CRA Medical Director Dr. Stephan Sharp returns to help you cut through the clutter and understand what matters when it comes to vaccine science and your health.
In response to the SARS-CoV-2 pandemic, generations of research and development came to fruition with the production of two successful mRNA vaccines. The Pfizer and Moderna vaccines were the first Covid vaccines approved by the FDA, but they won’t be the last. More vaccines are coming, including what we now know as “traditional” vaccines, or protein subunit vaccines in medical vernacular. In fact, we are about to begin working on a new clinical trial for these “traditional” vaccines, and I’d love to tell you about why. But before we move forward, let’s take a quick look back.
Our story begins in 10th Century China, with an early practice to protect patients from Smallpox called “variolation,” and later termed “inoculation.” Smallpox (variola), forms pustules (pox) on the skin, and is less lethal when initially infecting the skin rather than inhaled into the lungs. The contents of a pustule were used to infect the skin of a recipient, which stimulates an immune response that usually provides protection from Smallpox. This early method isn’t perfect, because sometimes it causes an infection.
This practice made its way to England in 1714. By 1798, Edward Jenner, who is known as the father of modern vaccines, proved he could effectively and more safely prevent Smallpox by injecting Cowpox, which is benign to humans, thus inventing vaccination.
Read More: New Pediatric COVID Vaccine Trial Looking for Child Participants
Scientists continued to innovate the process by creating vaccines from viruses that could infect humans. They did this by creating weakened versions of the virus in animals that could not contract the disease in question, which produces an “attenuated” version of the disease. Subsequent innovations sustained the immune-stimulating properties while killing the virus itself, thus developing protection with less risk.
The next big step was to find a target that the human immune system identifies as foreign, like a protein on the surface of the virus microbe or a toxin that the microbe creates. This led us to the vaccines that many of you grew up with. It’s like showing a wanted poster to your immune system, and it has no risk of causing the disease.
The latest advancements are the mRNA vaccines that train our own cells to make the surface protein that protects us against viral invaders. While the mRNA vaccines have the advantage of being quicker to update, the older surface subunit vaccines have an edge on the newer versions. For one, they are sturdier. mRNA vaccines are delicate, and they must be stored and transported at temperatures ranging from -20ºC to -70ºC (-4ºF to -94ºF) limiting their use considerably. This makes mRNA vaccines harder to transport to parts of the world that lack extremely sophisticated infrastructure. And, of course, some people want the old “tried-and-true” versions. So having a variety of options remains a good idea.
We will soon begin our second clinical trial of a protein subunit Covid vaccine in children < 12 years of age, and I hope you will consider volunteering with your child. Not just for the health of your own family, but for the millions worldwide who still need a COID-19 preventative measure. We will be looking for healthy kids who have not yet received a Covid vaccine.
Read more about our pediatric COVID-19 vaccine research