Did you catch the Queen's cold?

Britain's Queen Elizabeth II in a car with Prince Philip, arrives to attend the morning church service at St Mary Magdalene Church in Sandringham, England, Sunday Jan. 8, 2017. The 90-year-old British monarch was applauded by well-wishers as she arrived by car at St. Mary Magdalene Church in eastern England. It was her first public appearance in several weeks. (Chris Radburn/PA via AP)

At 90, stoic Queen Elizabeth II has rarely taken a sick day in the 64 years and 11 months she has ruled Great Britain, but a particularly brutal cold this past holiday season has had her laid up for more than two weeks.

She was finally seen in public on Sunday — the first time since before Christmas — when she attended a church service near her country estate. Her husband, Prince Philip, 95, was also struck down with the virus, characterized by a hacking cough.

According to experts, the bug believed to be causing the illness is a so-called adenovirus, rarer than the more garden-variety rhinovirus. The complex adenovirus, which has 30 genes compared to the nine found in a rhinovirus, often brings symptoms akin to those of bronchitis, which can last for weeks.

It seems that, like the queen, New Yorkers are not immune to the infection. Dr. Sonali Bose, a pulmonologist at the Mount Sinai National Jewish Respiratory Institute, regularly treats such serious upper-respiratory conditions.

“It’s important to remember the characteristics of the host [that] make them especially vulnerable, such as being younger, older or having a disease like asthma,” she says.

A prolonged cough is a common complaint for sufferers, and it can last up to two months after the virus has left the body because of the damage caused to the respiratory tract.

“The virus might be gone, but the mucus that has accumulated stays and triggers the cough,” Bose says.

In winter, she recommends a combination of rest and indoor activity to get the secretions mobilized.

“Good nutrition is also key,” she adds. “There’s a lot to be said for the old prescription of chicken soup and staying out of the cold.”