A study on NBA players and staff found vaccinated people with breakthrough infections may be less likely to spread COVID-19 to others

Young man receives vaccine.
Young man receives vaccine.  
  • The study was conducted in partnership with the NBA.

  • It examined nearly 20,000 viral samples from the league's occupational health program.

  • It found vaccinated people cleared their infections an average of two days faster.

A new study of NBA players, staff, and household members provides yet more evidence that fully vaccinated people who get a breakthrough case of COVID-19 may be less infectious than their unvaccinated peers.

The data, collected when the Alpha and Delta variants of the coronavirus were dominant, supports a commonly-held theory among experts.

Last July, the US Centers for Disease Control and Prevention walked back earlier guidance that had said vaccinated people need not wear masks indoors, saying they should do so in areas of the country experiencing high rates of infection. At the time, CDC Director Rochelle Walensky cited the rise of the highly transmissible Delta variant and "worrisome" new science that indicated vaccinated individuals "may be contagious and spread the virus to others."

The new study, published by the peer-reviewed New England Journal of Medicine, does not challenge that claim - researchers found that people with breakthrough infections may be just as contagious as unvaccinated people.

However, researchers found that individuals with breakthrough illnesses are infectious for a shorter period of time, reducing the opportunity for them to pass the virus onto others. What's more, previous evidence suggests vaccinated people are also far less likely to be infected in the first place, especially if they have received a booster shot.

The vaccinated have a shorter transmission window, the study found

To reach their findings, scientists partnered with the National Basketball Association and analyzed 19,941 viral samples from 173 people enrolled in the professional league's occupational health program between November 2020 and August 2021. Under the program, NBA players were subject to regular testing for COVID-19.

According to the study, vaccinated people remained infected for 5.5 days, on average, compared to 7.5 days for unvaccinated people. That's 48 hours - or roughly 36% - less time to infect others.

Researchers found no difference between those who received the two-dose Pfizer-BioNTech mRNA vaccine and the one-dose viral vector vaccine from Johnson & Johnson. (Moderna's mRNA vaccine was not assessed due to a small sample size.)

"Our work provides the most detailed information to date about how viral concentrations change in the body across the full duration of SARS-CoV-2 infection," study co-author Stephen Kissler said in a statement. Kissler is a research fellow at the Department of Immunology and Infectious Diseases at the Harvard T.H. Chan School of Public Health, which led the study.

The findings support earlier claims about vaccines

While the NBA partnership provided a steady stream of samples, it also produced a study population that was overwhelmingly young, healthy, and male, and therefore not representative of the public at large.

It was also conducted before the rise of Omicron, the latest variant of concern. While it's not yet clear whether Omicron is more infectious or virulent than Delta, more research is needed to see how well our vaccines fend it off.

Nevertheless, the findings support what Dr. Anthony Fauci, the US's top infectious disease expert, said last summer: that vaccinated people are "less likely" to spread the virus. Previous studies have also found that vaccinated people typically experience shorter, milder symptoms if they are infected, as well as a faster pace of clearing the virus, all of which points to a narrower window for transmission.

Have a news tip? Email this reporter: cdavis@insider.com


More Related News

TNT Future-Proofs Its NBA Studio Roster With Draymond Green Hire
TNT Future-Proofs Its NBA Studio Roster With Draymond Green Hire

If Charles Barkley makes good on his public avowals to step away from the Inside the NBA franchise before his contract runs out in June 2025, Turner Sports has taken out an insurance policy with its signing of Draymond Green. While there can be no replacing the media phenomenon that is Sir Charles, who has […]

Once considered risky NBA lottery pick, Suns
Once considered risky NBA lottery pick, Suns' shooting star channeling his inner Klay Thompson

Suns' third-year forward has been on a tear from the 3-point line, which has helped the Suns to the league's best record.

Cavs' Evan Mobley led all rookies in All-Star fan voting

While no first-year players were named starters, Cavaliers forward Evan Mobley led all rookies in fan voting.

Three Things to Know: It
Three Things to Know: It's an All-Star exhibition, give the people what they want

The fans voted Wiggins as a starter in an exhibition game, why would anyone have a problem with that?

Map: See if the CDC recommends indoor mask use in your county
Map: See if the CDC recommends indoor mask use in your county

Nationwide, 99.9 percent of counties are included in the indoor mask guidance.

Leave a Comment

Your email address will not be published. Required fields are marked with *

Cancel reply


Top News: Latin America