What we learn from rare cases of COVID-19 in vaccinated people

Of the more than 75 million people fully vaccinated against COVID-19 in the United States by the second week of April, there were only 5,814 reports of coronavirus infections – a staggeringly low number that shows how effective vaccinations are.

Since vaccines are not 100 percent effective, some breakthrough infections were inevitable and expected. However, the Centers for Disease Control and Prevention is monitoring them closely. The study of these cases will allow help experts make sure vaccines are working as expected and understand any factors that increase the likelihood that a vaccinated person will get sick.

The CDC currently has a national database where state health departments can report any cases of COVID-19 in people who have been vaccinated. Since COVID-19 is a notifiable disease, which means every case must be reported to the CDC, the agency will eventually use another system called the National Notifiable Disease Surveillance System (NNDSS) to detect breakthrough infections. Right now, he is working to ensure that states can include vaccination history in NNDSS reports.

Almost a third of breakthrough infections reported to the CDC were asymptomatic. Only 396 people were hospitalized, and a third of this group was in the hospital for a reason other than COVID-19 – that is, the disease was not the cause of their serious illness, they just also tested positive for the virus.

“Most of them were mild or asymptomatic. This is exactly what we hoped for, ”said Tara Smith, professor of epidemiology at the College of Public Health at Kent State University in Ohio. NBC News

Two new CDC reports released today provided more information on COVID-19 outbreaks in vaccinated people. One described a nursing home in Kentucky where 90 percent of the residents and about half of the staff were fully vaccinated. After an unvaccinated employee contracted COVID-19, a total of 46 people have tested positive for the virus. Four cases were in fully vaccinated employees and 18 in fully vaccinated residents.

It is noteworthy that Kentucky The outbreak has been linked to a variant form of the coronavirus called the R.1 line. It shares a number of mutations with variant viruses first identified in South Africa and Brazil, which experts say may elude antibodies produced by vaccines in part.

Infections with the R.1 virus found in vaccinated people confirm some of these concerns, the CDC said in a report. But the vaccines still worked: Unvaccinated nursing home residents were three times more likely to be infected during the outbreak than vaccinated residents. During this outbreak, the report says vaccinations were approximately 87 percent effective against symptomatic COVID-19.

The second report tracked infections in vaccinated people in 75 nursing homes in Chicago. Of the nearly 8,000 vaccinated residents and 7,000 vaccinated employees, only 22 cases of coronavirus infection have been reported. Fourteen had no symptoms and five had only mild symptoms. None of the 22 people seem to have passed the infection on to anyone else. This shows how important high vaccination rates can be in settings such as nursing homes, the report notes. Even if a vaccinated person gets sick, they are unlikely to cause a chain of infections that can spread through the facility.

This is the key to stopping the spread of disease altogether. People who have been vaccinated can get sick, although this is very rare, but they probably won’t pass the virus on to anyone else.

Vaccinated people who have contracted COVID-19 may find the experience confusing, but close examination of the circumstances of these cases underscores how powerful vaccines are. More than half of US adults received their first dose of COVID-19 vaccine. As more and more people get vaccinated, the pool of people who will become infected with COVID-19 is steadily dwindling and less of the virus will spread throughout the community. And when levels of the virus drop, vaccinated and unvaccinated people are less likely to be exposed and less likely to contract it themselves.