Skipping a second dose and opting only for one dose of the vaccine triggers a weaker immune response and may leave recipients susceptible to other virus variants.

CDC Data Shows That 92% of Partially Vaccinated Americans Are Returning for Their Second Dose

Some choose to miss their second shot because of scheduling conflicts, fear of side effects, or they felt protected enough with just the first

The Anopheles stephensi mosquito is a carrier of the malaria parasite, and can infect people with the parasite when it bites them

New Research

New Malaria Vaccine Trial Reports 77 Percent Efficacy Rate

The promising results were announced following a second phase vaccine trial that included 450 children between five and 17 months old

In Myanmar, a scientist with Smithsonian’s Global Health Program examines the world’s smallest mammal, a bumblebee bat.

Secretary Lonnie Bunch on the Power of Research at the Smithsonian

We can accomplish more when we unite our robust scientific capabilities with our educational reach

After receiving a Covid-19 vaccine, many patients experience side effects, like arm soreness, headache and fever.


Experts Answer Eight Key Questions About Covid-19 Vaccine Reactions

Medical professionals weigh in on why some individuals have different responses to the shots and offer advice on what to expect

An illustration of antibodies responding to an infection by SARS-CoV-2, the virus that causes Covid-19


The Next Step in Covid-19 Vaccines May Be Through the Nose

Intranasal vaccines may help prevent transmission and hinder the evolution of new viral variants

Zipline has started to deliver Covid-19 vaccines in Ghana.


Drones Are Delivering Covid-19 Vaccines to Underserved Communities

The company Zipline is using the technology to provide medical resources to rural areas in markets around the world

The new study compared 1,131 children between 12 and 15 years old who received two doses of the Pfizer-BioNTech vaccine, and 1,129 who received two doses of a placebo.

Pfizer-BioNTech Vaccine Is Highly Effective at Preventing Covid-19 Infections in Adolescents

In a study of 2,260 children age 12 to 15, no vaccinated kids contracted the virus

Nurse Sandra Lindsay of Long Island Jewish Medical Center in Queens, New York City, received the first Covid-19 vaccine in the United States in December 2020. Here, she is pictured receiving her second dose of the Pfizer vaccine in January.

New Research

CDC Study of Vaccinated Frontline Workers Shows Covid-19 Shots Effectively Prevent Infection, Not Just Symptoms

The vaccinated group of participants saw 90 percent fewer cases than if they had not been vaccinated

AstraZeneca's vaccine is approved for use in over 20 countries.

Why U.S. Approval of the AstraZeneca Covid-19 Vaccine Is Taking So Long

An unprecedented public exchange with a data review board is the latest of AstraZeneca-Oxford vaccine’s hurdles

A vaccine passport would be a digital or paper document showing that the bearer had received a Covid-19 vaccination or, in some cases, has antibodies to the virus or recently tested negative.

Five Things to Know About Vaccine Passports

As travelers venture out, countries and states are experimenting with forms of documentation that show proof of Covid-19 vaccination

The stories of children who participated in polio vaccine tests became a constant in media coverage, appearing alongside warnings and debates.

Vintage Headlines

The Press Made the Polio Vaccine Trials Into a Public Spectacle

As a medical breakthrough unfolded in the early 1950s, newspapers filled pages with debates over vaccine science and anecdotes about kids receiving shots

The vaccine developed by the veterinary pharmaceutical company, Zoetis, was provided to the San Diego Zoo after they requested help in vaccinating other apes when several gorillas tested positive for COVID-19 in January.

San Diego Zoo's Great Apes Receive First Experimental Covid-19 Vaccine for Animals

Five bonobos and four orangutans were treated with a synthetic form of the virus

About 31 million people had been fully vaccinated in the U.S. as of Monday, March 8.


CDC Releases Guidelines for People Vaccinated Against Covid-19

The rules allow small gatherings with other vaccinated people or visits to a single household of unvaccinated people

Sandra Lindsay, an intensive care nurse with Northwell Health, was the first person known to receive the approved vaccine in the United States on December 14, 2020.


First Vial Used in U.S. Covid-19 Vaccinations Joins the Smithsonian Collections

The empty vial, a vaccination card and scrubs worn by nurse Sandra Lindsay, first to be injected, will go on view in a new exhibition in 2022

The authorization is the third Covid-19 vaccine—following Moderna and Pfizer-BioNTech's mRNA vaccines—approved for use in the United States.

FDA Approves Johnson & Johnson Vaccine, Another Valuable Tool Against Covid-19

New vaccines increase the total supply and meet the needs of different communities

Now that several Covid-19 vaccines have been shown safe and effective in adults, the producers can begin clinical trials in adolescents.


Why the Covid-19 Vaccine Rollout Will Be Different for Kids

Pfizer expects to release the first data about vaccine efficacy and safety in adolescents by this summer


The Fever That Struck New York

The front lines of a terrible epidemic, through the eyes of a young doctor profoundly touched by tragedy

Technicians at Canada's main polio vaccine supplier at the time, Connaught Laboratories, working on a step of vaccine formulation in 1955.

The Great Canadian Polio Vaccine Heist of 1959

A theft more than 60 years ago shows how sought-after scarce vaccine doses have been in past epidemics

If approved, the Johnson & Johnson vaccine could become available as soon as March.

Johnson & Johnson Applies for FDA's Emergency Use Authorization for Covid-19 Vaccine—Here's Why That Takes Time

Independent experts will review data from over 40,000 trial participants and meet on February 26 to make a recommendation

An 1802 engraving, The Cow Pock—or—the Wonderful Effects of the New Inoculation plays on the fears of a crowd of vaccinees.

History Shows Americans Have Always Been Wary of Vaccines

Even so, many diseases have been tamed. Will Covid-19 be next?