To measure vaccine efficacy, or how well a vaccine works in a controlled clinical trial, the Food and Drug Administration (FDA) first looks at the number of people who fell ill with the disease. Then the agency compares whether they received the vaccine or the placebo (a…
By readying the immune system for future health battles, vaccines protect individuals around the world from dangerous diseases. 
Viruses change all the time. That's because they copy themselves to reproduce. Think of our cells as having their own xerox machines, which the virus takes over for its own purposes. 
There isn't much data yet regarding the Covid-19 vaccines' impact on pregnant women. According to the Centers for Disease Control and Prevention, "experts believe that mRNA vaccines are unlikely to pose a risk to the pregnant person or the fetus because mRNA vaccines are not live vaccines."
Researchers are moving fast to develop vaccines to combat Covid-19. In the past, it would take years to bring a new vaccine through all the regulatory hurdles established by the Food and Drug Administration (FDA) and to approval.
According to the Centers for Disease Control and Prevention (CDC), it can take a few weeks for your body to build up antibodies and maximize Covid-19 protection after receiving the second dose of the vaccine. That's why wearing masks, social distancing, practicing hand hygiene…
The Pfizer-BioNTech Covid-19 vaccine demonstrated 52 percent efficacy in protecting against disease after the first dose, according to the clinical trial data. The Moderna vaccine demonstrated 80.2 percent efficacy after the first dose. To maximize the protection from these…
The federal government has taken steps to deliver a future vaccine for Covid-19 at no cost to individuals and families during the pandemic. This is the way vaccines have been made available to the public in previous health emergencies.
With vaccine development moving so quickly, it’s easy to understand why some people are asking whether a vaccine for Covid-19 will be safe and effective. But it is important to remember the very strict scientific and regulatory process vaccine developers must follow to bring a new product to…
Scientists have not yet figured out how much immunity (protection from an infectious disease) people have after recovering from a natural case of Covid-19, or how long natural protection lasts. Some early studies suggest that natural immunity may fade more quickly in certain people.