A newly released paper said that the duration of "natural or vaccine-induced immunity" is yet to be completely understood, but it has estimated that a protective immune response after the novel Coronavirus infection or vaccination may last for 90 days.
The scientists stated that based on the variability in the data and differential responses in individuals, "we conservatively estimate that a protective immune response after SARS-CoV-2 infection or vaccination may last for 90 days."
Immunity Against Virus
This estimation is based on the fact that other viruses from the Coronavirus family tend to reinfect after one or two years. According to scientists, reinfections with seasonal Coronaviruses happen frequently at 12 months and sometimes as early as six-months.
They also explained that based on the accumulated information, it was concluded that "within one month of natural infection, a high proportion of people will develop immunity which is protective against disease caused by reinfection (high confidence)." According to the researchers, this protection is likely to persist for at least three months, while the level of protection against the "subclinical re-infection (as opposed to disease) is uncertain".
The scientists also added that 28 days after the first dose of an effective vaccine, a higher portion of the population develops immunity which is "protective against disease caused by reinfection (high confidence)." But there is a possibility that a small portion of the people may not develop immunity following either natural infection or vaccination (high confidence). "The proportion is unknown but it is likely to be small (moderate confidence)," said the scientists.
The newly released paper added that the novel Coronavirus antibodies can be detected in at least 90 percent of the people who have been infected with the virus and "with new assays this figure approaches 100 percent".
According to the findings published on Friday, December 4, antibodies can be measured within almost a week of symptoms developing. It also added that the trials of the vaccines to protect people from the new Coronavirus-caused disease suggested that "a high degree of immunity to COVID-19 disease can be obtained, at least in the short-term".
Despite some uncertainties about the levels, as well as the duration of immunity, scientists concluded that "some form of COVID-19 immunity certification is likely to be possible but further data and considerations are needed before a recommendation can be made".