Covid-19 vaccination alone will not able to prevent infection: Study

Coronavirus vaccinations to all adults in the United Kingdom are unlikely to completely stop the deadly virus, a new modelling study claimed. 

The study published in The Lancet Infectious Diseases Journal was done before the real-world data on vaccination rollout was available.   

The authors studied a range of levels of protection against infection. 

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They found that their model neither includes new coronavirus variants nor for the effects of waning immunity. 

This study modelled the combined interaction of the UK vaccination rollout with various scenarios of relaxing control measures, to predict the R-number and deaths and hospitalisations due to Covid-19 from January 2021 to January 2024.

It assumed vaccine uptake would be 95 per cent in the age group 80 and older, 85 per cent in 50–79, and 75 per cent in 18–49 group. 

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Vaccine protection against symptomatic infection was assumed to be 88 per cent based on phase 3 trial data from the Pfizer-BioNTech and Oxford-AstraZeneca vaccines, the two jabs administered in the UK. 

The vaccines' protection was varied in four scenarios: 0 per cent, 35 per cent, 60 per cent, 85 per cent.

The modelling suggests that though vaccination can substantially reduce R-number, it may not be enough to drive it below 1 without other preventive rules. 

Even in the best-case scenario which offers 85 per cent protection against Covid-19, the R number is estimated to be 1.58 without other measures. 

Since the vaccine alone cannot take R below 1, removing all restrictions after the vaccination is complete could lead to another wave of cases and a surge in the number of deaths, the study said.