We all want to make it to 39 or 40 weeks, but sometimes life has different plans. Maybe your water breaks, or your cervix starts dilating, or maybe your blood pressure is high. If you find yourself delivering before 37 weeks, first, congratulations on your preemie! Second, you’re not alone. Every year, around 10% of births are delivered prematurely, prior to 37 weeks gestation.

These tiny fighters are stronger than we realize, but preterm infants are not tiny adults. Despite being smaller, weighing less, and being less developed than a full-term infant, the CDC recommends that premature infants be vaccinated on the same vaccine schedule as full-term infants.

If you are wondering whether this medical practice is wise for our littlest members of society, you have come to the right place! I’m not paid by pharma to tell you what they want you to know. I’m a mom telling you what I would want to know. This is not medical advice. This is grab some coffee or tea, and let’s talk mother to mother.

Autism and prematurity

A 2021 study performed in Sweden found that children born before 37 weeks are 40% more likely to be diagnosed with autism than a full term infant. Extremely preterm infants (22–27 wks) are about 4 times more likely to be diagnosed with autism in both boys and girls.

Could this higher prevalence of autism in preemies be an effect of the many factors that relate to being born early, ie. cesarean delivery, antibiotic use, fortifiers, steroids, lack of breastfeeding, timely vaccination? Given that a premature infant is at a higher risk of brain injury, a semi-permeable blood-brain barrier, and have altered colonization of the gut microbiome–could the onslaught of medical interventions for a ‘vulnerable infant’ pose unexpected health risks?

In 2017, researchers examined the relationship between prematurity, vaccination and risk for neurodevelopmental disorders (NDD) and found in their small sampling that none of the unvaccinated premature infants (n=12) had a NDD, whereas 32% of the vaccinated premature infants (12/37) had a NDD. While the overall numbers are small, the study found that vaccination was associated with a 4.3-fold increase in risk for neurodevelopmental disorders.

Baby Brooks Weighed Only 8 Pounds and Died 4 Days after Vaccines

SIDS and prematurity

Research into Sudden Infant Death Syndrome (SIDS) began in the 1960s, after several well-to-do families suffered the loss of their apparently healthy infants during a sleep period and wouldn’t accept pneumonia as the cause of death. In each case, when the baby was put down, they did not have pneumonia or signs of sickness. In one of the cases, 6 month old Mark Addison Roe had just been seen by his doctor 2 weeks before his death and received a routine triple injection (DPT vaccine) and a polio vaccine. His doctor remarked how healthy he was at the visit. While Mark doesn’t fit the age distribution of SIDS (2 to 4 months) nor the socioeconomic characteristics (his family was well to do), nor the ethnic demographics (he was white), nor was he a premature baby (15%-20% of SIDS are premature), his death is what began the research into SIDS.

Premature infants are more vulnerable in general to toxic insults, and have less developed immune systems. Many conditions can make a blood-brain barrier more permeable, including fever, infection, stress, apnea, gut inflammation–most of which occur as a result of vaccinations (and seen in higher rates in premature infants after vaccination). That SIDS is more common in premature infants, may suggest that the immaturity or vulnerability is being exploited to a higher degree by some exogenous stressor.

Vaccine recommendations for premature infants

The standard of care dictates that a premature infant is vaccinated based on their chronological age, rather than their adjusted age–the latter which takes into account that they were born early and “adjusts” for that.

According to the CDC:

In the majority of cases, preterm infants (infants born before 37 weeks’ gestation), regardless of birth weight, should be vaccinated at the same chronological age and according to the same schedule and using the same precautions as for full-term infants and children. 

Interestingly, adjusted age is used to track an infant’s developmental milestones.

“For a preterm baby, it is important to use the baby’s adjusted age when tracking development until 2 years of age so that his growth and progress take into account that he was born early.”

Isn’t it curious that premature infants are allowed to go by “adjusted age” for developmental milestones, but are expected to be developmentally mature when it comes to vaccines?

Exceptions to the ‘vaccinate on schedule’ rule

Hepatitis B vaccine:

For hepatitis B negative mothers, the CDC advises to delay the birth dose of the Hepatitis B vaccine in preterm infants weighing less than 2,000 grams until the infant reaches 1 month or administered at hospital discharge.

The reason cited is because the immune system has not matured enough. Research has shown that premature infants don’t make protective antibodies to many vaccines given too early.

For example, this 1999 study recruited 118 infants born before 37 weeks gestation, and administered the hepatitis B vaccine in the first week of life, at 1 to 2 months of age, and at 6 to 7 months.

“The seroprotection rate (attaining >/=10 mIU/mL HBS antibody) after two doses was low (25%) regardless of birth weight; infants weighing <1000 g at birth had the poorest response (11%).”

