The protection from any potential COVID-19 vaccine is likely to be short-lived and may need to be stepped up to extend protection, White House health adviser Anthony Fauci said at 6 p.m. Edt.
As several companies move closer to the end line of potential coVID-19 vaccine development, the role of antibodies becomes more important because it will determine the effectiveness of the vaccine and how long an individual needs to be vaccinated or strengthened to extend protection.
Asked how long antibodies protect against infection, Fauci replied, “We don’t know.”
“We assume it has some level of protection, but we have to assume that the protection is limited,” he said during a question-and-answer session with NIH Director Francis Collins.
It won’t be like the measles vaccine.”
The measles, mumps and rubella vaccines are known to provide lifelong immunity.
Any potential coVID-19 vaccine is unlikely to have the same effect, Fauci said.
“So, we will continue to study these cases, and we may need to strengthen protective measures,” he said. “We don’t know yet how long it will last.”
Reports of coVID-19 patients recovering from re-infection may be inaccurate.
Fauci said a test to test for viruses from novel Coronavirus would most likely have extracted a fragment of the virus from a patient who is still recovering but may not have been reinfected.
In the sense of viral replication, there is no evidence that a patient has a relapse after improving.
I wouldn’t be surprised if there were rare cases of remission followed by a relapse, but I believe it’s not a widespread phenomenon.”
He added that other viruses, including Ebola, have shown the ability to re-infect people who have recovered.
“When you look at the history of coronaviruses, the coronaviruses that cause the common cold, the literature shows that the protective immunity lasts from three months to six months, almost always less than a year,” he said last month.
It’s not very durable protection.”
Fauci has previously said that coVID-19 vaccines may not provide long-term immunity.
Fauci said Monday that officials will likely know by early 2021 whether vaccine candidates currently under development are safe and effective.
Astrazeneca and Moderna are currently the two companies that have gone furthest in developing vaccine candidates.
“Our hope is that by the end of this year or early 2021, we will at least know whether these or more vaccines are safe and effective,” Fauci said.
Moderna expects to have its vaccine candidate in phase iii clinical trials by the end of this month, though STAT News reported last week that Moderna has delayed the trial date.
The phase III trial will be the most comprehensive test of a candidate vaccine, involving about 30,000 trial participants.
If all goes well and proves safe and effective for humans, the vaccine could be distributed before the end of the year.