- The delta variant and changes in human behavior may explain why vaccines became less effective at protecting New Yorkers from infection this summer
- Researchers from the New York Department of Health used several statewide datasets to study vaccine effectiveness during delta surge
- Vaccines became less effective at preventing infection – with young adults who received Pfizer’s shot, a 25% drop in effectiveness was seen
- But the vaccine remained highly protective against hospitalization—with more than 90% effectiveness for adults aged 18 to 64 during the summer.
- Only New Yorkers over the age of 65 saw a slight drop in vaccines’ protection against hospitalization – supporting the need for seniors for booster shots
The delta variant and changes in human behavior – such as the end of masking and social distancing – may explain why COVID-19 vaccines became less effective at protecting New Yorkers from infection, a new study from the state Department of Health (DOH) found Gaya.
DOH scientists used a dataset of statewide vaccination, testing and hospitalizations to examine trends in vaccine effectiveness during New York’s Delta boom in the summer of 2021.
The results showed that there was up to a 25 percent drop in efficacy against infection for vaccines from Pfizer-BioNtech, Moderna, and Johnson & Johnson.
Despite the low effectiveness for infection, the study found that the vaccine remained highly protective against hospitalization with COVID – with more than 90 percent effectiveness for adults aged 18 to 64 during the delta surge.
Only New Yorkers over the age of 65 saw a slight drop in the vaccine’s safety against hospitalization over the summer — which the team says supports the need for booster shots in older adults.
Dr Eli Rosenberg, DOH scientist, said these data suggest that ‘ongoing safety for adults under 65 may be less of an existing concern.
New analysis from the New York Department of Health shows that delta and behavioral changes this summer caused vaccines to become less effective against COVID-19 infection, not decreased immunity. Image: Vaccinations at a church in the Bronx, New York, June 2021
From May to August, vaccines became less effective at protecting New Yorkers from coronavirus infection, with the greatest reduction seen for Pfizer vaccine recipients between the ages of 18 and 49, about 25% (top left).
Booster shots have sparked endless confusion and debate in the US in recent weeks.
The Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) recently authorized booster shots of Pfizer’s vaccine for seniors and other Americans considered to be at high risk for breakthrough COVID.
Later this week, the FDA’s Advisory Committee on Vaccines will discuss similar booster shot authorizations for the Moderna and Johnson & Johnson vaccines.
In part, these discussions are complicated because the U.S. limited data available How well the vaccines are working – and who is most at risk for a successful case.
CDC is not tracking all successful infections comprehensively, instead focusing on severe cases and specific groups, such as health workers.
As a result, data from Israel and the UK have been used in many booster shot discussions – two countries tracking breakthrough infections more closely. But the populations and vaccine rollouts of these countries are very different from those of the US.
A new study from the New York DOH helps fill in this data gap and suggests why the state saw an increase in breakthrough infections this summer.
The study – which has not yet been peer reviewed – was Posted online on preprint server medRxiv on 9 October.
“This latest study by our renowned scientists here at DOH is the largest to examine in-depth changes in vaccine effectiveness over time, all three currently authorized for use in the United States,” said New York Health. COVID-19 has been broken out by vaccines. Commissioner Dr. Howard Zucker, a senior author, in a Statement.
‘This clearly demonstrates what we’ve been saying all along – getting a COVID-19 vaccine is the best way out of this pandemic, and for New Yorkers to avoid serious illness and hospitalization. is the best way.
‘We urge all New Yorkers to be vigilant and get vaccinated against COVID-19 if you haven’t already.’
DOH scientists combined several statewide datasets with information on New Yorkers’ COVID vaccinations, test results and hospitalizations to compare vaccine effectiveness during 2021.
NY Health Commissioner Dr Howard Zucker said the new study shows that ‘getting a COVID-19 vaccine is the best way out of this pandemic’. Image: A resident of the Hebrew Home in Riverdale, New York receives his booster shot, September 2021
In addition, the researchers compared the effectiveness of the vaccine by age, by which vaccine patients received, and by the time of their vaccination.
Vaccination timing is particularly important in such studies, as some previous research on COVID antibodies has suggested that vaccines may lose their effectiveness over time.
Overall, the study included nearly 8.8 million adults living in New York—about two-thirds of whom were fully vaccinated.
The researchers focused their analysis between May 1 and August 28, 2021, during which the delta variant went from two percent of cases in the state to 99 percent of cases.
The vaccine’s effectiveness against infection declined during the delta surge – meaning that fully vaccinated New Yorkers were more likely to have a positive COVID test during this time than they were earlier in 2021.
For those who received the Pfizer vaccine between the ages of 18 and 49, the vaccine’s effectiveness against the infection declined by 25 percent during the delta increase.
There was a 19 percent drop in effectiveness for Pfizer recipients aged 50 to 64, and a 14 percent drop for Pfizer recipients over the age of 65.
Moderna vaccine recipients saw a drop in similar effectiveness: an 18 percent drop for those aged 18 to 49, 14…