Context Check: Vaccines

Get the latest vaccine safety guidance from CDC, including safety information for recommended vaccines, safety studies, and consultation for health professionals.

The National Network for Immunization Information (NNii) provides up-to-date, science-based information to healthcare professionals, the media, and the public: everyone who needs to know the facts about vaccines and immunization.

Our experts answer some frequently asked questions about vaccine safety.

Updated on 30 August 2021.

Immunization: The Basics

These resources for healthcare providers can help parents understand how vaccines work.

Vaccines play an important role in keeping us healthy. They protect us from serious and sometimes deadly diseases — like haemophilus influenzae type b (Hib) and measles. It’s normal to have questions about vaccines. We work with scientists and doctors to answer your questions and provide the information you need to get vaccinated. In this section of the site, you’ll find the answers to common questions like:

The COVID-19 vaccines are our best hope to end the pandemic. Scientists, researchers and volunteers worked together across borders to create them and save lives. Learn more about how they work and what you need to know.

COVID-19 is a disease caused by a new type of coronavirus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus was first detected in Wuhan, China, in December 2019 and has led to a Pandemic, announced by the World Health Organization on 11th March 2020.

Everyone should get a booster dose after completing their primary COVID vaccination series.

An official website of the United States government

Ad Council – It’s Up to You – Get Vaccine Answers Learn More THE CONVERSATION: Black Health Care Workers & W. Kamau Bell Learn More March For Science – Let’s get FACTSinated – Youtube Series Learn More COVID-19 Vaccine And The Black Community: A Tyler Perry Special Learn More CDC – Vaccinate with Confidence! Learn […]

Before considering vaccine information on the Internet, check that the information comes from a credible source and is updated on a regular basis

You can't trust everything you read, and it's important to apply that rule of thumb whenever you hear or read about immunizations or vaccine safety.

The first, if limited, numbers released by the city indicate very low infection, hospitalization and death rates for those who got their shots. But that didn’t stop hundreds from protesting vaccination requirements for municipal workers.

What part did his, now retracted, 1998 study on the link between autism and vaccines play on measles outbreaks and the modern anti-vaccination movement?

A doctor who first suggested a link between the MMR jab and autism acted unethically, the official medical regulator finds.

In the second part of a special BMJ series, Brian Deer reveals a secret scheme to raise huge sums from a campaign, launched at a London medical school, that claimed links between MMR, autism, and bowel diseaseJohn Walker-Smith, professor of paediatric gastroenterology, hurried to Malcolm ward on the sixth floor of the Royal Free Hospital, London, with what any doctor would think was bad news. An 8 year old boy, admitted for five days of investigations, had been provisionally diagnosed with Crohn’s disease. But when the child’s mother—here anonymised as “Mrs 2”—years afterwards recounted what happened, she seemed pleased to have received information she expected and made it sound as if Walker Smith was glad too. “He skipped into that room like a 2 year old,” she told me. She remembered he said: “[Mrs 2], you were right.”Brightly painted with murals, Malcolm ward was Walker-Smith’s. It came with his employment contract. Exactly one year previously, in September 1995, he had been lured to the Royal Free with many perks, of which this was one. Previously the hospital had no children’s bowel service, but with him it had a chance of the best. The initiative to recruit him, however, had not come from management. It came from an academic researcher in the gastroenterology department: a former trainee surgeon, Andrew Wakefield.1 He wanted Walker-Smith, who would bring access to children’s gastrointestinal tracts, to help him prove a personal theory. This was that Crohn’s disease was caused by persisting measles virus infections2—most notably, he came to suggest, from vaccines.3“You used to hear Wakefield’s people talking about how they would win the Nobel Prize for this,” remembers Brent Taylor, the Royal Free’s head of community child health, who frequently clashed with the pair. “The atmosphere here was …

There has been enormous debate regarding the possibility of a link between childhood vaccinations and the subsequent development of autism. This has in recent times become a major public health issue with vaccine preventable diseases increasing in the community due to the fear of a 'link' between va …

COVID vaccines are approved for children 12 to 17. Also: importance of vaccination, how to get vaccinated, have a positive vaccination experience, side effects, protect unvaccinated children, kids, youth

The History of Vaccines explores the role of immunization in the human experience and examines its continuing contributions to public health

Polio vaccines are vaccines used to prevent poliomyelitis (polio).[2] Two types are used: an inactivated poliovirus given by injection (IPV) and a weakened poliovirus given by mouth (OPV).[2] The World Health Organization (WHO) recommends all children be fully vaccinated against polio.[2] The two vaccines have eliminated polio from most of the world,[3][4] and reduced the number of cases reported each year from an estimated 350,000 in 1988 to 33 in 2018.[5][6]

CDC's Vaccines and Immunizations web site HOME PAGE.

It seemed virtually inevitable that I would be thrown out of AutismOne, a yearly conference that has been accused of being a hive of anti-vaccine sentiments, bad science, scaremongering and worthless products. The conference has, after all, ejected several science bloggers who have previously attended, as well as a…

Anna Russell writes about efforts to counter misinformation about the COVID-19 vaccine in the United Kingdom.

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COVID-19 vaccines protect against COVID-19. Get safety info and more.

Addressing misinformation and countering vaccine hesitancy features prominently in a political declaration launched at the United Nations General Assembly, as countries pledged to “work together as one” to defeat the pandemic, and help people and the planet to recover better. 

The people inviting you to ignore the serious and potentially long-term impacts of Covid won't be there to console you as you cope for years to come.

Since the beginning of the COVID-19 pandemic, blood clotting has been identified as a side effect of SARS-CoV-2 and later as an extremely rare side effect of some COVID-19 vaccines. University of Utah Health answer questions about the association of blood clots with COVID-19 and certain vaccines.

In response to the COVID-19 pandemic, several vaccines were developed and rolled out at unprecedented speed, and notwithstanding this rapid pace of development, the results from initial clinical trials involving tens of thousands of adult subjects generally indicated that most vaccines were remarkab …

Using the Drug ivermectin to treat COVID-19 can be dangerous and even lethal. The FDA has not approved the drug for that purpose.

Learn more about the drug ivermectin, including the conditions it treats, what side effects it may have, and whether it’s approved to treat COVID-19.

Thousands worldwide have taken ivermectin to fight Covid. But what's the evidence?

Scientific Reports - More than 50 long-term effects of COVID-19: a systematic review and meta-analysis

Months after illness clears, many say symptoms like fatigue, loss of smell or taste and "brain fog" persist.

The medical community must find answers for those suffering from long Covid. They are running out of time and hope

People with long Covid face an uphill battle convincing skeptics their malady is real – but discrediting uncommon conditions is hardly a new phenomenon

Some Covid-19 patients continue to experience symptoms such as buzzing sensations and shaking months after their initial diagnosis. Their cases are gaining more attention among long Covid advocates and some doctors.

Many people with long COVID feel that science is failing them. Neglecting them could make the pandemic even worse.  

Vaccines.gov helps you find clinics, pharmacies, and other locations that offer COVID-19 vaccines in the United States.

Coordinates: 40°45′01″N 73°58′21″W / 40.75028°N 73.97250°W

Inaccurate posts about the Pfizer vaccine's protection against Omicron took the drug company's boss out of context.

Lots of products advertise protective qualities but not all of them are backed by science

Health officials say it's important to improve the fit of face masks and their filtration, going beyond old, loose, cloth face coverings.

Here's the face mask that could end the coronavirus pandemic.

When Kansas issued a mask mandate, 81 counties opted out. Researchers found coronavirus infection rates rose sharply in the opt-out counties, while falling in those that required masks.