Vaccinated People can still Transmit COVID-19, but it’s Not as Common as Unvaccinated Transmission

Vaccinated People can still Transmit COVID-19, but it’s Not as Common as Unvaccinated Transmission

Those who are vaccinated can still be infected with COVID-19 but are much less likely to catch it.

COVID-19 vaccines continue to work, even when facing the highly infectious Delta variant especially when it comes to protecting against severe illness and even death. Fully vaccinated people are also less likely to contract the disease than unvaccinated people are. A recent study shows that when fully vaccinated people do contract the coronavirus, they can still transmit it.

Experts say these new results, which were published October 29 in The Lancet Infectious Diseases, should not deter people from getting vaccinated. Instead, they emphasize that wider vaccine coverage is needed to ensure that when people have an infection, they are well protected against severe cases.

Although fully vaccinated people were less likely to contract an infection, according to the study, when they did — what’s known as a breakthrough infection — they can transmit the Delta variant at a similar level as unvaccinated people. Researchers found that 25 percent of household contacts exposed to a fully vaccinated person in the household contracted an infection themselves. Of those exposed to an unvaccinated household member, 23 percent contracted an infection.

“Breakthrough infections in fully vaccinated people can efficiently transmit infection in the household setting,” wrote the study authors.

Even though the peak was similar for vaccinated and unvaccinated people, the viral load decreased faster for fully vaccinated people with a Delta infection than for unvaccinated people.

“This study confirms that COVID-19 vaccination reduces the risk of delta variant infection and also accelerates viral clearance in the context of the delta variant,” Wilders-Smith wrote.

According to an article, viral load is directly related to infectiousness. Higher viral loads are more likely to lead to transmission of COVID-19. The study results suggest that because the viral load of vaccinated people drops off more quickly, their infection may be infectious for a shorter time than for unvaccinated people. The researchers, though, didn’t look specifically at how likely people were to transmit the disease during the later stages of their infection.

About the Author

Shereen Hashem is the Associate Content Editor for Occupational Health & Safety magazine.

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