Despite the recommendation to delay the birth dose of HepB, many premature infants still receive the vaccine at birth.

For example, in this paper 29% of infants born between 27 and 31 weeks gestation received the HepB vaccine within 3 days of birth, compared 75% of infants born between 37 and 43 weeks gestation. This early vaccination of preterm infants makes absolutely zero sense.

Rotavirus:

For infants who reach two months of age in the NICU, the rotavirus vaccine is advised to be administered just before hospital discharge due to rotavirus vaccine having the ability to transmit to others, ie. vulnerable babies, and cause an outbreak. The vaccine contains live rotavirus which may transmit to others via the fecal-oral route.

“If a child aged at least 6 weeks has been in the hospital since birth, deferral of rotavirus vaccine is recommended until the time of discharge. If an infant were to be vaccinated with rotavirus vaccine while still needing care in the NICU or nursery, at least a theoretic risk exists for vaccine virus being transmitted to infants in the same unit who are acutely ill and to preterm infants who are not age-eligible for vaccine.”

This may be one reason why daycare centers often have “rotavirus outbreaks.”

Other injections

RSV Immunoglobulins

There are two immunoglobulin products that may be administered to preterm infants: Synagis and Beyfortus. Neither are actually immunizations, therefore these products are outside the scope of this article. However, please read through their product inserts.

• Beyfortus Ingredients: Each 0.5 mL contains 50 mg nirsevimab-alip, arginine hydrochloride (8 mg), histidine (1.1 mg), L-histidine hydrochloride monohydrate (1.6 mg), polysorbate 80 (0.1 mg), sucrose (21 mg), and water for injection (USP). The pH is 6.0. Beyfortus Product Insert
• Synagis Ingredients: Each 100 mg single-dose vial of Synagis liquid solution contains 100 mg of palivizumab and also contains chloride (0.5 mg), glycine (0.1 mg), and histidine (3.9 mg), in a volume of 1 mL. Synagis Product Insert

How are premature infants different than full-term infants?

Before digging into what vaccines are given, and their potential adverse effects, let’s understand how premature infants are different than full-term infants with regard to vaccinations. 

2 months

There are 6 vaccines given at the 2 month well baby visit against 8 different diseases. This includes 5 separate injections (which sometimes can be combined in combination vaccines) and 1 oral vaccine:

• Hepatitis B vaccine (Hep B)
• Rotavirus Vaccine (RV) (oral)
• Pneumococcal Conjugate vaccine (PCV)
• Diphtheria-Tetanus-acellular Pertussis vaccine (DTaP)
• Haemophilus Influenzae vaccine (Hib)
• Inactivated Polio vaccine (IPV)

4 months

• Hepatitis B vaccine (Hep B)
• Rotavirus Vaccine (RV) (oral)
• Pneumococcal Conjugate vaccine (PCV)
• Diphtheria-Tetanus-acellular Pertussis vaccine (DTaP)
• Haemophilus Influenzae vaccine (Hib)
• Inactivated Polio vaccine (IPV)

6 months

• Hepatitis B vaccine (Hep B)
• Rotavirus Vaccine (RV) (oral)
• Pneumococcal Conjugate vaccine (PCV)
• Diphtheria-Tetanus-acellular Pertussis vaccine (DTaP)
• Haemophilus Influenzae vaccine (Hib)
• Inactivated Polio vaccine (IPV)
• COVID-19
• Influenza

 

Read more about these vaccines by checking out the vaccine inserts page.

What happens to baby after vaccination?

In 2013, Tammy Movsas conducted a study on 15 preterm infants who were still in the NICU and due for their 2 month vaccines.

The author writes:

Parenteral feedings containing more than 4 to 5 µg/kg/d of aluminum have been shown to result in neurodevelopmental delay in preterm infants. However, an infant at the 2-month checkup receives multiple aluminum-containing vaccines that in combination may have as high as 1225 µg of intramuscular aluminum; this is a much higher intramuscular aluminum dose than the safely recommended intravenous aluminum dose.

The objective of the study was to measure prevaccine and postvaccine levels of aluminum in the serum and urine of preterm infants, a population a higher risk of aluminum neurotoxic effects. The paper also explored prevaccine and postvaccine levels of essential elements, and markers of inflammation.

Curiously, the paper does not share the postvaccine levels of aluminum–atypical for such a paper whose main objective was to measure prevaccine and postvaccine levels.

The author writes:

No significant change in levels of urinary or serum aluminum were seen after vaccination (Table). Significant declines were noted postvaccination in serum iron (58.1%), manganese (25.9%), selenium (9.5%), and zinc (36.4%) levels, as was a significant increase in serum copper level (8.0%). A rise in selenium level was the only significant urine change.

