Ampersand in String with PHP, MySql, HTML

Question

It seems ampersand symbol is causing problem for me some where in my flow of PHP, HTML, and MySql.

With the following database and table:

DROP DATABASE IF EXISTS testamp;
CREATE DATABASE testamp;
USE testamp;

DROP TABLE IF EXISTS acronym;
CREATE TABLE acronym(
    id               INT           NOT NULL  AUTO_INCREMENT  PRIMARY KEY,
    terminology      VARCHAR(255)  NOT NULL  UNIQUE,
    acronym          VARCHAR(255)  NOT NULL,
    index (terminology),
    index (acronym)
);

INSERT INTO acronym
(terminology, acronym)
values
 ( "United States", "US"  )
,( "Humanitarian and compassionate", "H&C"  )
;

It can be verified that "H&C" is in the database by select * from acronym where acronym like 'h%c';

Now with a .php, I give the user an input box for searching an acronym:

<input type="text" name="acronym" size="50" 
  placeholder="Enter an acronym" 
  autofocus
  onkeydown="if (event.keyCode == 13) { this.form.submit(); return false; }"
>

In case of POST, the user input is retrieved by calling a function, $acronym = test_input($_POST["acronym"]);, which sanitilizes the input

function test_input($data) {
  $data = trim($data);
  $data = stripslashes($data);
  $data = htmlspecialchars($data);
  return $data;
}

Then, the input is used to retrieve data from database:

$link = create_link() or die("create_link");
$stmt = $link->prepare(
    'SELECT acronym, terminology FROM acronym WHERE acronym like ? ORDER BY acronym'
);
$like_value="%$acronym%";
$stmt->bind_param("s", $like_value) or die("bind_param");
$stmt->execute() or die("execute");
$stmt->store_result();
echo "<p>num_rows: " .$stmt->num_rows .PHP_EOL;

Now, if what's inside the input box is "H&C" without qutes, no record is retrieved, Even though "US" gives me one record as expected.