Yale Medicine Vaccine Content Center
[Originally published: Dec. 11, 2020. Updated: Feb. 21, 2022]
Note: Information in this article was accurate at the time of original publication. Because information about COVID-19 changes rapidly, we encourage you to visit the websites of the Centers for Disease Control & Prevention (CDC), World Health Organization (WHO), and your state and local government for the latest information.
COVID-19 has changed so many aspects of our lives. Yearning to get back to the way life was before, everyone is looking forward to the introduction of vaccines, a major tool in helping to move past the pandemic.
Yale Medicine is committed to providing up-to-date information on every aspect of this public health crisis. Our goal for this page, which will be updated as we add new articles and videos, is to provide a resource where you can get answers to your vaccine-related questions and also connect to other information about COVID-19.
Will you need a COVID-19 booster shot?
[Originally published: July 27, 2021. Updated: Feb. 14, 2022.]
Even though it seems like only yesterday people were calculating the date they could feel fully protected by their vaccination, boosters are increasingly being recommended for wider swaths of the population.
“The main question is how long the immunologic protection against SARS-CoV-2, which causes COVID-19, lasts,” says Albert Shaw, MD, PhD, a Yale Medicine infectious disease specialist. “And since we are learning about COVID-19 in real time, this is hard to know definitively.”
We compiled a list of booster-related questions to ask Dr. Shaw.
Johnson & Johnson and Guillain-Barré syndrome: What you need to know
[Originally published: Jan. 29, 2020. Updated: Dec. 17, 2021]
Guillain-Barré syndrome (GBS) is a rare neurological disorder in which the immune system attacks the nerves. It can cause muscle weakness and sometimes paralysis. People usually recover from it, but it can lead to hospitalization and, sometimes, permanent damage to nerve cells.
So, it’s not surprising that people have questions upon hearing that about 100 suspected cases of GBS have been identified among 12.8 million people who have received the Johnson & Johnson vaccine. While this figure is low enough to categorize the occurrences as rare, the Food and Drug Administration (FDA) attached a warning (included in fact sheets for patients and providers) in July 2021 to the Johnson & Johnson shot about the increased risk of developing GBS in the 42 days after vaccination.
In December, growing concern over another side effect—a rare number of blood clots in J&J recipients—prompted the Centers for Disease Control (CDC) to endorse a clinical preference for the Pfizer-BioNTech and Moderna shots. But the J&J vaccine is still available; the the FDA and CDC are monitoring the situation and trying to learn more about any relationship between the vaccine and the rare cases of GBS.
The link between myocarditis and COVID-19 mRNA vaccines
[Originally published: June 1, 2021. Updated: June 24, 2021]
Myocarditis, an inflammation of the heart muscle, became a trending topic this spring when the Centers for Disease Control and Prevention (CDC) reported that it is monitoring a small number of cases of heart inflammation that have arisen in young adults not long after mRNA COVID-19 vaccination. The side effect is considered important but uncommon—arising in about 12.6 cases per million second doses administered. And now the Food and Drug Administration (FDA) has announced it will place a warning on the mRNA vaccines. It’s important to note that the vaccination is still recommended for everyone who is eligible.
Herd immunity: An explanation
[Originally published: May 3, 2021. Update: May 21, 2021.]
Before the COVID-19 pandemic, the term “herd immunity” was possibly something you only heard about during flu season or during reports of upticks in measles cases—if at all.
But COVID-19 has brought that concept—when an infectious disease is less likely to spread because enough people have immunity either through exposure or vaccination—to the front of our minds. Now that we have effective coronavirus vaccines, many are wondering if and when we will reach herd immunity with COVID-19.
Manisha Juthani, MD, and other Yale experts explain herd immunity, why it matters, and what needs to happen to get there.
The Johnson & Johnson vaccine and blood clots: What you need to know
[Originally published: April 21, 2021. Updated: Dec. 17, 2021.]
