Vaccines, Doses & Shots. Confused?

In a phone conversation with Robert F. Kennedy, Jr. regarding childhood vaccinations last month, Donald Trump said:

When you feed a baby, Bobby, a vaccination that is, like, 38 different vaccines and it looks like it’s been for a horse. Not a, you know, 10-pound or 20-pound baby. And then you see the baby all of a sudden starting to change radically. I’ve seen it too many times. And then you hear it doesn’t have an impact, right?¹

Within two days of this conversation, FactCheck.org published an article titled “Trump Repeats Falsehoods About Childhood Vaccines in Leaked Phone Call With RFK Jr.” The piece by Jessica McDonald noted that “no childhood vaccine or combination of vaccines targets 38 diseases at once.” That’s true. However, McDonald conveniently missed the central point Trump was trying to make—that children in the United States get a whole lot of different vaccines for viral and bacterial infections within a very short period of time after they’re born.²

In 1983, the U.S. Centers for Disease Control and Prevention (CDC) recommended that children receive 23 doses of seven vaccines by six years of age. These included vaccines for diptheria, measles, mumps, pertussis (whooping cough), polio, rubella, and tetanus. Two decades ago, CDC officials recommended 38 doses of 12 vaccines by age six. These included vaccines for diptheria, Haemophilus influenzae (Hib), hepatitis A (HepA or HAV), hepatitis B  (HepB or HBV), measles, mumps, pertussis, pneumococcal (PCV), polio, rotavirus, rubella, and varicella (chickenpox).^{3 4 5 6 7}

That is what Trump was referring to, albeit somewhat inarticulately.

Combination Vaccines are Confusing

It is a common and honest mistake to confuse the word vaccines with the word doses and also the words shots or injections. Most people tend to use the words interchangeably, but it doesn’t always work. Here’s why:

Take, for example, the “measles vaccine,” known as MMR, which stands for measles, mumps and rubella vaccines. It is a “combination vaccine,” which means that it combines two or more vaccines together into one shot. The idea is simply to reduce the number of individual shots. The MMR vaccine is often referred to as one vaccine when, in fact, it is three vaccines. It contains one dose of each of the three vaccines.^{8 9}

The CDC recommends two shots of MMR—the first is recommended to be given between 12 and 15 months of age and the second shot between four and six years old. Two shots of MMR equals two doses of measles vaccine, two doses of mumps vaccine and two doses of rubella for a total six doses of three vaccines. But you could also reasonably refer to these as six vaccines (two measles, two mumps and two rubella), and some people might characterize these as simply two vaccines (two MMRs). Lots of room for confusion about what getting two MMR shots really means.

The same logic applies to the combination DTaP vaccine. DTaP vaccine stands for diphtheria, tetanus and acellular pertussis vaccines. The CDC recommends six shots of DTaP—the first at two months, the second at four months, the third at six months, the fourth between 15 and 18 months, the fifth between two and six years, and the sixth (Tdap) between 11 and 12 years old. The six shots of DTaP is the equivalent of 18 doses of three vaccines. Some might refer to these as 18 vaccines (six diphtheria, six tetanus and six acellular pertussis), and some may characterize these simply as six vaccines because they are given in six shots.¹⁰

There are several other combination vaccines that are licensed for use in the United States, including Kinrix, Pediarix, Pentacel, ProQuad, Quadracel, and Vaxelis. Kinrix, which is manufactured and sold by GlaxoSmithKline (GSK), combines the DTaP and IPV (inactivated polio) vaccines—four vaccines into one shot. Quadracel (Sanofi Pasteur) also combines the DTaP and IPV vaccines or four vaccines into one shot. ProQuad (Merck) combines the MMR and varicella vaccine or four vaccines in one shot. Pediarix (GSK) combines DTaP and HepB and IPV or five vaccines in one shot. Pentacel (Sanofi Pasteur) combines DTaP and HepB and IPV or five vaccines in one shot. Vaxelis, produced by Merck and Sanofi Pasteur through a joint partnership, combines DTaP and IPV and Hib and HepB or six vaccines in one shot.⁹

