Effectiveness of vaccines

Source: This post is based on the article “Effectiveness of vaccines” published in The Hindu on 2nd September 2021.

What is the News?

According to a study, natural infection confers stronger immunity against the SARS-CoV-2 virus than even full vaccination. 


Natural Immunity following a virus infection lasts longer is already well known. For Example, People infected with the 2002 Severe Acute Respiratory Syndrome (SARS) and the Middle East Respiratory Syndrome(MERS) have been shown to have strong immunity for up to three years.

However, a study has now shown that natural infection confers stronger immunity against the SARS-CoV-2 virus also than even full vaccination.

About the Study

The study was undertaken in Israel, as it was the first country to vaccinate a large percentage of the population with the Pfizer vaccine.

The researchers compared over 16,000 people who were previously infected but not vaccinated with an equal number of people who had not been naturally infected but fully vaccinated.

What were the findings?

The researchers have found that people previously infected with the Covid-19 virus had better immunity, reduced risk of reinfection, than uninfected people who were fully immunised with the Pfizer vaccine.

What are the flaws in the study?

The study has not informed if the level and duration of immunity protection varies depending on the severity of the disease and whether asymptomatic infection confers the same protection as those with the disease.

What are the other findings of the study?

One encouraging finding of the study is the absence of death among the vaccinated. This is a clear signal that the vaccine offers formidable protection against serious infections. 

Hence, natural immunity, even if found to be superior and long-lasting than vaccine-induced protection, is not what one should opt for.

Vaccination will always remain a safe and sure way to remain protected against severe COVID-19 disease and death, even if it means the protection is not robust or long-lasting.

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