A Closer Look: Carrying the Legacy Forward
“That's going to take a new generation of people to create that, but I think that we have to stop sitting around and relying on the past and we have to have people who are able to think differently ... Maybe there are immunities that exist outside of antibodies and cells and cytokines. There may be other mechanisms that we don't know about.” – Dr. Maurice Hilleman
Dr. Maurice Hilleman is the most accomplished vaccinologist in history. Born on August 30, 1919, at the end of the 1918 influenza pandemic, he grew up to play a central role in the development of more than half of the vaccines routinely recommended for infants today. Dr. Hilleman’s work is estimated to save more than eight million lives each year. Sadly, he passed away in 2005. However, in honor of Dr. Hilleman’s August birthday, we wanted to take a moment to remember him and assess the state of his legacy in 2023 with a focus on three aspects of vaccines: beating pathogens, developing vaccines, and communicating science.
Beating pathogens
In 1957, as Dr. Hilleman was studying influenza virus at the Walter Reed Army Institute of Research in Washington, D.C., he realized that an influenza outbreak in Hong Kong was the start of a global pandemic. This realization made him the first person in history to successfully predict a pandemic. Immediately, he began to prepare. He got virus samples. He saved chickens. And he worked with incomparable fervor to have a vaccine ready before the virus reached the U.S. that fall. Although between 70,000 Americans succumbed to the disease when it reached the U.S., experts estimate that the death toll would have been closer to one million if a vaccine had not been developed in time. This exceptional accomplishment earned Dr. Hilleman the U.S. Military’s Distinguished Service Medal, its highest civilian honor.
Since Dr. Hilleman’s death in 2005, several pathogens have emerged for which we did not have vaccines: H1N1 influenza in 2009, Ebola in 2014, and, of course, COVID-19 in 2020, among others. We will always have novel pathogens to fight.
The "next generation" that Dr. Hilleman referred to in the above quote can be found in places like the U.S. Food and Drug Administration (FDA) where pathogen tracking and research is critical because pre-existing information and understanding better prepares us to address novel agents. This ongoing commitment to preparedness echoes Dr. Hilleman’s actions in 1957. As stated by Dr. Marion Gruber, former director of the FDA’s Office of Vaccine Research and Review, “You don't really think about regulations and rules at that time. You really think about, ‘How big is the public health emergency?’ And if you have a vaccine candidate, what are the data that you really need in order to make sure that you bring a safe and effective vaccine to the public.”
Developing vaccines
Successfully predicting a pandemic was not Dr. Hilleman’s only “first.” When it came to vaccine development, Dr. Hilleman was always searching for ways to prevent disease through vaccination. Sometimes that meant trying approaches that were novel. For example, when it came to the hepatitis B vaccine, Dr. Hilleman developed not one, but two, novel approaches to beat this virus. First, he developed a hepatitis B vaccine using blood from infected individuals to leverage the high levels of hepatitis B surface antigen found in their blood. Unfortunately, with the emergence of acquired immunodeficiency syndrome (AIDS) and the discovery of human immunodeficiency virus (HIV) in the blood of infected individuals, the source of vaccine antigen led to concerns about the vaccine’s safety. Even though the vaccine was proven to be safe and effective, its use was limited by perceptions about its safety. So, Dr. Hilleman and his team went back to the drawing board, refusing to give up on their goal of preventing a virus that can cause liver cancer. Recognizing the potential of the then-new field of genetic engineering, they leveraged the technology to create a second hepatitis B vaccine. By showing how vaccines could be made using genetic engineering, Dr. Hilleman and his colleagues opened the door for other recombinant vaccines to follow, including HPV, shingles, COVID-19 (Novavax), and the new adult RSV vaccines.
The next generation of vaccinologists emerged with the novel technologies used to develop Ebola and COVID-19 vaccines. In both cases, the vaccines deliver genetic material that leverage our own cellular machinery to produce the vaccine antigen that subsequently leads to immunity. Adenovirus-based vaccines for Ebola and COVID-19 deliver DNA, and as the name suggests, mRNA vaccines for COVID-19 deliver messenger RNA (mRNA). As the COVID-19 pandemic captivated the world, scientists like Katalin Karikó, Drew Weissman, Barney Graham, and Kizzmekia Corbett, among others, stepped out of the shadows to demonstrate that a new generation with new technologies would continue to lead us toward scientific progress.
Communicating science
In 1962, Dr. Hilleman appeared on “The Taming of a Virus,” a one-hour CBS special designed to educate the public about a new measles vaccine while also driving home the seriousness of measles infections. At the time, many people did not consider measles to be of concern. The virus was viewed as an inevitable part of childhood, like cuts and scrapes. To inform viewers that this perception was risky and inaccurate, part of the presentation showed the devastation caused by the disease in West Africa, where many young children were dying from measles. The show made a compelling case for how America could have a life-saving impact not only at home, but also abroad.
Today, portions of the public still underestimate the seriousness of diseases like measles. But, the situation is even more dire as we find ourselves in a post-truth era, characterized by a reliance on feelings and beliefs more than shared facts, and a media-saturated society, where facts compete with mis- and dis-information.
Despite these circumstances, the next generation of science communicators are leading the way — addressing not only vaccine-related concerns, but climate change, genetically modified foods, “natural” treatments and other topics in which feelings and beliefs can lead to life-threatening consequences. Like Dr. Hilleman, these are often scientists who have stepped out of the lab and onto television, social media, websites and blog platforms to ensure that people have an understanding beyond feelings and beliefs.
In sum
As stated by Isaac Newton, “If I have seen farther it is by standing on the shoulders of giants.” In the world of vaccines, we all stand on Dr. Hilleman’s shoulders.
Related resources
HILLEMAN: Influenza segment (film excerpt)
Marion Gruber: Preparing for infectious disease threats from across the globe (webpage and film)
HILLEMAN: Hepatitis B segment (film excerpt)
Inventing Our Future: The Creativity of Science (short film)
Making Vaccines: How are Vaccines Made? (webpage)
TIME 2021 Heroes of the Year - Vaccine Scientists: “The Miracle Workers” (article)