DOH study: Vaccine protection drops over time

ALBANY — Authors of a state Health Department study of COVID-19 vaccines say all three approved vaccines provide protection against hospitalization, though vaccine recipeints over the ages of 65 show a loss of immunity over time.

Released Monday, the study included 8.8 million New York residents ages 18 and older and analyzed changes in effectiveness by age, the type of vaccine they received and when they were vaccinated. Those included in the study were vaccinated between January and April and examined their levels of newly diagnosed infections and hospitalizations from May to August. That data was then further compared to people who never received a vaccine.

“The findings of our study support the need for boosters in older people in particular, and we encourage them to seek out a booster shot from their health care provider, pharmacy or mass vaccination site,” said Dr. Eli Rosenberg of the Department of Health and lead author of the study. “We saw limited evidence of decline in effectiveness against severe disease for people ages 18 to 64 years old.

While we did observe early declines in effectiveness against infections for this age group, this appears to have leveled off when the Delta variant became the predominant strain in New York. Together, this suggests that ongoing waning protection may be less of a current concern for adults younger than 65 years.”

The study found that Pfizer’s vaccine effectiveness against hospitalizations for people 65 and up dropped from May to August from 95% to 89.2% while Moderna dropped from 97.2% to 94.1% and the Johnson & Johnson dropped from 85.5% to 82.8%.

The drop in efficiency for Pfizer’s vaccine for newly reported infections was 24.6% for people between 18 and 49 years old, -19.1% for the 50-64 age group and -14.1 for 65 and up, the study said. Moderna users saw declines of up to 18% for 18 to 49-year-olds, -11.6% for 50 to 64-year-olds and 9% for those 65 and up. The Janssen vaccines saw a 19.2% decline in the 19-49 age group, -10.8% for those 50-64 and -10.9% for those 65 and older.

“(Vaccine effectiveness) declines by time-cohort were not offset in calendar time by approximately one-month, which would have suggested immunologic waning,” the study states. “However, trends in VE were highly inversely-correlated with increasing Delta variant prevalence and plateaued for persons 18-64 years during the period in which Delta exceeded 85%.”


The rate of new confirmed cases of COVID-19 has slowed slightly in Chautauqua County, according to weekly information released this morning by the health department.

From Oct. 3 to Oct. 9, there were 433 new cases of the virus along with three new virus-related deaths. There are currently 331 active cases, 33 people with the virus in the hospital and 700 people in quarantine. To date there have 12,612 total confirmed cases, 12,013 recoveries and 192 virus-related deaths.

During the week ending Oct. 2, there were 579 new cases; the week ending Sept. 25 there were 523; the week ending Sept. 18 there were 491; the week ending Sept. 11 there were 413; the week ending Sept. 4 there were 285; the week ending Aug. 28 there were 270; and the week ending Aug. 21 there were 113.

The county’s week-over-week decline in cases comes at a time when the number of new cases nationally has decreased 44% from mid-September, according to a Sunday report by CNN.

Since Aug. 1 there have been 3,179 new cases of the virus recorded in the county. Of those, 49% have involved people not vaccinated against the virus, 15% who were fully vaccinated, 7% partially vaccinated and 30% whose vaccination status was not known.


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