One of the first confirmed cases of reinfection with the South African coronavirus variant has been reported in France in a study published on Wednesday in the Clinical Infectious Diseases journal.
The subject of the case was a 58-year-old patient with a history of asthma who was found to have been infected with the South African variant four months after recovering from a first episode of COVID-19, according to the study.
In September of last year, the patient was diagnosed with COVID after experiencing mild fever and shortness of breath and receiving a positive PCR swab test. He recovered within a few days and tested negative twice in December.
In January, about four months after initially testing positive, the patient entered the hospital with recurrent shortness of breath and fever and tested positive for the novel coronavirus again. Genome sequencing found that he was now infected with the South African variant. About a week after arriving at the hospital, the patient developed severe acute respiratory distress syndrome and was intubated and put on a ventilator.
Antibody testing found immunoglobin antibodies against SARS-CoV-2, the novel coronavirus. The patient had no evidence of any immunological disorder and was still in critical condition when the study was submitted to the journal.
The study stressed that the first infection happened a month before the South African strain emerged, ruling out the hypothesis that the reinfection was just persistent viral shedding.
Prior studies have suggested that those who recover from the virus generally have immunity against reinfection for at least six months. However, there have been reports of cases of reinfections even in people who have antibodies against the virus, with some cases being more severe with the reinfection.
The study published last week stressed that further investigation is "urgently needed" to assess cross immunity between the different variants of the virus and to monitor vaccine effectiveness against new variants. Initial studies have found that treatments using blood plasma from recovered patients were less effective against the South African variant and scientists have expressed concerns that the variant may be resistant to currently available vaccines, although the vaccine is still considered to be acceptably effective even against the various variants currently circulating.
In late January, an Israeli who was infected with the novel coronavirus in August was found to be reinfected with the South African variant, according to Ynet. However, in the Israeli case, the patient did not show any significant symptoms and did not infect anyone else in his household with the second infection, despite experiencing more difficult symptoms with the first infection. Prof. Shai Efrati, director of the Sagol Center for Hyperbaric Medicine and Research at the Yitzhak Shamir Medical Center, who studied the Israeli case, believes that the antibodies from the first infection protected the patient from developing a serious case or infecting others with the second infection, despite not protecting them from carrying the virus.