Vaccinated people are quickly finding the joy in being able to go mask-less and distance-free from their loved ones again. But despite the relief that COVID vaccination should provide, some vaccinated individuals are still worried about getting infected with the coronavirus. The Centers for Disease Control and Prevention (CDC) has acknowledged that breakthrough infections can occur in fully vaccinated individuals, as no vaccine is 100 percent effective. However, new research indicates that getting vaccinated is still beneficial: The CDC has found that vaccinated people who end up getting infected with COVID will have milder disease than unvaccinated people who get infected.
A new study released by the CDC on June 7 highlights how vaccination with either one of the two available mRNA vaccines (Pfizer or Moderna) benefits fully vaccinated individuals who experience breakthrough infections after vaccination. Data from Johnson&Johnson vaccinations was not included in this study.
The researchers analyzed data from nearly 4,000 health care workers, first responders, frontline workers, and other essential workers from Dec. 13 to April 10—using nasal swabs to test for COVID and then testing positive cases to determine the amount of detectable virus in the nose, also known as the viral load, and the number of days individuals tested positive, also known as viral shedding. They also compared vaccinated people who got COVID with unvaccinated infected patients.
According to a report accompanying the study, "Several findings indicated that those who became infected after being fully or partially vaccinated were more likely to have a milder and shorter illness compared to those who were unvaccinated." The researchers concluded that fully or partially vaccinated people who got COVID spent, on average, about six fewer total days sick and two fewer days sick in bed. Individuals with breakthrough infections also had a 58 percent lower risk of developing certain COVID symptoms, like fever or chills, than unvaccinated people who got sick.
The CDC also found that fully or partially vaccinated people who get COVID might be less likely to spread the virus to others. According to the study, these participants had a 40 percent lower viral load, and viral shedding was detected for six fewer days compared to unvaccinated individuals who got infected.
"While these indicators are not a direct measure of a person's ability to spread the virus, they have been correlated with reduced spread of other viruses, such as varicella and influenza," the researchers stated in their report.
Finally, the report also confirmed the efficacy of the vaccines in preventing COVID infections. Out of the nearly 4,000 participants in the study, only 16 of those partially or fully vaccinated got infected with COVID, while 156 of unvaccinated people did. Based on those results, both Pfizer and Moderna reduce the risk of infection by 91 percent for fully vaccinated individuals. Even partial vaccination of either vaccine reduced participants' risk of infection by 81 percent.
"COVID-19 vaccines are a critical tool in overcoming this pandemic," CDC director Rochelle Walensky, MD, said in a statement. "Findings from the extended timeframe of this study add to accumulating evidence that mRNA COVID-19 vaccines are effective and should prevent most infections."