JUST IN: Four cases of coronavirus re-infection confirmed in Qatar
— The Spectator Index (@spectatorindex) September 29, 2020
Cases of coronavirus re-infection, which remains a worrying concern for health experts, had been reported before the Hong Kong case as well, but could not be confirmed due to lack of data.
Some COVID-19 patients continue to test positive for the novel coronavirus infection for several months after their recovery from symptoms. Coronavirus reinfection can only be confirmed if COVID-19 test results show that the genetic makeup of each virus is different to a certain extent, which cannot happen through in-vivo evolution.
India has reported a few COVID-19 reinfection cases too, the first one coming from a 27-year-old woman who had tested COVID-19 positive nearly 30 days after she was cured and discharged from the hospital. The first case of coronavirus reinfection in India was reported from Bengaluru.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.