Just as “COVID-19” became a household term when it was designated as the name of the disease caused by SARS-CoV-2, terms like “Delta variant” and “omicron variant” have since become buzzwords, hearkening variations in the virus and new waves of infections.
Yet, even as countries and local jurisdictions have adopted, rolled-back, and re-implemented public health measures to adapt to changing infection rates and scientific evidence, one thing has not yet changed—the composition of the COVID-19 vaccines.
As healthcare providers and public health officials continue to battle the Omicron variant, many are wondering whether and when an updated vaccine will be necessary.
Hana M. El Sahly, MD, a professor at the Baylor College of Medicine, told Contagion that the good news is that the current vaccines have held up well.
“The current vaccines continue to provide significant protection against severe disease caused by all the variants that have emerged to date,” El Sahly, who chairs the Food and Drug Administration’s Vaccines and Related Biological Products Advisory Committee (VRBPAC), said.
In March, the Centers for Disease Control and Prevention (CDC) reported that, while hospitalizations were up across the board due to omicron, adults who were unvaccinated were 12 times more likely to be hospitalized than people who were vaccinated and boosted.
In an April press briefing, Pfizer CEO Albert Bourla, PhD, and other pharmaceutical industry executives discussed the potential for updated vaccines. Bourla said his company has the capability to quickly develop vaccines that would be effective against particular variants, but he said that is not necessarily the goal.
“It’s easy to do something only against omicron,” he said. “What scientifically and technically is more challenging…is to be effective against everything known so far, so we don’t have different vaccines for different variants.”
He said investigators at his company are currently trying to figure out the most effective path forward, after which they will make an application to the FDA and European Medicines Agency to produce an updated vaccine.
El Sahly said it is reasonable to expect that a vaccine designed to stop omicron infections would have higher antibodies against omicron and its related variants.
“But the question would be: what would the incremental benefit be at a population level in terms of prevention of COVID-19 deaths and critical disease?” she said.
More and more people in the United States and elsewhere have been vaccinated, infected, or both, and she noted that data from the US, United Kingdom, and South Africa suggests that background population immunity is lowering morbidity and mortality rates from COVID-19.
“Whether a new variant emerges that can escape this background immunity and that of a new vaccine that uses current variants is unknown,” she said.
In a May Viewpoint article in the Journal of the American Medical Association, FDA Commissioner Robert Califf, MD, and colleagues wrote that COVID-19 will likely “circulate globally for the foreseeable future,” and that vaccination efforts would likely transition to a model similar to the flu vaccine, which is updated annually. They said officials will need to make decisions this summer about who should receive additional vaccine boosters, and about the composition of the vaccine for the 2022-2023 COVID-19 “season.”
“In the event of a major fall or winter wave, a vaccine with optimal variant coverage might facilitate significant reductions in lost productivity and healthcare utilization from both acute and chronic complications of COVID-19, including postacute COVID-19 syndrome,” they wrote.
El Sahly told Contagion that physicians with anxious patients should help by providing context.
“I would tell the physician if someone received 3 doses of vaccines, then the likelihood of severe disease is extremely low unless [the patient is] immunocompromised or frail,” she said. “Also, a previous infection is a ‘boost’ of sorts to our 2/3/4 doses of vaccines previously received, and this information should be shared to help with the anxiety of some patients.”
She said it is important that patients—and healthcare professionals—understand that the goal of the vaccine is not so much to prevent all infections with SARS-CoV-2 and its variants, something she said is not likely an achievable goal with current technology. Instead, she said, the goal is to limit its consequences.
“From a clinical and public health standpoint the goal is preventing critical illness and death,” she said. “It is important to set the expectations as such.”