While many in the public and in the media may believe a SARS-CoV-2 vaccine will be a one-and-done immunization, the reality may be much closer to a seasonal vaccine, according to Anthony Fauci, MD, director of the National Institutes of Allergy and Infectious Diseases.

For our comprehensive coverage and latest updates on COVID-19 click here.

“When you look at the history of coronaviruses, the common coronaviruses that cause the common cold, the reports in the literature are that the durability of immunity that’s protective ranges from 3 to 6 months to almost always less than a year,” he said in an interview with Howard Bauchner, MD, editor of JAMA. “That’s not a lot of durability and protection.”

Dr. Fauci also stated that a biotech company expects to enroll approximately 30,000 individuals in July for a phase 3 trial of their leading vaccine candidate. At least four other trials of potential vaccines are also underway.

While solid data and appropriate conclusions may take months, scientists and officials are hopeful that a successful vaccine will be ready in the first half of 2021—a record-breaking time frame from identification of a pathogen to release of a safe and effective vaccine.

The evaluations of potential vaccine candidates are underway even as researchers do not fully understand how the immune system responds to infection.

In congressional testimony last month, Dr. Fauci expressed cautious optimism that a viable vaccine candidate will emerge.

“You can have everything you think that’s in place and you don’t induce the kind of immune response that turns out to be protective and durably protective,” he said. “So one of the big unknowns is, will it be effective? Given the way the body responds to viruses of this type, I’m cautiously optimistic that we will with one of the candidates get an efficacy signal.”

Mass production will begin early

Mass production of the vaccines will likely begin before FDA approval, and even before complete trial data are ready.

“We’re going to start manufacturing doses of the vaccines way before we even know that the vaccine works,” Dr. Fauci said. “We may know whether it’s efficacious or not by maybe November, December. Which means that by that time, we hopefully would have close to 100 million doses. And by the beginning of 2021, we hope to have a couple of hundred million doses.”

He added that there is never a guarantee that an effective vaccine is possible, but early studies have offered hope.

“If the body is capable of making an immune response to clear the virus in natural infection, that’s a pretty good proof of concept to say that you’re going to make an immune response in response to a vaccine,” he explained.

However, researchers are still unclear whether patients who have been naturally infected develop a robust immunity, and for how long that immunity may last.

This story is contributed by Paul Basilio and is a part of our Global Content Initiative, where we feature selected stories from our Global network which we believe would be most useful and informative to our doctor members.