Third vaccine checks in with promising trial results

London — AstraZeneca on Monday became the third pharmaceutical company to announce positive results from late- stage trials of a coronavirus vaccine, saying that its candidate, developed by Oxford University, was “highly effective.”

Scientists and politicians alike hailed the third straight week of buoyant scientific news as a sign that, even as coronavirus cases surge to devastating levels in many countries, an end to the pandemic is in sight.

The AstraZeneca trial was 70% effective overall, with up to 90% efficacy in a smaller group that got a lower dosage. Pfizer, BioNTech and Moderna have each reported vaccines that were 95% effective in clinical trials. Different trial designs make direct comparison complicated, but even with somewhat lower protection, the AstraZeneca vaccine may be a more realistic option for much of the world because it may be less expensive and does not need to be stored at subzero temperatures.

Peter Piot, director of the London School of Hygiene & Tropical Medicine, who was instrumental in the battle against AIDS, said the positive results from three vaccine candidates cannot be overestimated.

He said that “2020 will be remembered for the many lives lost from COVID-19, lockdowns and the U. S. election. Science should now be added to this list.” He added that “the only way to stop COVID-19 in its tracks is having multiple effective and safe vaccines that can be deployed all around the world and in vast quantities.”

“I’m totally delighted,” said Hildegund C.J. Ertl, a vaccine expert at the Wistar Institute in Philadelphia. “What it tells me is this virus can be beaten quite easily: 90 to 95% efficacy is something we’d dream about for influenza virus, and we’d never get it.”

In years when the flu vaccine is a good match for the strain in circulation, it ranges between 40 and 60% effective.

The Oxford-AstraZeneca team said in a video conference with journalists that its candidate offered 90% protection against the coronavirus when a subject received half a dose, followed with a full dose one month later. Efficacy was lower — 62% — when subjects received two full doses a month apart.

Andrew Pollard, chief investigator of the Oxford trial, said the findings showed that the vaccine would save many lives.

“Excitingly, we’ve found that one of our dosing regimens may be around 90% effective, and if this dosing regimen is used, more people could be vaccinated with planned vaccine supply,” he said.

Britain has preordered 100 million doses — which at a dose and a half per person would cover most of its population. The United States has ordered 300 million, though both countries have hedged their bets and signed multiple vaccine deals.