A nurse displays a vial of Covishield, the AstraZeneca Covid-19 vaccine. Picture: REUTERS/FRANCIS MASCARENHAS
A nurse displays a vial of Covishield, the AstraZeneca Covid-19 vaccine. Picture: REUTERS/FRANCIS MASCARENHAS

For the past few months, the nation has watched in dismay as one country after another began administering Covid-19 shots, while local infections and deaths surged with no apparent end in sight. But, ironically, the government’s foot-dragging may turn out to have saved it from a costly mistake.

On Sunday, news broke that the 1-million Oxford-AstraZeneca shots that had landed in SA less than a week earlier and were set to be rolled out to health workers within a matter of days may not be up to the task. Preliminary clinical data from a small SA trial showed AstraZeneca’s vaccine did not protect people from the new coronavirus variant, known as 501Y.V2 or B1351, that now dominates transmission in SA.

The study, which has yet to be peer-reviewed, found the AstraZeneca shot offered only 22% protection against mild to moderate infection. Worse still, because the trial used mainly young volunteers with a median age of 31, the study provided no clear insight as to whether the vaccine would safeguard recipients from severe illness or death and so help prevent hospitals from being overwhelmed.

The news sent the government scrambling to redesign its strategy and within hours it announced it would put a temporary hold on the rollout and switch to an alternative vaccine developed by Johnson & Johnson (J&J), which has clearly demonstrated protection against Covid-19 caused by the 501Y.V2 variant.

Preliminary data from a large phase 3 trial found J&J’s single-shot vaccine was 57% effective at preventing mild to moderate illness in SA recipients, and 85% effective in preventing severe disease. These are compelling numbers and, as the government is clearly moving apace to secure stocks, they offer hope about immunising health staff with a vaccine that will be seen to be working. The same is true of its plans to speed up access to the Pfizer-BioNTech vaccine.

This is important, for while scientists and policymakers may be comfortable with the idea of a vaccine that only offers enough protection to keep people out of hospital, that is not an easy message to convey to anxious health workers and a sceptical public. Vaccine hesitancy is a real issue in many communities, and if the first stage of the government’s ambitious vaccination drive had gone ahead with a product that saw recipients still falling ill with Covid-19, it could have done untold harm to public confidence.

There may well be a role for the AstraZeneca vaccine in SA and many other countries awash with new coronavirus variants, and it would be reckless to simply leave these potentially life-saving vaccines to gather dust on a shelf. But the government is right to wait for clear, scientific evidence that they provide significant benefit and to take time to craft a careful communication strategy should it decide to administer them. The price will simply be too high if it does not.

But there is another important lesson here, which the government clearly recognises: the population needs to be inoculated, and fast.

Scientists have so far identified three particularly worrying variants — 501Y.V2 detected in SA, B117 in the UK, and P1 in Brazil — and it is only a matter of time before more are detected as countries step up surveillance. Vaccine manufacturers are now racing to figure out how effective their candidates are against the new variants compared to the original “wild type” virus, and devise more efficacious products.

The only way to stop new variants is by stopping the spread of the virus, since without a host it has no opportunity to replicate and mutate.

There are two ways to do this: the tried and tested non-pharmaceutical interventions of social-distancing, wearing masks, and ensuring hand hygiene; and getting vaccines into arms as quickly as possible.

Thus the government is right to press ahead with its plans to start vaccinating health workers next week, and it is equally correct to be cautious about AstraZeneca’s shots until there is more evidence. For the last thing it needs is to administer millions of doses that don’t work, and have to start the job all over again.


Would you like to comment on this article or view other readers' comments?
Register (it’s quick and free) or sign in now.

Speech Bubbles

Please read our Comment Policy before commenting.