COVID-19 vaccine: A recent study revealed that people earlier infected with the SARS-CoV-2 virus still benefit from vaccination against COVID-19, gaining 60% to 94% protection against reinfection.
Data on vaccinations and infections from all Danish registrations were analysed for the study, which was published in the journal PLOS Medicine. The data included all Danes, who tested positive for the virus or got a vaccination between January 2020 and January 2022.
More than 200,000 people who tested positive for SARS-CoV-2 during each of the Alpha, Delta, and Omicron waves were examined by researchers at Statens Serum Institut in Denmark.
Vaccination provided protection against reinfection
According to their research, vaccination provided up to 71% protection against reinfection for those with prior illnesses during the Alpha period, 94 % protection during the Delta period, and 60% protection during the Omicron period, with protection lasting up to nine months.
“In our study, we find a significant vaccine effectiveness against SARS-CoV-2 reinfection, and this shows the importance of vaccination also for those who might be protected by natural immunity," said Katrine Finderup Nielsen from Statens Serum Institut.
These findings demonstrate that vaccination provided additional protection against SARS-CoV-2 during each of the three waves of the pandemic, beyond those provided by natural immunity.
Further studies needed to know more about vaccine's benefits: Researchers
However, researchers believed that the study was too brief to assess whether the vaccine offers protection against serious consequences including hospitalisation and death. They added that further studies with longer follow-up times will be necessary to answer this question.
"Even though vaccination seems to protect to a lesser degree against reinfection with the Omicron variant, these findings are of public health relevance as they show that previously infected individuals still benefit from COVID-19 vaccination in all three variant periods," they added.
From a public health perspective, these insights into vaccine effectiveness can help decision-makers plan the timing and execution of vaccination strategies to make them most effective, the researchers added.
(With inputs from PTI)
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