Asbegan to accelerate again this spring, federal data suggests the rate of breakthrough COVID infections in April was worse among boosted Americans than unboosted Americans — though death and hospitalization rates remained the lowest among boosted them.
The new data does not meansomewhat increase the risk. Ongoing studies continue to provide strong evidence of the additional protection offered by booster shots against infection, serious illness and death.
Instead, the change highlights the increasing complexity to measure the effectiveness of the vaccine at this stage of the pandemic. It comes as officials weigh key decisions on booster shots and pandemic monitoring, including whether to continue using “crude case rates” at all.
It also serves to illustrate a delicate reality facing health authorities amid the latest wave of COVID-19: Even many boosted Americans are vulnerable to catching and spreading the virus, at a time when authorities are reluctant to reimpose pandemic measures like mask requirements.
“During this wave of Omicron we are seeing an increase in mild infections – household type infections, inconveniences, colds, absence from work, not great but not the end of the world. And it It’s because these Omicron variants are able to break down 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 people feel, after the vaccination and the booster, that they’re more protected than they actually are, so they’re increasing their risk,” he said. . “That’s, I think, the main driver of those stats.”
On the CDC’s dashboard, which is updated monthly, the agency acknowledges several “factors that may affect crude case rates per vaccination and booster dose status, making it difficult to interpret the recent trends”.
The CDC had rolled out the page several months ago, amid calls for better federal tracking of watershed cases. It has now grown to encompass data from vaccination records and positive COVID-19 tests from 30 health departments across the country.
For the week of April 23, he indicated that the rate ofamong boosted Americans, there were 119 cases per 100,000 people. That was more than double the rate of infections in vaccinated but unvaccinated people, but a fraction of the levels in unvaccinated Americans.
This could be because there is currently a “higher prevalence of prior infection” among those who are unvaccinated and unboosted, the CDC said. More energized Americans may have now ditched “prevention behaviors” like wearing masks, leading to a slight increase.
Some boosted Americans might be more likely to seek a lab test for COVID-19, instead of relying onthat go largely unreported to health authorities.
“Home testing has become, I think, the biggest concern in developed countries that can interfere with our measurements,” the CDC’s Ruth Link-Gelles said at a conference hosted by the National Foundation for Infectious Diseases this month. last.
Some federal officials have raised the possibility of adopting an investigation – similar to those relied on by authorities in the UK – as an alternative means of tracking a “ground truth” in COVID-19 cases, although the Plans to set up such a system do not appear imminent.
“Beyond this crisis, I think the future is in random sampling. And that’s an area we’re looking at closely,” said Caitlin Rivers, senior disease forecasting team leader at the agency, at an event organized by the National Academies. Last week.
Meanwhile, federal officials are also bracing for key decisions on future COVID-19 vaccines, which could increase the odds that additional vaccines can fend off infections of the latest variants.
In the short term, CDC Director Dr. Rochelle Walensky recently told reporters that her agency was 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.
New generation of vaccines and boosters
Further down the road, a panel of outside Food and Drug Administration vaccine advisers is due to meet later this month to weigh 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 from both injections specifically tailored to the Omicron variant in addition to “bivalent vaccines,” which target a mix of mutations.
These new vaccines would take about three months to manufacture, senior 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 evolve over the next few months, but we have no choice because if we want to produce the hundreds of millions of doses that need to be available for a recall campaign, we need to start at risk in early July or even a little earlier,” said Dr. Peter Marks, the FDA’s top vaccine official, during a recent webinar hosted by the American Medical Association.
Marks said bivalent fire seemed likely to be favored, given the “wiggle room” it could provide for unforeseen variants beyond Omicron.
Vaccines that could offer even better “mucosal immunity” — actually fighting the virus where it first infects the respiratory system — are still a long way off, Marks warned.
“I think we are in a period of transition and again I will speak openly about the fact that 2022 to 2023 is a year where we have to plan to try to minimize the effect of COVID-19 with the tools we have. in hand,” Marks said during a recent event with the National Infectious Disease Foundation.
“I believe that, potentially by the 2023-2024 season, we will start to see second-generation SARS-CoV-2 vaccines,” he added later.