Worries mount over Russia's rushed Covid-19 vaccine

When Vladimir Putin announced Tuesday that Russia had approved a coronavirus vaccine — with no evidence from large-scale clinical trials — vaccine experts were worried.“I think it’s really scary. It’s really risky,” said Daniel Salmon, the director of the Institute for Vaccine Safety at Johns Hopkins University.Salmon and other experts said that Russia is taking a dangerous step by jumping ahead of so-called Phase 3 trials. 

Unlike experimental drugs given to the sick, vaccines are intended to be given to masses of healthy people. So they must clear a high bar of safety standards. Credit: iStock

If hundreds of millions of people get a vaccine, even a rare side effect could crop up in thousands of people. Over the course of the past century, researchers have developed increasingly powerful ways to test vaccines for safety and effectiveness. Some of those lessons were learned the hard way, when a new vaccine caused some harm. But vaccines are now among the safest medical products in the world, thanks to the intense rigor of the clinical trials tracking their safety and effectiveness. Credit: Reuters

This testing typically begins before a single person has received a new vaccine, when researchers inject it into mice or monkeys to see how they respond. If those animal studies turn out well, researchers then enlist a few dozen volunteers for a Phase 1 trial, in which all volunteers get the experimental vaccine. Credit: iStock

If Phase 1 trials do not turn up serious safety problems, then researchers usually move to a Phase 2 trial, in which they inject hundreds of people and make more detailed observations. Credit: iStock

The first clinical trials on coronavirus vaccines started in March, and now there are 29 underway, with more to launch soon. Companies such as AstraZeneca, Moderna, Novavax and Pfizer are beginning to share optimistic early results: So far, they have only detected mild or moderate symptoms and no severe side effects. Volunteers have also produced antibodies to the coronavirus, in some cases more than are produced by people who have recovered from an infection. But no matter how promising these early results, Phase 3 trials can fail. Credit: AFP

The timing of Russia’s announcement makes it “very unlikely that they have sufficient data about the efficacy of the product,” said Natalie Dean, a biostatistician and infectious disease expert at the University of Florida who has warned against rushing the vaccine-approval process. Credit: iStock

Even vaccines that have produced promising data from early trials in humans have flopped at later stages. The Russian researchers have not yet begun that crucial test. Credit: AFP

In June, the Gamaleya Research Institute of Epidemiology and Microbiology at the Health Ministry of the Russian Federation registered a combined Phase 1 and 2 trial on a vaccine called Gam-COVID-Vac Lyo. The researchers planned to test it on 38 volunteers. They said that the vaccine was made from an adenovirus — a harmless cold virus — carrying a coronavirus gene, similar to what AstraZeneca and Johnson & Johnson are using in their vaccines. The technology is still relatively new: The first adenovirus vaccine for any disease was approved for Ebola in June.Credit: AP

Since then, Russian officials have claimed that they would be moving the vaccine quickly into manufacturing. Putin’s announcement Tuesday made it official. Yet the institute has never published its Phase 1 and 2 trial data. Credit: Reuters

Along with determining whether the vaccine protects people, Phase 3 trials can reveal uncommon side effects that may not have shown up in the comparatively small number of volunteers who enrolled in the earlier phases. By comparing large groups of people who received the vaccine versus the placebo, researchers can identify unusual clusters of cases in the vaccinated participants. Credit: AP

Along the way, vaccine developers share these results in reports to government regulators and in peer-reviewed papers for scientific journals. Outside experts then evaluate the data from Phase 3 trials and give their recommendation to the FDA, which then decides whether to approve a vaccine for widespread use. Credit: Reuters

And even after a vaccine is licensed, researchers still keep an eye on it to make sure it’s safe. As millions of people get a vaccine, even rarer side effects may emerge over time. It’s also possible that certain groups of people, such as children or the elderly, turn out to face risks from a vaccine that weren’t immediately clear from the Phase 3 trials. Credit: Reuters