Discussion
So, in these two patients as we did not perform sequencing of the virus
in each episode so we can’t prove that it’s a reinfection from another
strain of the virus. But both patients had IgG antibodies present when
they got second infection so ideally, they should not have got
reinfected. Immune suppression due to chemotherapy may have reactivated
the virus but there are no reports of the same in the literature. Same
infection may have persisted but we have no proof of that as in between
two episodes virus was negative by PCR. Ct values in first case at first
diagnosis were high >30 so was it a false positive? At the
time of second infection Ct values were low <20. But patient
had IgG antibodies against SARSCOV2 present when he had second infection
suggesting first infection was real infection. In second patient Ct
values are low in both infection episodes and also, he had IgG antibody
against SARSCOV2 at onset of second infection suggesting first infection
was real and second infection is also real and possibly because of
another strain. Most neutralizing antibodies target the spike protein
(4). Several mutations in the spike protein receptor binding domain and
N-terminal domain have been shown to confer reduced susceptibility to
neutralizing antibodies (5). Both our patients had IgG antibodies
against SARSCOV2 at the time of onset of second infection so only way
new infection could have happened is if they got infection from a new
strain of virus which could escape these antibodies.
Our two cases raise more questions then give answers. More data is
needed to confirm this phenomenon of reinfection in Covid19.
Disclosure – All authors have nothing to declare. All authors
have contributed to the manuscript.