New data from the Centers for Disease Control and Prevention demonstrates the effectiveness of vaccines against the coronavirus, as incidents of COVID-19 fell the most among those targeted for vaccination early on in the campaign.
In a new study, the CDC found that incidents of the disease fell for every age group beginning in January, but they declined the most for those aged 65 and older. Cases fell 79% from December to May, emergency room visits fell 77%, and deaths fell 84%.
The study examined trends in COVID-19 cases, emergency room visits, hospitalizations, and deaths among those aged 65 and older, 50-64, and 18-49, from the beginning of the vaccination campaign in December through early May.
The data for hospitalization could not be broken down to examine rates among those age 65 and older but could be used to examine those 70 and older. For those aged 70 and older, hospitalization fell 78% during the study period. They dropped 58% for those aged 50-69 and 35% for those aged 1`8-49.
“Comparing the 2-week pre-vaccination period with 2 weeks in late April, declines were significantly greater among older adults, who had higher vaccination coverage, than among younger adults, who had lower coverage,” the CDC said. “These age-stratified results provide ecologic evidence of the likely contribution of vaccination coverage to reducing COVID-19 outcomes.”
Most states initially prioritized healthcare workers and nursing home residents and staff for vaccination. By January, they had added those aged 65 and older to the list of those eligible for vaccination. By early May, according to the CDC, 82% of seniors had received at least one dose of the vaccine, as had about 63% of those 50-64 and 42% of those 18-49.
The study also raises the possibility that one dose of the vaccine may have been effective at reducing cases of COVID-19. The data in the study shows that cases began plummeting in mid-January through the end of February. By the end of February, about 55 million people in the United States had received one dose of the vaccine, but only 28 million had been fully vaccinated, according to CDC data.
The United Kingdom and parts of Canada for a time followed the strategy of getting as many people as possible vaccinated with one dose before administering the second, a policy eschewed in the U.S. A study from Public Health England found that people with one dose of the vaccine were 38% to 49% less likely to pass the virus on than unvaccinated people.