Asbegan accelerating again this spring, federal data suggests the rate of breakthrough COVID infections in April was worse among boosted Americans than unboosted Americans — although death rates and hospitalizations remained lowest among the boosted.
The new dates do not meansomehow increase the risk. Ongoing studies continue to provide strong evidence for the additional protection that booster vaccinations offer against infection, serious illness and death.
Instead, the shift underscores that growing complexity measuring the effectiveness of vaccines at this stage of the pandemic. It comes as officials weigh key decisions about booster shots and pandemic surveillance, including whether to continue using the “raw case rates” at all.
It also serves to illustrate a difficult reality public health officials are facing amid the recent COVID-19 wave: Even many charged Americans are vulnerable to contracting and spreading the virus, at a time when Officials are wary of reinstating pandemic measures like mask requirements.
“During this Omicron wave, we’re seeing an increased number of mild infections – home infections, nasty infections, colds, absenteeism from work, not great, but not the end of the world. And that’s because these Omicron variants are able to breach antibody protection and cause these mild infections,” John Moore, a professor of microbiology and immunology at Weill Cornell Medical College, told CBS News.
“So one of the dynamics here is that after being vaccinated and boosted, people feel they are more protected than they actually are, so they increase their risks,” he said. “That’s the main reason for these stats, I think.”
In the CDC’s dashboard, which is updated monthly, the agency acknowledges that several “factors are likely affecting crude case rates through vaccination and booster dose status, complicating the interpretation of recent trends.”
The CDC launched the site a few months ago amid calls for better federal tracking of breakthrough cases. It now includes data from immunization records and positive COVID-19 tests from 30 public health departments across the country
For the week of April 23, the rate was said to beamong boosted Americans, it was 119 cases per 100,000 people. That was more than double the infection rate among those who were vaccinated but unboosted, but a fraction of the infection rate among unvaccinated Americans.
That could be because there is currently a “higher prevalence of prior infection” among those who are unvaccinated and uncharged, the CDC said. More empowered Americans may now have abandoned “prevention behaviors” like mask-wearing, leading to an upward trend.
Some boosted Americans may be looking for a lab test for COVID-19 rather than relying on itwhich are largely not reported to the health authorities.
“Home testing has become, I think, the biggest problem in developed countries that can affect our measurements,” CDC’s Ruth Link-Gelles said last month at a conference hosted by the National Foundation for Infectious Diseases.
Some federal officials have hinted at the possibility of conducting a survey – similar to the one that authorities in the UK rely on – as an alternative way of tracking a “ground truth” in COVID-19 cases, although plans to build such a system this do not imminent.
“Beyond this crisis, I think the future lies in random sampling. And that’s an area we’re looking at closely,” Caitlin Rivers, a senior official on the agency’s disease forecasting team, said at a National Academies event last week.
Meanwhile, federal officials are also preparing for important decisions about future COVID-19 vaccinations, which could increase the likelihood that additional shots can ward off infections from the latest variants.
At short notice, CDC Director Dr. Rochelle Walensky recently told reporters that her agency is in talks with the Food and Drug Administration about extending the option forto more adults.
Currently, only adults 50 and older and some immunocompromised Americans are eligible to receive a fourth dose.
Next generation vaccines and boosters
Later this month, a panel of the Food and Drug Administration’s external vaccine advisors is scheduled to meet to consider data from new booster candidates produced by Pfizer and BioNTech, as well as Moderna.
BioNTech executives told investors last month that regulators had asked to see data for both vaccines that were specifically customized for the Omicron variant, in addition to “bivalent vaccines” that target a mix of mutations.
These new vaccines would take about three months to produce, said top White House COVID-19 official Dr. Ashish Jha, told reporters.
“It’s a bit of a challenge here because we don’t know how far the virus will progress over the next few months, but we don’t have a choice because if we’re going to produce the hundreds of millions of doses that need to be available for a booster campaign we start taking the risk in early July or even a little earlier,” said Dr. Peter Marks, the FDA’s chief vaccine official, at a recent webinar hosted by the American Medical Association.
Marks said bivalent shots would likely be preferred given the “leeway” they could provide for unforeseen variants beyond Omicron.
Vaccines that could provide even better “mucosal immunity” — actually fighting off the virus where it first infects the respiratory tract — are a long way off, Marks warned.
“I think we are in a transition period and I will reiterate bluntly that 2022-2023 is a year in which we must plan to minimize the impact of COVID-19 with the resources at our disposal hand,” said Marks at a last event with the National Foundation for Infectious Diseases.
“I believe that we may see second-generation SARS-CoV-2 vaccines in the 2023-2024 season,” he later added.