Dr. John Molesworth, of Frederick Memorial Hospital, discusses the history of influenza in the U.S. during the First Tuesday Speaker Series at Christ Reformed United Church of Christ. Photo by Tabitha Johnston.

SHEPHERDSTOWN — One hundred years ago, the United States was in the middle of the most deadly two months in the nation’s history. The cause? The H1N1 influenza virus.

The Spanish influenza pandemic spread across the North American continent, killing about 675,000 American citizens and 20-50 million people worldwide — more than the combined totals of military deaths in World War I and World War II. Although the pandemic happened in a time when the disease may have been easily spread because of World War I soldiers’ unsanitary living conditions, according to Dr. John Molesworth, the pandemic’s centennial anniversary should raise awareness of the devastation influenza can cause.

“We have a false sense of security. With more worldwide travel happening today, disease is more likely to spread,” Molesworth said, mentioning Americans’ travel to second- or third-world countries increases the likelihood of uncommon strains of the flu virus being brought back to the United States.

Since most Americans have not been surrounded by these strains of the virus, they will not have built up immunity to them, which could lead to another pandemic in the future. Whether or not a pandemic will happen any given year is difficult for experts to predict, but according to Molesworth, the best way to avoid catching the flu is through getting a yearly vaccination at the beginning of fall.

“Flu is a virus that peaks in November and continues through May,” Molesworth said, during Christ Reformed United Church of Christ’s First Tuesday Speaker Series on Nov. 6. “The key thing is, just to get a vaccination for everyone. Remember the flu shot doesnt start working until two weeks after injection.”

According to Molesworth, flu immunizations are usually only effective for one year, and are made to target specific strains of the flu, based on the prevalent strains from the previous year’s flu season. Although people with an egg allergy may have reacted to the flu vaccine when it was first developed by using chicken eggs as virus incubators, the vaccine is now developed in a different way, so anyone can get the vaccination.

Molesworth said most people who contract the flu do not need to visit the hospital. But they should go to the hospital immediately if their symptoms become acute, including shortness of breath, uncontrolled cough or a recurring virus.

“Probably the most difficult cases I’ve seen in the emergency room at Frederick Memorial Hospital were of people who have come in too late with the flu,” Molesorth said. “The ones I’ve seen gone bad are very sad, and can often only be given comfort care.”

Two Walgreens employees were on hand at the event, offering flu immunizations to unvaccinated attendees.