EEight members of the New York Yankees organization who have been fully vaccinated against Covid-19 have tested positive for the coronavirus this week. And this news has led a lot of people to say, wait what?
Below, STAT describes what we know about the cases and some of the factors that may have contributed to the cluster.
What do we know so far?
Third baseman Phil Nevin said on Sunday he experienced symptoms and tested positive for Covid-19. (He had recovered on Thursday, chief executive Brian Cashman said.)
The team quarantined people who had had close contact with Nevin and expanded its testing program, which revealed seven more asymptomatic cases on Thursday, when shortstop Gleyber Torres became the eighth person – and the first player (the other seven were coaches and support staff). – to test positive.
All eight people had received the Johnson & Johnson Covid-19 vaccine and were considered fully vaccinated.
What does this mean about breakthrough infections and vaccines?
Overall, Covid-19 vaccines have been shown to be very effective in preventing disease, and even more so in preventing worst outcomes, such as serious illness and death. But even the best vaccines can’t block all infections, and those that still occur after vaccination are called breakthroughs.
The clinical trials that led to the authorization of the various Covid-19 vaccines generally measured their effectiveness in preventing symptomatic cases, and in its trial, the J&J vaccine in one dose was found to be 66% effective to moderate and severe Covid-19 blockade. And although studies have shown that vaccines also prevent asymptomatic infections in many cases, researchers do not have firm conclusions about their effectiveness. The hypothesis is that many asymptomatic cases go unreported without extensive and frequent testing.
Which brings us to the Yankees. Eight breakthrough infections seem like a lot, and something strange could be at play here. But it should be noted that only Nevin exhibited symptoms. It’s possible that at least some, if not all, of the other seven infections would have been missed had they not occurred in a team that undergoes regular testing.
And while we can’t know for sure, it’s possible that without vaccines, this cluster could have been worse, both in terms of the number of infections. and how sick some people got. The Yankees travel with about fifty people.
Overall, the Centers for Disease Control and Prevention reports received of 9,245 ruptures, a tiny fraction of which resulted in hospitalization or death. Over 118 million people in the United States have been fully vaccinated. The low number of breakthrough infections has been touted as a testament to the power of vaccines, which both provide protection to individuals and help reduce transmission.
But experts also point to two caveats about the number of breakthrough infections. On the one hand, a large number of people who have been fully vaccinated have not since been exposed to the coronavirus, so it is not known how many infections there would have been without this vaccination coverage. The breakthrough tally is also certainly an undercount as many asymptomatic cases go undetected – unless, of course, they occur in an environment where testing is widespread and frequent, such as on a professional sports team.
Two more points: As of Friday, the CDC will only report breakthrough infections that lead to hospitalization or death because these are “of the greatest clinical and public health importance.” The Yankees’ cases, of course, have not reached that level.
And Torres, the shortstop, had Covid-19 last year, indicating his case is both a breakthrough infection and a reinfection. Scientists believe re-infections remain rare, although, since second infections are generally considered mild or asymptomatic (similar to rupture infections), experts also don’t have good estimates of how often they occur. But since Torres was asymptomatic, his case was what experts expect from most re-infections.
How did it happen?
The team said they were conducting contact tracing and officials from the New York State Department of Health and CDC were in contact with the team. So far, it is not known how this transmission occurred.
Two of the most pressing questions we can think of:
Where did the spread start?
Essentially, was this a very common event in which someone – likely an unvaccinated person – transmitted the virus to all eight people? This is a probable explanation. The SARS-CoV-2 coronavirus is particularly adept at transmitting in crowded indoor environments, so maybe someone who was spreading a lot of the virus got in touch with the team, and that’s how this outbreak came about. is produced. The Yankees have passed the 85% threshold of players and staff vaccinated which allowed them under league and union rules to relax some distancing and masking requirements.
It is also possible that some of the transmission occurred among the eight people who tested positive, although this appears to be a more rare event. Even if a vaccinated person contracts the coronavirus, it appears that they are generally less contagious to others than a person unvaccinated with Covid-19 – especially if they are asymptomatic. This may be because the vaccine reduces the amount of virus these people can shed and also shortens the window during which they are contagious.
Was there a variant involved?
Some variants of the coronavirus – most notably B.1.351, which first appeared in South Africa but circulated at low levels in the United States – cause rupture infections at higher rates than other forms of the pathogen. Vaccines still prevent many cases and retain their overall protection against serious illness and death. But the injections seem to lose some of their effectiveness in warding off mild or asymptomatic infections, and may not be as effective in preventing people with contagious infections from spreading the virus.
Major League Baseball work with a Salt Lake City lab for its testing and sequencing efforts, so that we may eventually get more information on this matter. The sequencing data could also reveal whether all eight people were infected during the same event or independently of each other.
Does that mean the CDC was shortsighted his recommendation Thursday that fully vaccinated people do not have to wear masks in most settings?
Depending on the type of mask, face masks are generally aimed more at protecting others than yourself, which means they’re more of a tool to keep you from spitting a virus out into the world than to block the virus that is making its way to the world. you.
There were nuances in the updated CDC recommendations as well. The data indicate that the chances of an asymptomatically infected person who has been vaccinated transmitting the virus are extremely low. But CDC director Rochelle Walensky noted Thursday that if someone starts to feel sick, they should start wearing a mask again and get tested.
Still, critics of the CDC’s decision could point to the Yankees cluster as a sign that caution is in order. While many experts celebrated the CDC’s announcement, others argued that the agency was premature or that it should have linked the guidelines to reaching thresholds like a further reduction in new cases per capita or reaching a certain level of immunization coverage. (Given the variability in infection and vaccination rates across the country, some places have reached these milestones.) The problem is that with transmission still at the rate it is, and with vaccination rates too. low than they still are, people who are not vaccinated or who have not mounted a strong immune response to vaccines (such as some people with cancer live) will be more vulnerable to contracting the coronavirus than if the CDC had just waited a few more weeks.
Was it a fluke?
Not all members of the Yankees organization have tested positive this week vaccinated at the same time, so the outbreak cannot be attributed to a wrong batch of vaccine or an error in keeping the injections at the right temperature. Yet in a pandemic in which hundreds of millions of people have been infected and in the midst of a global vaccination campaign, there are going to be some strange unusual situations. Simply put, maybe something weird has happened with the Yankees.
He emphasizes how important it is to avoid drawing conclusions from a case involving fewer than a dozen people. The clinical trials that established the effectiveness of the vaccines involved tens of thousands of people and real world data that confirmed what the clinical trials concluded: the vaccines are extremely potent against Covid-19.