Vaccinated people who get COVID carry fewer viruses

July 2, 2021 – People who have received a COVID-19 vaccine and are subsequently infected with the coronavirus tend to have a lower viral load according to a new study published Wednesday in the New England Journal of Medicine.

This means that they are likely to be less contagious than unvaccinated people and do not transmit the virus to others as much. Additionally, researchers found that vaccinated people had a shorter, smoother course of COVID-19.

“Even when people get vaccinated and become infected, they were less likely to have an illness that causes a fever,” said Mark Thompson, a lead author and epidemiologist at the CDC. The Wall Street Journal.

“There is reason to believe that even if you are infected, you have fewer viruses to spread and infect other people,” he said.

The research team followed 3,975 health workers and first responders who underwent weekly tests between mid-December and mid-April. COVID-19 was detected in 204 participants, including five fully vaccinated and 11 partially vaccinated with Pfizer or Moderna injections.

Fully or partially vaccinated participants had a 40% lower viral load than unvaccinated participants, as well as a 66% lower risk of having a detectable virus for more than a week. They also had a 58% lower risk of fever symptoms.

None of the vaccinated people who contracted COVID-19 have been hospitalized, and they all have had mild or moderate cases. They also had a shorter illness duration, with about two fewer days spent sick in bed and six days fewer symptoms.

Based on the results of the study, the researchers calculated that the vaccines were 91% effective at preventing infections in fully vaccinated people and 81% effective in partially vaccinated people.

In addition, the researchers sequenced 10 of the 16 cases found in people who were fully or partially vaccinated. They found three variant cases, all of which involved the Epsilon variant first identified in California. Study samples were collected before the contagious Delta variant, first identified in India, arrived in the United States this year, The Wall Street Journal reported.

“The vaccines are not only very effective in preventing SARS-CoV-2 infection, but can also lessen the effects of breakthrough infections,” the researchers wrote, which is “particularly important for essential and primary workers. line, given their potential for transmission of the virus through frequent closures of contact with patients, colleagues and the public.