Pfizer announced Thursday that its vaccine candidate for respiratory syncytial virus was 85.7% effective in preventing lower respiratory tract illness in older adults.

Public health experts tell ABC News which vaccine is used to protect against polio and why most Americans are unlikely to be infected with the disease.

Children in London are being offered polio vaccine boosters after sewage samples with the virus were found in multiple areas across the city.

New York health officials said a patient was infected with vaccine-derived polio. Here's what that means.

A federal advisory panel says Americans 65 and older should get newer, souped-up flu vaccines

The vaccine will mainly be available to healthcare workers and lab personnel.

Thousands of people have marched through the Czech Republic’s capital to protest against compulsory COVID-19 vaccination for certain groups and professions

The data comes from a large-scale analysis in South Africa.

An independent CDC advisory panel will vote Tuesday on whether to recommend Pfizer's COVID-19 vaccine for children ages 5 to 11 in the U.S.

The Pentagon is grappling with new vaccine orders.

The vaccination rate nationwide is down to the lowest level since January.

Republican Sen_ Ron Johnson, of Wisconsin, questioned the need for widespread COVID-19 vaccinations, saying in a radio interview “what do you care if your neighbor has one or not?”

The CDC found a more than 80% decline in HPV infections nationally.

The Pfizer and Moderna vaccines are safe and effective in pregnant and lactating women and those women are able to pass protective antibodies to their newborns.

A majority of small businesses aren’t requiring their employees to get tested for the new coronavirus or get any COVID-19 vaccines, though the health care and hospitality industries are ahead of the curve on the requirement

Health officials are girding for questions about which one is best.

Clinical studies showed that the one-shot vaccine provides strong protection against COVID-19, including 85% effectiveness against severe illness and preventing 100% of hospitalizations and death.

Peru’s foreign minister has resigned amid an uproar over government officials being secretly vaccinated against the coronavirus before the country recently received 1 million doses for health workers facing a resurgence in the pandemic

The British government will begin a new trial to test mixing different types of COVID-19 vaccines, in which participants will receive one dose followed by a second booster shot of a different vaccine.

Denmark’s government is developing a digital passport that would show whether people have been vaccinated against the coronavirus

Health officials attempting to eradicate polio say they are being forced to suspend their mass immunization efforts amid the surging coronavirus pandemic

An Illinois sheriff's office investigating a pediatrician who killed himself last year says tests have revealed several of his former patients lack immunity to diseases against which they or their parents believed they had been vaccinated

One-third of parents are delaying immunization

An Illinois pediatrician who died by suicide last year may have forged patient's vaccination medical records, according to investigators.