I have been vaccinated, how likely am I to be reinfected with Covid-19?

Unvaccinated people who previously had Covid-19 are more than twice as likely to be reinfected than people who were fully vaccinated after contracting the virus. 

This is according to a recent study done by the US Centers for Disease Control and Prevention (CDC). 

The study assessed data on reinfections during May and June 2021 among hundreds of people who tested positive for Covid-19.

It found that people with previous infections through June had 2.34 times the odds of reinfection compared with those who were fully vaccinated. 

The CDC said the findings suggest that among people who have had Covid-19 previously, getting fully vaccinated provides additional protection against reinfection.

“If you have had Covid-19 before, please still get vaccinated,” said CDC director Dr Rochelle Walensky. 

“This study shows you are twice as likely to get infected again if you are unvaccinated. Getting the vaccine is the best way to protect yourself and others around you, especially as the more contagious Delta variant spread.”

AM I PROTECTED AS SOON AS I GET THE JAB?

The National Institute for Communicable Diseases (NICD) said it typically takes two weeks after vaccination for the body to build immunity against Covid-19.

The NICD said good data is emerging showing that breakthrough asymptomatic infections — Covid-19 infections after vaccination — are uncommon within 10 days after one dose  and extremely uncommon after two doses of Pfizer or Moderna vaccines.

“The infections after vaccination are usually mild and do not require hospitalisation,” said the NICD.

HOW WILL I KNOW REINFECTION HAS NOT OCCURED?

The NICD suggests that over time, collecting serial respiratory samples to isolate live viruses in tissue culture from multiple persons testing positive by RT-PCR (reverse transcription polymerase chain reaction) following recovery is needed. 

“If repeated attempts to recover live viruses in culture are unsuccessful, that would be sufficient evidence that infectious virus is absent. 

“Then we would be sure that people continuing to test positive do not pose a risk of infecting others. The added approach is to show the initial infecting virus and second infecting virus are sufficiently different,” said the institute. 

The NICD said there are no standardised methods to confirm reinfection.

“Confirmed reinfection appears to be a rare event. With  declines in the numbers of Covid-19 cases, time and resources will become available to focus on such cases,” said the  NICD.