Some scientists think we might be rolling up our sleeves each year not just for flu shots but for Covid-19 jabs too.
Public health experts aren’t quite clear on what the future holds for Covid-19 vaccines – but some say it’s looking more and more like these shots could be needed on a yearly basis, similar to how flu shots are recommended each fall.
“In order to keep it under control, we likely will need some form of periodic vaccination. Now, whether that’s annual or every two years or every five years, we don’t really know that yet. I think that that will emerge as we gather more data,” Dr. Archana Chatterjee, dean of the Chicago Medical School at Rosalind Franklin University, said Monday.
“But I do anticipate that this will be required on a periodic basis to keep it under control,” said Chatterjee, who’s also a member of the US Food and Drug Administration’s Vaccines and Related Biological Products Advisory Committee. She added that her comments do not reflect the opinions of the committee or the FDA.
The committee is scheduled to meet April 6 to discuss the need for Covid-19 vaccine booster doses in the future, including how often they might be needed – if at all.
The FDA said Monday that representatives from the US Centers for Disease Control and Prevention and the National Institutes of Health also will participate in the meeting.
The meeting is intended to assist the FDA in developing a “general framework” that will inform when further Covid-19 vaccine booster doses might be needed and what might warrant updating the makeup of vaccines to target specific coronavirus variants.
No official vote is planned, and there will be no discussion of authorization or approval for any specific products.
“As we prepare for future needs to address COVID-19, prevention in the form of vaccines remains our best defense against the disease and any potentially severe consequences,” Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said in a news release Monday.
“Now is the time to discuss the need for future boosters as we aim to move forward safely, with COVID-19 becoming a virus like others such as influenza that we prepare for, protect against, and treat,” Marks said. “Bringing together our panel of expert scientific external advisors in an open, transparent discussion about booster vaccination is an important step to gain insight, input and expert advice as we begin to formulate the best regulatory strategy to address COVID-19 and virus variants going forward.”
‘It’s heading towards this vaccine becoming an annual vaccine’
The day before the FDA announced the meeting date, former FDA Commissioner Dr. Scott Gottlieb said he also thinks Covid-19 vaccines may become an annual shot.
“I think it’s heading towards this vaccine becoming an annual vaccine, at least for the foreseeable future, until we really understand the epidemiology of this disease and understand whether this coronavirus starts to recede into the background like the four circulating strains of the coronavirus that we’ve become accustomed to have,” Gottlieb, a Pfizer board member, told Margaret Brennan on CBS “Face the Nation” on Sunday.
Coronaviruses that are known to infect humans were first identified in the 1960s, and among them are four circulating strains that cause common colds. The other human coronaviruses are Middle East respiratory syndrome, or MERS; severe acute respiratory syndrome, or SARS; and SARS-CoV-2, the virus that causes Covid-19.
When it comes to Covid-19, “I think this is really a six-month vaccine in terms of providing really meaningful protection against symptomatic disease and infection,” Gottlieb said. “And this is likely to become an annualized vaccine for the majority of Americans.”
It remains clear that the coronavirus that causes Covid-19 is not disappearing any time soon. Rather, some researchers say we can expect the pandemic to transition into an endemic phase. Endemic means a disease has a constant presence in a population but is not affecting an alarmingly large number of people, as typically seen in a pandemic.
So SARS-CoV-2 could still circulate, but hopefully it would be at low enough levels that it no longer overwhelms our health systems.
“In terms of the virus itself, what we can expect is that it’s not going to go away, that we will have recurrent surges and that our immunity will wane over time,” said Dr. Abraar Karan, an infectious disease fellow at Stanford University.
Several studies have shown that the immunity against Covid-19 elicited by the Pfizer/BioNTech, Moderna and Johnson & Johnson vaccines can wane over several months, especially among older adults who might have weaker immune systems.
“So the combination of our immunity waning and then the virus mutating means that future surges are unpredictable,” Karan said.
“We will need boosters again in the future – probably later this year is my guess – and they will need to be tweaked more closely to what the most recent strain is that’s spreading,” he said. “We do this, obviously, annually for flu. … But flu has a more predictable seasonality to it.”
What a future booster might look like
Future Covid-19 boosters might be completely different formulas from the vaccines that are administered now.
Some companies, including Pfizer and Moderna, are developing variant-specific vaccines that could target whatever variant of the SARS-CoV-2 virus is circulating when the booster might be needed.
Pfizer and Moderna have said they are working on a vaccine that would specifically protect against the Omicron variant, even though it’s not clear whether one is needed.
Pfizer CEO Albert Bourla said the company is also hoping to make a vaccine that will protect against Omicron as well as all other variants of SARS-CoV-2.
The goal is to create “something that can protect for at least a year,” Bourla told CBS this month. “And if we are able to achieve that, then I think it is very easy to follow and remember so that we can go back to really the way [we] used to live.”
Moderna and the biotechnology company Novavax also are working on two-in-one combination vaccines that can offer protection against both flu and Covid-19.
“Our goal is to be able to have a single annual booster – so that we don’t have compliance issues where people don’t want to get two to three shots a winter, but they get one dose where they get a booster for corona and they get a booster for flu and RSV, to make sure that people get their vaccines,” Moderna CEO Stéphane Bancel said at the World Economic Forum in January of a single vaccine for Covid-19, influenza and respiratory syncytial virus, a common virus that causes cold-like symptoms.
There could be a benefit to having a combination Covid-19 and flu vaccine, Chatterjee said.
“There are logistical benefits: The number of injections that need to be given is reduced; the benefits to the storage facilities that are delivering, administering these vaccines don’t have to store as many vaccines because they’re in a combined form,” she said.
But she added that there are some limitations, as well.
“There are a couple of different issues with combinations. You have to make sure that they work together, which doesn’t always happen. Sometimes, the vaccine components can interfere with each other, and you don’t get as good an immune response as you would like,” Chatterjee said. “And then there’s the safety factor. As you add more vaccines together, often you get more reactions, particularly local reactions.”
Another element: Will enough people even take the vaccine?
The pace of Covid-19 booster administration in the United States has slowed. Although more than 65% of the US population is fully vaccinated with at least their initial series, only 29% of the population has received a third dose.
The uptake of flu shots in the United States also has room for improvement.
Traditionally, about half of adults get their flu shots. During the 2020-21 flu season, among adults 18 an older, coverage was 50.2%, according to CDC data.
Chatterjee said a combination flu and Covid-19 vaccine might improve that uptake.
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“I would assume – and this is an assumption on my part – that those who currently get the influenza vaccine would probably continue to get them, and if they were offered as combinations, most of them would probably take the combination vaccine,” Chatterjee said.
“And then for those who received the Covid vaccine, perhaps they will be encouraged to take the combination also, so that they get double protection against flu,” she added. “Am I optimistic? I am that we will get better coverage for both types of viruses through combination vaccine.”
CNN’s Jen Christensen contributed to this report.
