How long will the Covid-19 vaccine protect you?

Trio of local experts weigh in

11 May 2021 - 12:44
Confusion abounds about the length of protection the vaccines provide against the coronavirus.
Confusion abounds about the length of protection the vaccines provide against the coronavirus.
Image: 123RF/Chayatorn Laorattanavech

Many people have pinned their hopes on the idea that life will return to “normal” once Covid-19 vaccines have been rolled out across the globe. However, there’s still much uncertainty about how long the protection from these vaccines (single and double dose) will last.

Rumours abound online, with some people saying you would need to have the jab every six months, or yearly like the flu vaccine. Others say one dose should be sufficient for life.

To clear the confusion, we asked three local experts this question: If I get inoculated, how long will a Covid-19 vaccine last?

Here’s what they had to say:

PROF PENNY MOORE

Moore is the SA research chair of virus-host dynamics at Wits University and the National Institute for Communicable Diseases.

At this stage we don’t know how long protection after vaccination will last for the simple reason that people have only recently received the vaccines. The data we do have indicates people are likely to retain some protection for at least six months, and perhaps much longer.

However, this doesn’t take into account the variants of SARS-CoV-2 that have already and probably will continue to emerge, including B.1.351 [the variant identified in SA]. Many of these variants are less sensitive to the antibodies that vaccines trigger, which may reduce the duration and extent of infection.

One way to combat the changing variants would be to take the same approach we use for flu and update the vaccines annually. But at this stage, that is a hypothesis and not a certainty.

PROF SHABIR MADHI

Madhi is a professor of vaccinology, director of the Vaccines & Infectious Diseases Analytics Research Unit at Wits University and co-director of African Leadership in Vaccinology Expertise.

Investigation regarding the duration of protection induced by Covid-19 vaccines remains ongoing. Currently the best evidence indicates protection for at least six months, which does not mean it won’t be longer.

Currently the best evidence indicates Covid-19 vaccines will provide protection for at least six months, which does not mean it won’t be longer.
Prof Shabir Madhi

Based on natural infection by coronavirus, many anticipate protection for at least two to three years against mild infection, but possibly even longer against severe disease.

The need for revaccination will be established as studies provide an answer on duration or protection.

Also, mutations of the virus could lead to the possibility of the need for more frequent boosting/new vaccines if they become evasive to immunity induced by vaccination.

PROF VERONICA UECKERMANN

Ueckermann is head of the infectious diseases department of the University of Pretoria.

We cannot say for certain. What we know about natural immunity is that it lasts at least up to eight months and we hope the same will be true for vaccines.

Pfizer and Moderna’s data confirmed immunity at six months after their second dose. Of course we are quite early in the trajectory post-vaccinations, so time and further studies will tell. At UP we are also part of a long-term follow-up of immunity after natural infection and after vaccination, and this will provide useful answers.

It is most likely we will need an annual vaccine, like with influenza. The question at the moment is whether immunity will be sustained for a full year after vaccination. 


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