There was so much to look forward to at the start of 2021 .
The question was when , and not if , the health crisis that spread from a market in Wuhan , China would finally end .
Scientists developed two highly effective vaccines against the coronavirus in record time .
Several more were waiting for approval .
Governments in the United States , Europe , and Israel spent billions of dollars to start the biggest vaccination program in history .
China and Russia developed their own vaccines .
And the UN-backed COVAX program purchased shots for developing and poor countries around the world .
In May , the U.S . and Western nations expanded the program to vaccinate young children .
Health officials issued new guidelines advising that fully vaccinated people no longer needed to wear face coverings in most situations .
The move was seen as the first step toward returning to normal conditions that existed before the pandemic .
But , scientists began to worry about the new versions of the coronavirus , called variants , soon after people started to receive the new vaccines .
It is normal for viruses to mutate , or change , over time .
A mutation that strengthens the virus helps it to spread by pushing out the weaker versions .
In February , the head of Britain's vaccination effort said the world faced around 4,000 variants of the virus that causes COVID-19 .
But only some would raise concern .
The two most worrisome variants now are Delta and Omicron .
In the early days of the pandemic , many Asian countries appeared to have successfully fought the virus with strong measures .
By July , countries , including Japan , South Korea , Vietnam , and Thailand , were setting records for new cases and deaths .
The Delta variant appeared at a difficult time .
When it started being reported , vaccination rates remained low in many countries .
And officials were moving quickly to reopen economies .
Then , infections of the Delta variant became widespread .
Governments , businesses , and schools reacted with more vaccination requirements and restrictions .
Some countries started to restrict international travelers and closed borders over concerns about the fast-spreading Omicron variant .
After another year of face coverings , restrictions , vaccines and variants , people are beginning to wonder whether this pandemic will ever go away .
The answer is yes and no .
Many scientists believe that the new coronavirus is here to stay .
In February , the science publication Nature reported the results of a study involving more than 100 scientists .
Endemic means the virus will continue to exist in some areas for years to come .
For example , Malaria is considered endemic to many warm , wet areas across countries in Asia , Africa , and South America .
But it is not a problem in the United States or other Western nations .
The way to end a pandemic is to reach herd immunity .
Herd immunity is when many people in a community either have recovered from an infection or have been vaccinated .
It does not mean everyone is protected from the virus .
However , when herd immunity is reached , the virus can no longer spread easily , which helps protect those who are at risk .
As nations joined together to fight the pandemic , health officials started to sound the alarm about another public health crisis : mental health .
There is hope , however .
Although health officials have already approved several treatments for COVID-19 , all of them must be injected by healthcare workers .
But pills can be taken at home and are easier to send around the world .
And I'm Mario Ritter , Jr .