Vaccinated Americans face an extremely low risk of dying from Covid-19 or developing severe illness, and most of those who do succumb to the disease have multiple underlying health conditions, according to a study released Thursday by the Centers for Disease Control and Prevention cast as evidence that vaccines work — but which recommends high-risk patients take boosters and extra precautions.
The CDC study looked at more than 1.2 million fully vaccinated adults across hundreds of U.S. healthcare facilities between December 2020 and last October: Some 2,246 of them caught Covid-19 after getting vaccinated, and 189 faced a severe outcome like acute respiratory failure or ICU admission, including 36 who died.
Vaccinated people ages 65 and older are 3.22 times more likely to face a severe Covid-19 outcome than others, and the immunosuppressed and people with underlying health issues — including pulmonary disease, cardiac disease, chronic kidney disease, liver disease, neurologic disease or diabetes — also faced a higher risk.
All 189 patients with severe outcomes had at least one risk factor like age or an underlying health condition, and 78% of those who died had four or more risk factors.
Vaccinated people who previously caught Covid-19 were less likely to develop a severe outcome, and no one who took monoclonal antibodies faced severe cases.
The findings line up with a CDC study from September that found Covid-19 vaccines were 95% effective at stopping hospitalizations in adults 18 to 64 but just 80% effective for seniors, and a peer-reviewed December study that found vaccines waned in effectiveness for seniors after the coronavirus’ delta variant took root.
Those who took Pfizer and Johnson & Johnson’s coronavirus vaccines faced roughly similar odds of developing severe Covid-19, but Moderna vaccine recipients were less likely to face death, ICU admission or respiratory failure, the study found. Previous CDC studies have also found Moderna’s vaccine is somewhat more effective at keeping recipients out of the hospital, possibly because Moderna’s shots contain larger doses.
The authors of Thursday’s study said people who face a higher risk of severe Covid-19 due to age or health conditions should not only get vaccinated, but also receive vaccine booster shots, take extra precautions to avoid catching the virus and seek medical treatment if they’re infected. Experts have warned for months that the vaccines — while still effective at stopping severe illness in general — could wane in effectiveness for some, especially as new virus variants emerge and months pass since people took their initial doses. For some officials, the push to distribute booster shots has grown more urgent since the coronavirus’ new omicron variant overtook the United States last month and caused coronavirus infections to spike precipitously. Some early research suggests vaccines could be less effective at preventing omicron infections, but a booster dose makes neutralizing the virus more likely.
78.5%. That’s the share of Americans ages 5 and older who are partially vaccinated against Covid-19, according to CDC data.