In all three versions available in the U.S., the ingredient list is more familiar — and simpler — than many people might expect.
Reported by Kenneth Miller
AMONG FOLKS HESITANT TO GET A COVID-19 VACCINE, a common source of worry is what’s in the shot. They may not believe claims that the jabs contain aborted fetal tissue or mind-controlling microchips, yet for anyone without a pharmacology degree, the actual ingredient lists — full of jawbreakingly polysyllabic substances — can be more intimidating than reassuring.
In reality, however, the three COVID vaccines available in the United States are full of surprisingly familiar stuff. For perspective, we spoke with Matthew Davis, PharmD, the antimicrobial stewardship/ infectious diseases pharmacy lead for Ronald Reagan UCLA Medical Center and the Stewart and Lynda Resnick Neuropsychiatric Hospital.
“Each of these vaccines — the Pfizer- BioNTech, the Moderna and the Johnson & Johnson — contains a single active ingredient, along with a handful of other chemicals that play supporting roles,” Davis explains. “The active ingredients are based on models that have been in development for many years. And the inactive ingredients are widely used in other medications, or as ingredients in food.”
To understand the functions of those ingredients, it helps to know how the COVID-19 vaccines work. All three train the immune system to recognize and attack the SARS-CoV-2 virus, which causes COVID.
They do this by targeting the virus’s spike protein, which enables it to enter a cell. But they take different approaches. The Pfizer and Moderna vaccines use custom-designed messenger RNA (mRNA) — a snippet of genetic code that instructs cells to temporarily manufacture SARS-CoV-2 spike protein. The patient’s immune system responds to this foreign protein by producing antibodies and other weapons that can destroy the virus itself in any future encounter. The mRNA breaks down and is eliminated from the body within a few days.
The Johnson & Johnson vaccine uses a modified and harmless version of a common cold virus (Adenovirus 26) as a vector, or vehicle, to deliver a bit of genetic code to a patient’s cells. The virus can’t replicate or cause illness; it disintegrates soon after entering the body. First, though, DNA triggers cells to produce the spike protein, which primes the immune system against SARS-CoV-2. Contrary to some assertions, neither mRNA nor viral-vector vaccines change the body’s own DNA; it’s biologically impossible, as countless lab and clinical trials have shown.
“Both of these platforms are innovative, but they’re not entirely new,” Davis says. “Before they were authorized for COVID, mRNA vaccines were used experimentally for flu, Zika virus, rabies, and cytomegalovirus, with promising results. Viralvector vaccines have been studied since the 1970s, and two have been approved [by U.S. and/or European authorities] for Ebola virus over the past decade.”
The inactive ingredients in COVID-19 vaccines, he adds, have been in use for even longer. “You’ll find them in products ranging from IV fluid to headache pills to soft drinks. In fact, there are more hard-to-pronounce chemicals in some snack cakes than there are in these shots.”
Contrary to widespread rumors, none of these ingredients appear in any COVID-19 vaccines available in the U.S.