As you can see in the table below, there is no postvaccine level of aluminum reported.

The author writes in her discussion:

We were reassured to find no significant postvaccine rise in serum aluminum level after vaccination of preterm infants with vaccines containing a total of 1200 µg of aluminum. The average study infant weighed 2200 g at vaccination and thus received about 545 µg/kg of intramuscular aluminum.

Again, we have to take her word for it because for some unknown reason she didn’t share the actual results. We know that each person is different, so was there variability between the 15 infants in postvaccine serum or urine aluminum? If numbers were not significantly high, why not share? If the aluminum was neither in the urine nor the blood, where was it? When will the aluminum be processed and move through the body? When will it enter the blood stream, and what toxicity will it have? Will it look different for different infants, depending on their unique set of host factors?

Remy’s Story: Sudden Death the Same Night of his 2-Month Shots

Vaccine reactions in the premature infant

Apnea / Cardiorespiratory Events

A 1997 study sought to determine the frequency of apnea episodes in premature infants after vaccination. Apnea is a temporary cessation of breathing, especially during sleep.

“…12 (12%) infants experienced a recurrence of apnea, and 11 (11%) had at least a 50% increase in the number of apneic and bradycardic episodes in the 72 hours after immunization. 

A 2004 observational study evaluated the safety of hexavalent vaccines (DTaP-IPV-Hib) in 78 preterm infants, and found that immunization triggered transient cardiorespiratory events (apnea, bradycardia, desaturations) in 47% of infants. Infants with pre-existing cardiorespiratory symptoms appeared to have a 5-fold to 8-fold increase in risk of cardiorespiratory events post immunization.

A 2023 Indian paper documented the adverse cardiorespiratory events following first routine immunization in preterm infants with gestational age less than 30 weeks. Of 161 neonates ≤30 weeks, 21 (13.7%) experienced cardio-respiratory adverse events. Lower gestational age, bronchopulmonary dysplasia and sepsis were significant risk factors on univariate analysis. 

A 2023 systematic review of the safety of pentavalent and hexavalent vaccination of extremely and very-to-moderate preterm infants born at less than 34 weeks and/or under 15oo grams found:

“The results of these studies suggest … side effects of penta- and hexavalent vaccines are also mostly similar to those seen in full-term babies. However, side effects like pauses in breathing, slow heart rate or low blood oxygen levels seem to be more common in preterm babies; for safety, these babies should be monitored closely after vaccination.”

A 2006 study found nearly half of the preterm infants born < 32 weeks experienced increased episodes of apnea, bradycardia, and/or desaturations (ABD) after vaccination:

Fifty-six immunized infants (45.1%) and 36 control infants (29.0%) had a resurgence of or increased ABD in the 72 hours post-immunization in the immunized infants and at the same post-natal age in the controls with an adjusted odds ratio for immunized infants of 2.41 (95% CI 1.29,4.51) as compared to control infants.

Fever

A 2005 paper studied some of the adverse effects of newer vaccines at that time in preterm infants. A total of 48 very preterm infants were immunized during the period. Low-grade fever (>37.5 degrees C per axilla) occurred in 16 (33%) infants after immunization, but none before immunization (P < 0.001). Four (8%) infants underwent a septic work up post-immunization. The C-reactive protein was increased in all four infants, but other tests for sepsis were negative.

Crying, Vomiting, Irritability

Vaccine trials contain some data on these more common short-term vaccine adverse reactions. Vaccine clinical trials typically compare one vaccine to another vaccine, so both case and control would be given a vaccine, thus rates of adverse reactions are typically similar between both groups. We wouldn’t be able to compare rates to unvaccinated in this case. This clinical trial of the hexavalent vaccine DTaP-IPV-Hib-HepB in a hexavalent vaccine studied in >6,800 children (160 premature) reported that nearly 80% of infants experienced increases in crying, 85% irritability, 30% vomiting, 75% somnolence.

Between 2% and 4% of infants experienced a Serious Adverse Event (SAE), which is usually defined as hospitalization.

Death

In the hexavalent clinical trial mentioned above, there was one “unrelated” death in the premature cohort (160 infants) in an infant who developed pneumonia >3 weeks after receiving the control and concomitant vaccines. No further information is available on the death. But pneumonia is a common vaccine side effect. See below.

Gastrointestinal Disorders

A study examining the immune responses and safety profile of 13-valent pneumococcal conjugate vaccine (PCV13) in preterm infants compared with term infants found that 13% of preterm infants developed a gastrointestinal disorder, compared to 4% of term infants.

Serious Adverse Events

A Serious Adverse Event is an event that requires hospitalization, results in disability or permanent damage, or ends in death.

In the study on PCV13, 14% of preterm infants had a serious adverse event (SAE), compared to 5% of term infants.

