A British public health study found that protection from either of the two most commonly used Covid-19 vaccines against the prevalent Delta variant of the coronavirus weakens within three months.

For many people, cats are cuddly and curious companions, but for at least 10 percent of adults they mean itchy skin, watering eyes and sneezing. This is primarily due to a protein called Fel d 1, and scientists are using a variety of approaches to try to change it. 

Moderna Inc. filed for U.S. authorization to use the company’s Covid-19 vaccine in adolescents aged 12 through 17, potentially offering healthcare providers and pediatricians an easier-to-store shot ahead of the return-to-school season in the fall.

Pfizer Inc. will start a large study to test the company’s Covid-19 vaccine in children below 12 years and selected a dosing regime for the clinical trial.

President Joe Biden said it will be difficult for the United States to reach herd immunity, at least 75% of the population inoculated against the coronavirus, by the end of the 2021 summer.

Pfizer Inc. and partner BioNTech Se are developing a booster shot to protect against Covid-19 variants.

The U.S. Centers for Disease Control and Prevention is stepping up efforts to track coronavirus mutations and keep vaccines and treatments effective against new variants until collective immunity is reached, the agency’s chief said.

A new, highly transmissible variant of the coronavirus first discovered in Britain could become the dominant variant in the United States by March, the U.S. Centers for Disease Control and Prevention warned.

The advancing rollout of approved Covid-19 vaccines provides hope to many that existing lockdowns and social restrictions will soon be lifted, but experts suggest a “return to normal” likely will not occur until herd immunity is achieved.

The United States authorized the use of Pfizer Inc’s Covid-19 vaccine on Dec. 11, with the first inoculations expected within days, marking a turning point in a country where the pandemic has killed more than 295,000 people.