AstraZeneca says late-stage studies of its COVID-19 vaccine have been “highly effective” in preventing disease

The study looked at two different dosage regimens. A half dose of the vaccine followed by a full dose at least one month apart was 90% effective. A second regimen using two full doses one month apart was 62% effective. The combined results showed an average efficacy rate of 70%.

“These results show that we have an effective vaccine that will save many lives,” Prof. Andrew Pollard, lead investigator of the trial. “Interestingly, one of our dosage regimens can be around 90% effective.”

AstraZeneca is the third major pharmaceutical company to report late-stage findings for its potential COVID-19 vaccine as public health officials around the world look forward to the vaccines that will end the pandemic that killed nearly 1.4 million of people. Pfizer / BioNTech and Moderna last week reported preliminary results from late-stage studies showing their vaccines were nearly 95% effective.

While the AstraZeneca vaccine can be stored between 2 C and 8 C, Pfizer and Moderna products must be stored at freezing temperatures. In Pfizer’s case, it needs to be kept at the ultra-cold temperature of around -70 C.

The AstraZeneca vaccine is also cheaper.

The findings come as COVID-19 infection rates are rising in most U.S. states and many countries, including Canada, amid a resurgence of the virus, which is once again prompting governments to close activities and limiting social gatherings around the world. England is still in the midst of a four-week lockdown that has closed all non-essential stores, while in the US, the government’s leading health agency has advised Americans not to travel to visit family and friends over the holidays. Thanksgiving this week.

AstraZeneca said it will immediately require early approval of the vaccine where possible, and will seek a list of emergency uses from the World Health Organization so it can make the vaccine available in low-income countries.

The vaccine uses a weakened version of a common cold virus that is combined with genetic material for the virus’s characteristic spike protein that causes COVID-19. After vaccination, the spike protein prepares the immune system to attack the virus if it subsequently infects the body.

A lower dose can reduce costs

Peter Openshaw, a professor of experimental medicine at Imperial College London, said the finding that a smaller starting dose is more effective than a larger one is good news because it can reduce costs and mean more people can be vaccinated.

“The report that an initial half dose is better than a full dose seems counterintuitive to those of us who think of vaccines as normal drugs. With drugs, we expect higher doses to have greater effects and more side effects,” he said. . “But the immune system doesn’t work that way.”

WATCH | Who would get a COVID-19 vaccine first and when?

With several COVID-19 vaccines being developed around the world, cost and effectiveness matter. However, according to epidemiologist Dr. Christopher Labos, logistical considerations may be the deciding factor in what becomes available across Canada. 5:41

Dr Christopher Labos, a Montreal-based cardiologist trained in epidemiology, said vaccines don’t have to be perfect or prevent every case of COVID-19.

“The point is to drastically reduce the workload, drastically reduce the number of new infections so we don’t have these outbreaks, so we don’t have hospital systems overwhelmed,” Labos told CBC News Network on Monday.

“This is the main take-home message from many of these vaccines. Not only do they prevent cases, but they appear to prevent severe cases of COVID-19.”

Labos said he suspected that since Pfizer / BioNTech and Moderna vaccines need to be stored at low temperatures, they will likely be restricted to institutions, while the Oxford / AstraZeneca vaccine could be rolled out in the community.

Dr Anand Kumar, an infectious disease expert and doctor of the intensive care unit in Winnipeg, said AstraZeneca used proven vaccination technology.

“We have months where we could still have horrendous death rates,” Kumar said. “That’s good news, but it’s along the way and we really need to get the virus under control.”

The findings reported on Monday come from studies in the UK and Brazil involving 23,000 people. Late stage trials are also underway in the United States, Japan, Russia, South Africa, Kenya and Latin America, with further trials planned for other European and Asian countries.

AstraZeneca has reported two pauses in the Phase 3 clinical trial of its vaccine candidate, AZD1222. “No serious safety events related to the vaccine have been confirmed,” the company said in a statement.

AstraZeneca has increased production capacity, so it can supply hundreds of millions of doses of the vaccine starting in January, CEO Pascal Soriot said earlier this month.

Soriot said on Monday that Oxford’s simpler supply chain of the vaccine and AstraZeneca’s commitment to provide it on a non-profit basis during the pandemic mean it will be accessible and available to people around the world.

“The efficacy and safety of this vaccine confirm that it will be highly effective against COVID-19 and will have an immediate impact on this health emergency,” Soriot said.

Now that AstraZeneca has released its interim results, regulators must approve the vaccine before it can be widely distributed.

Britain has ordered 100 million doses of the Oxford vaccine, and the government says several million doses can be produced before the end of the year if it gets regulatory approval. Canada has ordered 20 million doses, enough for 10 million people.

British Health Secretary Matt Hancock said he felt “a great sense of relief” at the news of the AstraZeneca vaccine’s effectiveness.

He said a few months ago, as the virus raged, “the idea that by November we would have three vaccines, all of which are highly effective, I would have teeth for eyes.”