With COVID-19 cases continuing and life as the world knew it feeling like an increasingly distant memory, a colleague and mentor of C. Buddy Creech, MD, MPH, told him something curious.
Explore This IssueJune 2021
“This,” she taold Dr. Creech, who’s the vaccine research program director at Vanderbilt University in Nashville, “is going to be very likely the only pandemic like this in your lifetime. So, enjoy it.”
Strange as her message was, he knew what she meant. The urgent research demands have led to a massive and stunning achievement in the science of vaccines, and there’s much to celebrate. And the blossoming of the capabilities of scientists to make highly effective and safe vaccines is reason for hope as the world moves on, said Dr. Creech, whose program participated in the development of the mRNA-based Moderna vaccine. Dr. Creech gave the Triological Society’s Joseph H. Ogura, MD, Annual Lecture during the virtual COSM meetings on April 9.
Take, for instance, the B.1.351, or South African variant, of the SARS-CoV-2 virus. As it became clear that the original vaccines were less effective against this strain, a new vaccine was developed very quickly.
“It took 42 days to make the variant vaccine,” Dr. Creech said. “From the time the sequence of B.1.351 was known and the decision was made to pursue a vaccine …, it was 42 days later that the NIH had that vaccine in hand. That’s remarkable, and it’s a game-changer for the vaccine world.”
While sounding a note of optimism, Dr. Creech noted in his presentation that there are still many issues physicians and researchers are trying to sort out with regard to the virus and the vaccines.
Difficulty in defining a COVID case. “How we adjudicate COVID-19 cases in terms of whether their severity is mild or moderate might differ from company to company or study to study, and therefore we might get different efficacy numbers,” said Dr. Creech. There are also questions regarding how much time needs to pass after vaccination for a case to be considered a vaccine failure.
Nonetheless, hospitalizations and deaths have clear definitions, and preventing those are understandably the primary goals, he said. “We may not be able to prevent sore throats or flu-like illnesses, but we should be able to prevent people going to the hospital or dying from COVID-19,” Dr. Creech said.
Skepticism about the efficacy of the Johnson & Johnson vaccine compared to others. It’s skepticism that Dr. Creech said might be overblown, because the J&J vaccine did so well in preventing the worst cases. “I don’t know that you can get much better than 100% protection against fatal COVID-19 or hospitalization due to COVID-19,” he said. “These vaccines are really good at preventing severe disease.”
The need for a second dose if you have a history of COVID. “The answer is likely no, immunologically,” Dr. Creech said. “But it’s also yes because of the rise in variants and because we need people maximally immune for this period of time where disease rates are still so high.”
Uncertainty about the percentage of the population that needs to be vaccinated to reach herd immunity. “We don’t know what that magic number is,” said Dr. Creech. “We don’t know what number we need to get to have a degree of population immunity. But we certainly have a large cadre of individuals who have been infected, and a cadre of individuals now who have been vaccinated.” At a talk Dr. Creech gave in early April, he estimated that 40% to 50% of the U.S. population was likely immune to the virus to some degree.
Questions about uncommon adverse events. Shortly after the Pfizer trial began, cases of anaphylactic reactions were reported, and researchers are still trying to sort out the reason. They could involve an allergy to the ingredient polyethylene glycol. But that might not be the cause, so the recommendation is for patients to undergo testing to distinguish true anaphylaxis. Dr. Creech said another possibility is that the reactions could be an activation of a complement cascade due to molecular aggregates that form during the thawing procedures of this ultra-cold vaccine—a “pseudo-anaphylaxis.” These cases underscore the importance of other vaccine constructs, “so that we can have alternatives for those who have true allergy,” he said.