Long-term care residents who get a fourth dose of the COVID-19 vaccine are at a reduced risk of being hospitalized or dying from the disease during an omicron-related surge, Israeli researchers say.
Investigators found a “strong association” between the receipt of a fourth vaccine dose among residents and increased protection against COVID-19 hospitalizations and deaths during the omicron surge when compared to the previous three doses administered.
They used data from nearly 44,000 long-term care residents aged 60 and up from Jan. 10 to March 31. Findings were published early Thursday in JAMA Internal Medicine.
The fourth vaccine dose offered a 34% protection rate against infection, up to 67% protection against hospitalizations and 72% protection against death.
Researchers said the findings may be of global importance, given the substantial burden associated with the omicron variant, waning of vaccine-acquired immunity and importance of protecting populations.
“Unlike prior variants, such as alpha, beta and delta, that carried approximately 10 variations in the spike protein, the omicron variant has more than 30 variations, including multiple variations in the receptor-binding domain, the main factor targeted by current COVID-19 vaccines,” researchers wrote. “The omicron variant exhibits a higher transmissibility than prior SARS-CoV-2 variants as well as the capability to evade naturally acquired and vaccine-induced immunity.”
The findings come a day after an investigation found that residents’ who received a third dose of Pfizer’s COVID-19 vaccine received a special bump in omicron immunity levels.