In a “good news story” for the world, health officials are tentatively welcoming research that shows only one dose of the Oxford vaccine could offer sustained protection against COVID-19.
New analysis of the trials showed just one dose of the Oxford/AstraZeneca vaccine was 76 per cent effective in preventing symptomatic illness for up to 90 days, and reduced transmission of the disease by 67 per cent.
The Oxford vaccine, along with other coronavirus vaccines in development, are designed to be administered in two doses, 21 days apart.
Faced with an overwhelming emergency situation, the UK government in December decided to only give its citizens the first dose, as a stop-gap measure.
They pushed the second jab out to 12 weeks. After the second dose, the efficacy of the vaccine is bumped up to 82.4 per cent, the research showed.
The preliminary findings are under review by The Lancet, but appear to support the UK government’s bold decision.
“On the face of it, it’s pretty encouraging,” Professor Brendan Crabb said, director and CEO of the Burnet Institute in Melbourne.
“There are no cases of severe disease, no hospitalisations.”
UK health officials hoped the extended period would help drive down hospital admissions. And it looks like the gamble has paid off, Professor Crabb said.
“This evidence is saying that it looks OK,” he told The New Daily.
Professor Crabb said this was also good news for Australia, as the Oxford vaccine is being manufactured here.
That doesn’t mean we will follow the same route as the UK – that decision will ultimately be left to the TGA.
“One shot looks effective in the UK circumstance. It’s out of desperation they have gone done this route,” Professor Crabb said.
“I think its way too early to say it would be recommended here, let’s let the situation play out.”
The concern though, is that the single-dose could speed up mutations of the virus, Professor Crabb said.
“In an environment where you have a lot of virus circulation, some escape that immunity. That’s a theoretical problem [the UK is] wrestling with,” he said.
For now, administering one shot of the vaccine will hopefully save thousands of lives and ease the burden on UK hospitals.
New mutations create concern
But with hope comes alarm, as another mutation of COVID-19 in the UK raises concerns it could impact the effectiveness of vaccines.
Governments and scientists are increasingly concerned about the mutation “Eeek”, which has already been seen in variants in South Africa, Brazil, and in the last few days in the US.
The mutation appears to be somewhat resistant to the vaccines, and more likely to cause reinfection among people who were previously infected.
According to a report by Public Health England, the mutation has been found in at least 11 samples of the UK’s B.1.1.7 strain and researchers believe some of the samples acquired the mutation independently, rather than it being spread from another case.
Professor Crabb said it was not surprising new mutations were developing, but said vaccines should still be somewhat effective.
“We have an idea the vaccines will still work, but you wouldn’t expect them to work as well against some variants,” he said.
The faster COVID-19 spreads through a community, the more likely it is to mutate.
This is why it is important to vaccinate as many people globally as possible and to implement strict public health measures, like Australia has done, to get the case rates down, Professor Crabb said.
“The less virus there is, the slower it is to mutate,” he said.
“In letting it get out of control you don’t just see a huge amount of death and suffering, but you create conditions that are ripe for the emergence of worse variants.”