Released today, Albert Bourla of Pfizer made a statement saying those who took the vaccine could possibly need another dose within a year of their previous vaccinations. He went on to say there is even a chance the vaccination would need to be done annually. Bourla, CEO of Pfizer, explained the annual need for the vaccination could be the biggest thing in order to fight against the virus.

In February, Johnson & Johnson made the announcement stating the same thing about the vaccine possibly needing to be taken annually. With it being so new, experts and researchers don't really know how long the vaccine will last after it has been administered.

Although some results have come back on the short-term effectiveness of the vaccine, all the companies know is that it can protect for at least six months. Pfizer released data stating their vaccine being administered is showing 95% effective up to six months after the second dose is taken. That data was based on 12,000 participants who were vaccinated at the time.

It is still hard to know how far out the vaccine will last, which is why a third or annual dose could be necessary in the future.

LOOK: Stunning vintage photos capture the beauty of America's national parks

Today these parks are located throughout the country in 25 states and the U.S. Virgin Islands. The land encompassing them was either purchased or donated, though much of it had been inhabited by native people for thousands of years before the founding of the United States. These areas are protected and revered as educational resources about the natural world, and as spaces for exploration.

Keep scrolling for 50 vintage photos that show the beauty of America's national parks.