Today, the CDC recommends children receive 53 doses of 16 vaccines between the day of birth and age six. These include RSV, COVID-19, diphtheria, Hib, HepA, HepB, influenza, measles, mumps, pertussis, PCV, polio, rotavirus, rubella, tetanus and chickenpox. Note that the mRNA COVID shot is a biological product that manipulates cell function and is not a traditional vaccine and the RSV shot is a monoclonal antibody product.^{11 12}

More Combination Vaccines are on the Way

There is a trend toward developing more combination vaccines. According to the CDC:

As scientists develop and test new vaccines to protect children against more diseases, more combination vaccines may become available. This will allow children to get additional protection with fewer shots.⁹

A study published in the journal The Lancet on Apr. 15, 2024 noted that combination vaccines are compelling because they could substantially increase adherence to vaccination schedules through easier delivery and greater acceptability from caregivers, health-care providers, and vaccine recipients.” Additionally, combination vaccines are also “naturally attractive to those conducting immunisation programmes because they are easier, quicker, and cheaper to administer, with few errors and decreased syringe and vial disposal requirements.”¹³

A recent article on the website of Gavi, The Vaccine Alliance, the largest distributor of childhood vaccines in the world, noted… “Childhood immunisation schedules are becoming increasingly crowded, expensive, and unsustainable. Combination vaccines could be the solution.”¹⁴

In other words, combining vaccines is more efficient in terms of logistics and cost control for those delivering and administering the vaccines. Creating more efficiency in this process would also likely have the effect of enhancing sales volume and profitability for the pharmaceutical companies that manufacture the vaccines. Interestingly, the issue of safety (to the patient) seldom seems to come up when discussing the push toward more combination vaccines or adding more vaccines to combination vaccines. Unsurprisingly, public health officials licensing and recommending vaccines and doctors administering vaccines claim combination vaccines are safe.

No Limit to Number of Vaccines One Can Safely Take?

Because vaccines are biological products that stimulate inflammatory responses in the body and carry a risk of injury or death that can be greater for some people, it is illogical to claim that giving a person one vaccine is the same as giving a person five or seven or 10 vaccines simultaneously. A 2013 report published by the Institute of Medicine, The Childhood Immunization Schedule and Safety: Stakeholder Concerns, Scientific Evidence and Future Studies, pointed out that there are outstanding questions about the safety of administration of multiple vaccines according to the federally recommended childhood vaccination schedule:

Most vaccine related research focuses on the outcomes of single immunizations or combinations of vaccines administered at a single visit. Although each new vaccine is evaluated in the context of the overall immunization schedule that existed at the time of review of that vaccine, elements of the schedule are not evaluated once it is adjusted to accommodate a new vaccine. Thus, key elements of the entire schedule—the number, frequency, timing, order and age of administration of vaccines—have not been systematically examined in research studies.¹⁵

Yet, the CDC minimizes the potential health problems associated with giving children combination vaccines, stating, “Sometimes, certain combinations of vaccines given together can cause fever, and occasionally febrile seizures; these are temporary and do not cause any lasting damage.” The agency shamelessly downplays the dangers of febrile seizures by flat out saying that while they are “scary” for parents, they are “not harmful to children.”^{9 16}

Remember, this thinking is based on the general belief by many medical and public health professionals that the more vaccines you get, the better. Vaccinologist and pediatrician Paul Offit, MD of Children’s Hospital of Philadelphia, for example, believes that theoretically  infants have the capacity to handle about 10,000 vaccines at one time. Then there’s Sten Vermund, MD, PhD, professor of public health, infectious disease epidemiologist and pediatrician at Yale Medicine in New Haven, Connecticut, who says, “Theoretically, there’s not a maximum number of vaccines you can get at the same time if you’re willing to have sore arms.”^{17 18 19}

On the medical website MedicineNet, Edmond Hooker, MD, DrPH and Melissa Conrad Stöppler, MD write:

There is an ongoing controversy in the public media about giving “too many” vaccines at one time to little children. Physicians, however, do not believe that children are at risk from “too many” vaccinations given at one time.²⁰

Ana Weil, MD, MPH, researcher and infectious disease specialist with UW Medicine in Seattle, concurs, saying… “We have no reservations from a medical standpoint. There’s no upper limit to how many you can get at one time.”¹⁹

There’s no limit to how many of these biological products a human being can safely take all at once? Even a child? Really?

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