) was found to be fraudulent and was retracted. But a lot of damage was done to cause fear around vaccines.
In contrast, dozens of high-quality studies have consistently found no link. These studies have been conducted by independent researchers, often funded by government or non-profit institutions to eliminate industry bias.
Reviews by the Institute of Medicine (2004) and the Autism Science Foundation have concluded that the evidence overwhelmingly refutes any association between vaccines and autism.
Instead, autism is now understood to have strong genetic underpinnings – studies of twins show ASD is highly heritable – with multiple genes and some prenatal environmental factors (such as extreme prematurity, or certain prenatal exposures) contributing to risk. The “rise” in autism largely reflects that we are identifying autism more often, not that something new (like vaccines) suddenly started causing itÂ
âś…Final Thoughts
I totally understand why these questions come up—it’s good to be cautious about what goes into our bodies! The reason the vaccine schedule has expanded is because we can now prevent more serious diseases than ever before. I really appreciate the science and advancements we’ve made. People are healthier and live longer than ever before!
📌 Vaccines are extensively tested, continuously monitored, and are among the safest and most effective public health measures.