Now scientists are working on vaccines to fight the deadly bird flu H5N1. But these vaccines aren't easy to make. One reason is that the flu virus often mutates. So a vaccine that worked against the flu last year won't protect you very well this year.

Another problem is that it takes years of tests to make sure bird flu vaccines will work on humans without making them sick.

In 2005, a study began testing a possible bird flu vaccine on 450 people. The vaccine uses a type of bird flu that was found in Southeast Asia in 2004. Some of the early results are promising. But as of spring 2007, there is still no vaccine available for H5N1.

—When Birds Get Flu and Cows Go Mad!,
John DiConsiglio

Explain the challenges scientists face with mutating viruses and how they are trying to solve the problem.

Iwill only mark brainliest if you get it correct. read the following prompt and type your response in the space provided. examine the diagram and text: you see water all around you every day as lakes, rivers, ice, rain and snow. there are also vast amounts of water that are unseen—water existing in the ground. and even though groundwater is unseen, it is moving below your feet right now. as part of the water cycle, groundwater is a major contributor to flow in many streams and rivers and has a strong influence on river and wetland habitats for plants and animals. people have been using groundwater for thousands of years and continue to use it today, largely for drinking water and irrigation. life on earth depends on groundwater just as it does on surface water. there are rivers flowing below our feet … a myth? have you ever heard that there are rivers of water flowing underground? do you think it’s true? actually, it is pretty much a myth. even though there are some caverns, lava, and ice tubes, and horizontal springs that can carry water, the vast majority of underground water occupies the space between rocks and subsurface material. some rivers, such as the alpha river in northern florida, usa, can disappear underground during low flow periods. generally, water underground is more like water in a sponge. it occupies the space is between soil and rock particles. at a certain depth below the land surface, the spaces between the soil and rock particles can be totally filled with water, resulting in an aquifer from which groundwater can be pumped into used by people. courtesy of the u. s. geological survey is there missing or extraneous information in this diagram? are all of the details in the text relevant and accurate? explain using details from the text.