Concern has been building over a small, but growing number of cases of a rare, but serious blood clotting disorder associated with the Johnson & Johnson coronavirus vaccine. As a result, in mid-December, the Centers for Disease Control and Prevention (CDC) endorsed their advisory committee’s unamimous decision to give a preferential recommendation to the Pfizer-BioNTech and Moderna vaccines.
Why vaccines may be helping some with long COVID
[Originally published: April 12, 2021.]
As more people get vaccinated against COVID-19, a surprise discovery has been that vaccines seem to provide some relief for some patients with what’s being called “long COVID.” A prominent Yale researcher is working with colleagues to launch what she predicts will be a large collaborative study to learn more.
COVID-19 vaccine comparison
[Originally published: Feb. 24, 2021; updated: Feb. 18, 2022]
As the COVID-19 pandemic enters its third year, the Omicron variant has been driving an uptick in cases in the United States primarily among people who are unvaccinated, and it is even causing infections in some vaccinated people. The good news is that COVID-19 vaccines are still expected to be effective at preventing severe disease, hospitalization, and death from COVID-19.
We mapped out a comparison of the most prominent COVID-19 vaccines.
What is it like to get a COVID-19 vaccination?
[Originally published: Feb. 10, 2021]
Two vaccines, one developed by Pfizer-BioNTech and one by Moderna, were each found to be approximately 95% effective in clinical trials and given Early Use Authorization (EUA) by the Food and Drug Administration (FDA) in December 2020. And more are on the way. So, the question remains: What is it like to get a COVID-19 vaccine?
We made a list of top concerns and asked Onyema Ogbuagu, MBBCh, a Yale Medicine infectious diseases specialist and Yale’s leading expert on COVID-19 vaccines, to share insights.
[Read the article.]
Understanding how the COVID-19 mRNA vaccines work
[Originally published: Feb. 10, 2021]
Much has been made of the fact that the Pfizer-BioNTech and Moderna COVID-19 vaccines involve Messenger RNAs (mRNAs). But how does mRNA work?
In this video, Yale experts Saad Omer, MBBS, MPH, PhD, Onyema Ogbuagu, MBBCh, and Akiko Iwasaki, PhD, explain the science behind these mRNA vaccines.
Why get the COVID-19 vaccination? One woman’s story
[Originally published: Jan. 29, 2021]
Sandra Trevino, LCSW, is a founding member of Yale’s Cultural Ambassadors program—a 10-year-old organization whose mission is to broaden community participation in clinical trials at the Yale Center for Clinical Investigation—and is doubling her efforts to help educate people about COVID-19 vaccines.
In December, the Kaiser Family Foundation released results of a survey in which more than one-quarter of Americans said they would probably or definitely not get the vaccine. Republicans, and rural and Black Americans were most hesitant, according to the survey.
“It’s a great responsibility to make sure we continue to address the elephant in the room, which is mistrust with regard to the vaccines,” says Trevino.
In a recent interview, she explained why she’s encouraging everyone to get the COVID-19 vaccine and talked about her own family’s experience with COVID-19.
[Read the Q & A.]
The Vaccine is here: Your questions answered
[Originally published: Dec. 18, 2020]
The new COVID-19 vaccine is here. But it’s still hard to know exactly what this will mean in our individual and collective lives.
For questions—big and small—we went to our foremost expert for a frank, socially distanced question-and-answer session. Onyema Ogbuagu, MBBCh, is a Yale Medicine infectious diseases specialist and the principal investigator of the COVID-19 vaccine studies supported by the Yale Center for Clinical Investigation at Yale School of Medicine, in partnership with the Yale New Haven Health System.
Vaccine basics
[Originally published: Oct. 15, 2020; Updated: Jan. 20, 2022]
We’ve been told that a vaccine that confers total protection against SARS-CoV-2, the virus that causes COVID-19, would bring a return to normalcy. In March of 2020, health experts said the timeline for an effective vaccine could be 12-18 months—yet, it seems we have one even sooner than predicted. But people are wondering: will it be safe? Will it be effective?
Yale Medicine has compiled this basic explanation of vaccines—how they work, what’s different from one kind to the next, and the approval process—and what that means for a COVID-19 vaccine.
