These past few months, we have seen the U.S. do a “boot and rally” on Covid. After doing a terrible job of early testing and surveillance, vaccine rollout has gone remarkably well. In the past three months, an average of two million vaccines have been administered a day. Our population is currently 35% fully vaccinated and 46% partially vaccinated as of May 12. However, we are now getting to the point where the SARS-CoV-2 vaccine supply is starting to surpass demand, thanks to the “vaccine hesitancy” phenomenon.
Hesitancy is firmest in Republican white communities in rural areas and is often clouded in misinformation. Conspiracy theories include the vaccine causing infertility, being produced from aborted fetuses (fetal stem cells), altering DNA, or having a microchip in it made by Bill Gates. Some concerns are more grounded than others, such as the speed with which the vaccine was developed and its newness. While more realistic, these concerns can be alleviated through education.
mRNA technology has been a work in progress for more than ten years. The idea of synthetic mRNA was first conceptualized in 1978 by a scientist named Katalin Karikó. After many years of research, she and other scientists made a breakthrough in the early 2000s on how synthetic mRNA could be used as a pharmacologic agent. This led to the founding of two pharma companies, one in Boston, called Moderna – cleverly named after mRNA – and the other in Germany, called BioNTech. As for the speedy process of development, while the clinical trials were truncated, all phases of clinical trials occured and due diligence followed. There was overlap between trials, as phases were done simultaneously. While this was unprecedented, there were over 70,000 adults enrolled in the three phases of clinical trials for both Moderna and Pfizer. This number is far higher than the average clinical trial. For context purposes, all phases of clinical trials for a pharmacologic agent typically have between 1,000 and 3,000 subjects.
I don’t have to debunk vaccine conspiracy theories for the average Stern student, so let me get into what vaccine hesitancy means for us. Remember when you had never heard of the term herd immunity, and now it’s something we dream of so we can get on with our lives? With vaccine hesitancy, we may never get to the threshold for herd immunity. The estimate was originally that 60-70% of Americans needed to have antibodies against SARS-CoV-2 to achieve herd immunity and for the pandemic to come to an end. It seemed achievable at first, especially with the number of people who had previous infections and the early success of the vaccine. However, the more contagious variant emerging from Britain, named B.1.1.7, changed the criteria. That variant, which first emerged in December, is thought to be roughly 50% more infectious and is now dominant in the U.S. Unfortunately, the more contagious a virus is, the higher the percentage of immunity is required to achieve herd immunity. Therefore, with this more contagious variant, epidemiologists estimate that 80-90% of Americans would need to have antibodies to achieve appropriate herd immunity. With vaccine hesitancy, we are going to fall short of that. We would need to have almost full compliance in adults. Right now, if we estimate that 30% of people are vaccinated with an additional ~30% having natural immunity (from previous infections), 60% of the population would have immunity. Ironically and sadly, we have the highest number of vaccines available to us along with the highest rates of vaccine hesitancy.
Without achieving herd immunity, we will likely continue to hear about outbreaks in areas of the United States for the foreseeable future until nearly all American adults are immune. While the rest of us have every right to enjoy our vaccination status and the reopening of our surroundings, we still need to consider what a problem people refusing to get vaccinated is. As is the case with all other vaccines, they are very much necessary to protect the immunocompromised – those who cannot get vaccinated, i.e. people with active cancer, or those who did get vaccinated but cannot mount an appropriate immune response to develop antibodies. These will be the people we need to protect in our society. Incentivizing people to become vaccinated by requiring it for sporting events, higher education, and travel will have a considerable impact on those who are resistant. Thank you NYU for leading by example and requiring students to be vaccinated to be on campus. I am very much looking forward to bumping into all of you in KMC this fall.
Photo credit: https://www.startribune.com/sack-cartoon-vaccine-hesitancy/600055142/
