E.Members of the New York Yankees, who were fully vaccinated against Covid-19, tested positive for coronavirus this week. And this news has led many people to say, wait, what?
Below, STAT outlines what we know about the cases and some of the factors that may have contributed to the cluster.
What do we know so far?
On Sunday, the base’s third coach, Phil Nevin, said he had experienced some symptoms and tested positive for Covid-19. (He had recovered since Thursday, said CEO Brian Cashman.)
The team quarantined people who had close contact with Nevin and expanded his testing program, which led to seven more asymptomatic cases by Thursday, when the Gleiber Torres stop became the eighth man and first player (the other seven were coaches and support staff). ) ̵
All eight people received the Johnson & Johnson Covid-19 vaccine and are considered fully vaccinated.
What does this mean for breakthrough infections and vaccines?
Covid-19 vaccines have generally been shown to be highly effective in preventing disease and even more so in preventing the worst outcomes such as serious illness and death. But even the best vaccines can’t block all infections, and those that still appear after immunization are called breakouts.
The clinical trials that led to the authorization of the various Covid-19 vaccines usually measured how effective they were in preventing symptomatic cases, and in his trial, a single dose of J&J proved to be 66% efficient when blocking moderate and severe Covid-19. And while studies show that vaccines also prevent asymptomatic infections in many cases, researchers have no definitive conclusions about how effective they are. It is assumed that many asymptomatic cases are not reported in the absence of extensive and frequent testing.
Which brings us to the Yankees. Eight breakthrough infections look like a lot and something strange can be played here. But it is remarkable that only Nevin had some symptoms. It is possible that at least some, if not all, of the other seven infections have been missed if they have not appeared in a team that undergoes regular testing.
And while it may not be known for sure, it is possible that without vaccines this cluster was worse, as in terms of the number of infections. and how sick certain people are. The Yankees travel with about 50 people.
In general, the Centers for Disease Control and Prevention have reports received of 9,245 cases of breakthrough, a small proportion of which led to hospitalization or death. More than 118 million people in the United States are fully vaccinated. The small number of breakthrough infections is advertised as evidence of the power of vaccines, which provide both protection to individuals and help reduce transmission.
But experts also cite two warnings about the number of breakthrough infections. First, a large number of people who have been fully vaccinated have not been exposed to the coronavirus since, so it is not known how many infections they would have without this vaccine coating. Breakthrough counts are also certainly insufficient, as many asymptomatic cases remain undetected – unless, of course, they occur in an environment with widespread and frequent tests, such as in a professional sports team.
Two additional points: From Friday, the CDC will only report on breakthrough infections that lead to hospitalization or death, as they have “the greatest clinical and public health significance”. The Yankees, of course, did not rise to that level.
And Torres, the short stop, had Covid-19 last year, indicating that his case was both a breakthrough infection and a reinfection. Scientists believe that re-infections remain rare, although given that second infections are usually considered mild or asymptomatic (similar to breakthrough infections), experts similarly do not have large estimates of how often they occur. But given that Torres is asymptomatic, his case coincides with what experts expect from most reinfections.
How did this happen?
The team said it was tracking contacts, and New York City Health Department and CDC staff were in touch with the team. It is not yet clear how this show happened.
Two of the most pressing questions we can think of:
Where did the spread start?
In essence, was this a super-manifesting event during which someone – probably an unvaccinated person – transmitted the virus to eight people? This is a plausible explanation. The SARS-CoV-2 coronavirus is particularly adept at transmitting in crowded, closed environments, so perhaps someone who dumps a lot of viruses has come into contact with the team and this is how the outbreak came about. The Yankees exceeded the threshold of 85% of players and staff vaccinated, which allowed them to grant some distance and camouflage requirements under league and union rules.
It is also possible that part of the show took place among the eight people who took positive tests, although this would have seemed a rarer event. Even if a vaccinated person is infected with a coronavirus, they appear to be less contagious to others than an unvaccinated person with Covid-19 – especially if they are asymptomatic. This may be due to the fact that the vaccine reduces the amount of virus that these people can shed and also shrinks the window through which they are infected.
Was there an option included?
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 breakthrough infections with higher levels from other forms of the pathogen. Vaccines still prevent many cases and retain their overall protection against serious illness and death. However, photos appear to lose some of their power to prevent mild or asymptomatic infections and may not be so powerful as to prevent people with breakthrough infections from transmitting the virus.
Premier League Baseball work with a Salt Lake City lab for its testing and consistency efforts so we can eventually get more information on the subject. Sequence data can also give an idea of whether the eight people were infected during the same event or independently of each other.
Does this mean that the CDC was short-sighted his recommendation Thursday that fully vaccinated people should not wear masks in most settings?
Depending on the type of mask, face coatings are usually protected from others rather than yourself, which means that they are more of a tool to prevent you from shedding the virus in the world than blocking the virus that directs you.
There was also some nuance in the CDC’s updated recommendations. The data show that the chance of an asymptomatically infected person who has been vaccinated to spread the virus is extremely low. But CDC Director Rochelle Valensky noted on Thursday that if anyone starts to feel sick, they should start wearing a mask and getting tested again.
Still, critics of the CDC’s decision could point to the Yankee cluster as a sign that prudence is deserved. While many experts celebrated the CDC’s announcement, others argued that the agency was premature or should have linked the guidelines to reaching thresholds such as further reducing new per capita cases or reaching a certain level of vaccination. (Given the variability in infection and vaccination levels in the country, some sites have reached these stages.) The concern is that with transmission still at the rate it is, and with low vaccination levels as it still is, people who do not have been vaccinated who have not found a strong immune response to vaccines (such as some people with cancer survive) will be more vulnerable to coronavirus infection than if the CDC had just waited a few more weeks.
Was this an accident?
Not every member of the Yankee organization who did well this week was vaccinated simultaneouslyso that the outbreak cannot be attributed to a bad batch of vaccine or a mistake in keeping the shots at the right temperature. Still, in a pandemic in which hundreds of millions of people are infected and against the backdrop of a global vaccine campaign, there will be some strange, weirder situations. Simply put, maybe something strange happened to the Yankees.
Stresses the importance of avoiding conclusions from a case involving less than a dozen people. Clinical trials that have established the effectiveness of vaccines include tens of thousands of people and actual data that support the conclusions of clinical trials: vaccines are extremely powerful against Covid-19.