According to a new study published on Friday, those who have received COVID-19 immunizations can spread the delta variant within their household just as easily as people who have not been vaccinated.

People who got COVID-19 had a similar viral load regardless of whether they had been vaccinated, according to a study published in The Lancet Infectious Diseases Journal. The study also discovered that COVID-19 was contracted by 25% of vaccinated household contacts. Unvaccinated people were diagnosed with the illness in 38% of cases, reported the The Hill.

Researchers examined 621 symptomatic participants for more than a year in the United Kingdom.

The study said, “Although vaccines remain highly effective at preventing severe disease and deaths from COVID-19, our findings suggest that vaccination is not sufficient to prevent transmission of the delta variant in household settings with prolonged exposures,” The Hill reported.

The vaccine, was shown to be more effective at preventing transmission of the alpha version within the home, with a success rate of 40 to 50 percent as noted by the researchers. The qualifier “within the home” refers to the environment where the virus can most effectively spread.

“Increasing population immunity via booster programmes and vaccination of teenagers will help to increase the currently limited effect of vaccination on transmission, but our analysis suggests that direct protection of individuals at risk of severe outcomes, via vaccination and non-pharmacological interventions, will remain central to containing the burden of disease caused by the delta variant,” wrote the researchers.

The study comes as the number of COVID-19 cases have begun to fall across the United States, and the case fatality rate in Louisiana among the vaccinated remains higher compared to the unvaccinated in the state. The study also arrives just days after the Food and Drug Administration approved emergency use authorization for the Pfizer-BioNTech COVID-19 vaccine for children ages 5 – 11.