Hybrid Immunity Protects Better Against Hospitalisation and Severe COVID Infection
hybrid immunity
Those with hybrid immunity enjoy better protection from hospitalisation and severe COVID even after a year.

Hybrid immunity from a combination of being vaccinated and previously infected with COVID-19 offers better protection against hospitalisation and severe infection than immunity simply from a previous infection, according to a new study in The Lancet.

People with hybrid immunity were 97.4% less likely to be hospitalised or suffer severe infection at 12 months, whereas those who were previously infected but unvaccinated were 74.6% less likely, according to the study, which was funded by the World Health Organization (WHO) and the Coalition for Epidemic Preparedness Innovations (CEPI).

The likelihood reported on unvaccinated individuals could, however, be a combination of several factors, while “exposure could also differ between groups, as in the case of individuals who are unvaccinated because they are severely immunocompromised, and thus also have a greater risk of infection”.

The study analysed 26 papers, of which 11 reported on the immunity derived from previous infections and 15 reported on hybrid immunity. 

Individuals with immunity from previous infections were 25% less likely to be reinfected at 12 months, while individuals with hybrid immunity were 42% less likely to be reinfected at 12 months.

Individuals who had previously been infected and received their first booster doses were 95% less likely to be hospitalised or severely ill and 47% less likely to be reinfected six months after receiving the booster. 

“Individuals with hybrid immunity had the highest magnitude and durability of protection, and as a result might be able to extend the period before booster vaccinations are needed compared to individuals who have never been infected,” the authors noted.

They added that individuals with previous infection and full primary vaccination can delay receiving their booster shots by six months, while still having high protection against severe COVID. 

The analysis demonstrates the advantages of vaccination even after people have had COVID-19, the WHO said in a press statement. 

In countries with low resources and high infection rates, this evidence can come in handy for policy-makers. 

“In settings with high seroprevalence, scarce resources, and competing health priorities, evidence suggests that it is reasonable to focus on achieving high coverage rates with primary series vaccination among individuals who are at higher risk of poor outcomes, as this will provide a high level of protection against severe disease for at least 1 year among those with previous infection,” the authors added. 

Image Credits: Photo by Mufid Majnun on Unsplash.

Combat the infodemic in health information and support health policy reporting from the global South. Our growing network of journalists in Africa, Asia, Geneva and New York connect the dots between regional realities and the big global debates, with evidence-based, open access news and analysis. To make a personal or organisational contribution click here on PayPal.