The new coronavirus infection (COVID-19) Omicron mutant virus has a higher risk of re-infection after being infected and recovering compared to the existing Corona 19 virus.
According to the industry on the 8th, Reuters, citing the results of a preliminary study published in South Africa (South Africa), reported that booster vaccination could provide protection against this mutation as well. The results of this study were recently published on medRxiv.org, an online pre-disclosure online site, before formal peer review.
◇The risk of re-infection is higher than the risk of first infection in November
The research team at Stellenbosch University and Wittwatersland University in South Africa, who published the results of this study, examined whether 2,796982 people who were confirmed with Corona 19 in South Africa from March 2020 to November 27, 2021 were reinfected. analyzed.
The research team selected 35,670 patients who tested positive again after 90 days from among the patients who tested positive, and found that the reinfection rate was 1.3%.
As a result of the analysis, 332 of the reinfected people tested positive for COVID-19 three times, and one person tested positive for COVID-19 four times. Of the 332 people infected with COVID-19 three times, 47 (14.2%) were found to have been infected in November 2021.
During the epidemic period that occurred before November 2021, the risk ratio of reinfection was 0.71 to 0.75. This means that the risk of reinfection is smaller when comparing the risk of first infection as 1.
On the other hand, the risk ratio of reinfection after November 2021 was 2.39, increasing the relative chance of reinfection during that period. This means that patients who have had COVID-19 are more than twice as likely to be infected with COVID-19 again than the probability of being infected with COVID-19 for the first time.
In order to finally confirm the mutation that caused reinfection, the gene sequence of the virus must be analyzed. The research team also explained that it is not yet possible to accurately prove whether reinfection caused by omicron mutations.
The research team explained, “Nevertheless, the increase in the number of presumed cases of reinfection with COVID-19, which surged last month, strongly suggests the possibility that the number of cases of infection caused by the appearance of omicron mutations is the cause.”
◇ Domestic reinfection rate 0.032%… Omicron mutation is not reflected yet
Meanwhile, as of November 26, the reinfection rate of COVID-19 in Korea was 32 per 100,000. In the case of the Omicron mutation, which is feared for a recent epidemic, it is still unknown whether or not it is re-infected in Korea as the epidemiological investigation is still in the early stage and the number of confirmed cases is only in the 30s.
Park Young-joon, head of the epidemiological investigation team at the Central Quarantine Countermeasures Headquarters (Bangdaebon) said, “So far, 138 presumed reinfection cases have been registered and managed.
Of the 138 cases, 20 cases were confirmed as reinfection through laboratory analysis.
◇In the Israeli study, the positive rate of booster immunizations was 1.8% vs. second immunizations 6.6%
A study recently reported in Israel suggests that at least the current booster dose of the COVID-19 vaccine provides strong protection in the short term.
According to a study published in the Journal of Internal Medicine of the American Medical Association (JAMA Internal Medicine) by an Israeli health care organization research team on November 30, those who received the second dose of the vaccine were more likely to test positive for COVID-19 than those who received the booster dose. more than three times the positive test rate of
The research team conducted a gene amplification (PCR) test on 306,000 adults vaccinated with Pfizer. About half of those who received the PCR test consisted of boosters, and the other half were those who had had their second dose for at least five months.
As a result of the test, 1.8% of the group who received the booster vaccine tested positive for COVID-19, while 6.6% of the people who had only received the second vaccine tested positive.
The researchers estimated that people were 86% less likely to test positive for COVID-19 between 4 and 9 weeks after receiving the booster dose.
According to local media on the 5th, the COVID-19 advisory committee of the Israeli Ministry of Health will discuss the fourth vaccination for the immunocompromised within this week.