Healthcare workers likely will be offered a new COVID-19 vaccine the FDA is pushing to roll out for this fall and winter.
With the vote 19-2 at a June 28 meeting, the FDA Vaccines and Related Biological Products Advisory Committee (VRBPAC) approved “the inclusion of a SARS-CoV-2 omicron component for COVID-19 booster vaccines in the United States.”1
Healthcare workers were among the first groups to receive the original vaccine, and they are expected to be offered the new bivalent booster, along with those age 50 years and older. This has not been resolved definitively, nor has the exact omicron component that will be combined with the existing vaccines against the original strain. The FDA urged anyone who has not received their booster shots to do so immediately to build as much protection as possible before the expected surge.
As of July 23, the BA.5 subvariant of omicron comprised 82% of cases in the United States. In a steady climb to bypass all other omicron subvariants, BA.5 has reduced BA.4 to 13% of cases and BA.2.12.1 to just 5%.2
The general feeling among the panel was that something must be done, as accumulating evidence indicates these omicron subvariants — particularly BA.5 — are causing breakthrough infections in the fully immunized and those previously infected with other variants. Thus, even fully immunized healthcare workers could be vulnerable, perhaps more in the community than on the job in PPE.
The results of a recent study suggest this. Two co-authors from the CDC emphasized the findings in a blog post.
“[Researchers] found that the occupational risk of COVID-19 to healthcare personnel (HCP) can be largely eliminated using recommended prevention practices,” they noted.3 The findings also “demonstrate that exposure in family and community settings plays an extremely important role in acquisition of COVID-19 by HCP. Thus, interventions such as vaccination that provide protection in both work and non-work settings are critical for preventing COVID-19 in HCP.”
Thus, if COVID-19 continues to resurge, employee health professionals will have to reinforce the risk to healthcare workers in the community and be wary of presenteeism.
Some VRBPAC members questioned whether there was enough data to make any vaccine changes, particularly since the existing vaccines continue to be largely effective against serious illness and death.
One of the dissenting “No” votes was from Paul Offit, MD, an internationally recognized expert in virology and immunology.
“I don’t think it is fair to ask people to take a risk — with any vaccine that we get — if we don’t feel comfortable with the level of protection that we are likely to get by including omicron,” said Offit, director of the Vaccine Education Center at the Children’s Hospital of Philadelphia.
‘If We Wait ...’
This point certainly is valid, but the committee returned to the problem of whether they have any other choice given the potential threat they are facing in the fall and winter.
“This is truly a challenge, and it is science at its hardest,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research. “If we make a decision to wait until the evidence is irrefutable that we need to change, at that point this variant may have passed on and will have something else here.”
The available data from the vaccine manufacturers show they have generated immune responses, and the original vaccines are showing some signs of eroded protection.
“The current vaccines are no longer quite as protective against severe disease, particularly in older individuals, but probably also tailing off in younger individuals,” Marks noted.
The prevailing point seemed to be that targeting the most recent strain possible at the time the vaccine must be produced will at least bring human immunity that much closer to whatever descends from it. The timeline is tight, since it will take several weeks — and maybe months — to distribute the vaccine widely, even if the manufacturers are developing and testing candidates.
“I [understand] BA.4 and BA.5 may not be circulating later this fall, but by moving [now], we may at least bring the immune system closer to being able to respond to what’s circulating,” Marks said. “None of us has a crystal ball. We are trying to use every last ounce of what we can from predictive modeling and from the data that we have that’s emerging to try to get ahead of a virus that has been very crafty.”
According to Eric Topol, MD, founder and director of Scripps Research Translational Institute in La Jolla, CA, the “omicron sub-variant BA.5 is the worst version of the virus that we’ve seen. It takes immune escape, already extensive, to the next level.”
Topol, who is not a member of VRBPAC, discussed the issue in a recent blog post.4 While BA.5 is generally seen as very infectious but mild — perhaps due to the high level of vaccinations and prior infections — Topol questioned whether this will remain the case.
“With the extent of BA.5’s immune evasion, and the recent trends of lowered vaccine effectiveness vs. severe disease (from 95% vs. delta with a booster to ~80% vs. omicron BA.1 or BA.2 with a booster), it would not be at all surprising to me to see further decline of protection against hospitalizations and deaths,” Topol noted.
REFERENCES
- Marks P. Coronavirus (COVID-19) update: FDA recommends inclusion of omicron BA.4/5 component for COVID-19 vaccine booster doses. June 30, 2022.
- Centers for Disease Control and Prevention. Variant proportions. July 23, 2022.
- McDonald LC, Weissman D. Demonstrating the ability to protect healthcare personnel from COVID-19 in high-risk settings. NIOSH Science Blog. July 22, 2022.
- Topol E. The BA.5 story: The takeover by this omicron sub-variant is not pretty. Ground Truths. June 27, 2021.
Healthcare workers likely will be offered a new COVID-19 vaccine the FDA is pushing to roll out for this fall and winter. The FDA Vaccines and Related Biological Products Advisory Committee approved “the inclusion of a SARS-CoV-2 omicron component for COVID-19 booster vaccines in the United States.”
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