Experts Say It’s Unlikely Fully Vaccinated People Are Unknowingly Spreading COVID-19

• Despite the increased spread of the delta variant, experts say it’s unlikely fully vaccinated people who have an asymptomatic infection are transmitting the virus.
• Experts say that’s because vaccinated people who have contracted the coronavirus have much lower viral loads than unvaccinated people.
• Experts still recommend that vaccinated people take safety precautions when they’re in large crowds or a region with a low vaccination rate.

The rapid spread of the coronavirus delta variant has led to concerns that people who have been fully vaccinated against the disease may be unwittingly spreading it because they have an asymptomatic infection and aren’t aware of it.

However, experts say that while not impossible, COVID-19 transmission by fully vaccinated people is unlikely.

The delta variant is highly infectious and potentially more deadly than previous SARS-CoV-2 variants. It currently accounts for more than half of all new COVID-19 cases in the United States.

It’s estimated that more than 99 percent of new COVID-19 cases are among unvaccinated people.

Spread of the delta variant has been particularly swift in states with low vaccination rates. But cases of the newest variant have appeared in every state, including those with high vaccination rates.

That doesn’t necessarily mean that vaccinated people are playing a major role in spreading the disease, though.

“In virology, the hallmark of transmission is viral load,” said Dr. Bruce K. Patterson, a virologist and the CEO of IncellDx, a company designing new methods of predicting, identifying, and treating long-term COVID-19 cases.

“The more virus you have, the better chance you have of spreading it,” Patterson told Healthline. “From what we know of wild COVID (the non-variant form of the novel coronavirus), people who are vaccinated are not carrying very much viral load, so the probability of them being infectious is very low.”

Not only are vaccinated people at far less risk of contracting the coronavirus, they’re also less likely to be asymptomatic carriers of the virus or transmit it to others, according to the Centers for Disease Control and Prevention (CDC).