“One term subject and 1 preterm subject experienced febrile convulsions (139 days after dose 3 and 17 days after dose 4, respectively); neither event was considered vaccine related due to the presence of a simultaneous acute febrile illness (bronchopneumonia and respiratory tract infection, respectively).”

The preterm infant experienced febrile convulsion 17 days after vaccination and is said to have had a respiratory tract infection post vaccination. Respiratory illness and seizure are common post vaccination side effects (especially considering that dose 4 would probably have lined up with MMR vaccination) so it is unknown how the trial author was able to determine no relationship.

The report continues:

Infections were the most common SAEs at all doses, with lower respiratory tract infections predominating. During and after the infant series, SAEs of bronchiolitis, pneumonia, and upper respiratory tract infections were reported in 6, 5, and 2 preterm infants, respectively, and by 2, 1, and 0 term infants.

A 2015 paper examined the rate of serious adverse events in a 3 day window of extremely low birthweight infants (n=13,926 infants) in the NICU and assessed:

To compare the incidence of sepsis evaluations, need for increased respiratory support, intubation, seizures, and death among immunized ELBW infants in the 3 days pre- and post-immunization.

The study found:

The incidence of sepsis evaluations increased from 5.4/1000 patient days in the pre-immunization period to 19.3/1000 patient days post-immunization (adjusted rate ratio [ARR], 3.7; 95% CI, 3.2–4.4). The need for increased respiratory support increased from 6.6/1000 patient days in the pre-immunization period to 14.0/1000 patient days post-immunization (ARR, 2.1; 95% CI, 1.9–2.5), and intubation increased from 2.0/1000 patient days to 3.6/1000 patient days (ARR, 1.7; 95% CI, 1.3–2.2). The post-immunization incidence of adverse events was similar across immunization types, including combination vaccines when compared to single-dose vaccines. Infants who were 23–24 weeks gestation had a higher risk of sepsis evaluation and intubation post-immunization. A prior history of sepsis was associated with higher risk of sepsis evaluation post-immunization.

The paper reported 5 deaths in the 3 day post-immunization period:

Three of the 5 infants who died in the 3 days post-immunization had a diagnosis associated with death available in the dataset; one infant had a bowel perforation, one infant had necrotizing enterocolitis and presumed sepsis, and one infant had pneumonia and respiratory failure. 

I wish we were given information on how many deaths occurred outside the 3 day post vaccine window.

In Conclusion

Research into the actual risks of vaccinating premature infants is limited. It’s limited by one vaccine at a time. It’s limited by short post vaccination windows. It’s limited because like most vaccinated vs unvaccinated studies, there is no funding for a study that would inadvertently prove that vaccines pose harm, even for select groups. We aren’t tracking how premature infants are doing once they grow up, after receiving all the recommended vaccines, and comparing them against a control group of unvaccinated children. As parents we want the whole picture before choosing medical treatments. I wish I knew the answer.

Maybe they would say that avoiding the various infectious diseases that vaccines target is worth the risk? Even though vaccine failure, vaccine waning, and vaccine risks aren’t properly studied or quantified–makes it really hard to tell what the trade-off here is.

I hear vaccine supporters say that vaccination is a social contract. That it’s something we should do as a society to make sure infectious diseases of eras past stay at bay. That we should do it to protect others. While I think that’s a very noble idea, where’s the part of the contract that says if someone has an injury, they will be helped out? That if our child develops a new chronic health condition, or tragically dies after a vaccine, that we will be supported, honored, respected, compensated and taken care of? Because social contracts go both ways.

While the National Vaccine Injury Compensation Program has paid out over $5 billion since 1988, most vaccine injuries and reactions don’t qualify by the narrow “table injuries.” This extreme denial of, and lack of concern for the vaccine injured is the reason people like me exist in this space.

Micro Preemie Defies Odds and Thrives Without Formula or Vaccines

Further Research:

Impact of Breastfeeding on the Incidence and Severity of RSV Bronchiolitis in Infants: Systematic Review

The Impact of Human Milk on Necrotizing Enterocolitis: A Systematic Review and Meta-Analysis

Breastfeeding for reducing the risk of pneumonia morbidity and mortality in children under two: a systematic literature review and meta-analysis

Breastfeeding and the risk for diarrhea morbidity and mortality

Association of Breastfeeding for the First Six Months of Life and Autism Spectrum Disorders: A National Multi-Center Study in China

Association of breastfeeding status with risk of autism spectrum disorder: A systematic review, dose-response analysis and meta-analysis

Duration of Breastfeeding and Risk of SIDS: An Individual Participant Data Meta-analysis

Maternal milk feedings reduce sepsis, necrotizing enterocolitis and improve outcomes of premature infants