All vaccines still seem to offer a significant degree of protection against serious illnesses caused by Omicron, which is the most crucial goal. But only the Pfizer and Modern injections, when reinforced by a booster, appear to have early success in stopping infections, and these vaccines are not available in most countries.

The other pictures – including those of AstraZeneca, Johnson & Johnson and vaccines made in China and Russia – do little or nothing to stop the spread of Omicron, early research shows. And because most countries have built their immunization programs around these vaccines, the gap could have a profound impact on the course of the pandemic.

A global wave of infections in a world where billions of people still go unvaccinated not only threaten the health of vulnerable people, but also increase the opportunity for the emergence of even more variants. The disparity in the ability of countries to overcome the pandemic will almost certainly worsen. And news about the vaccine’s limited efficacy against Omicron infection could reduce demand for vaccination in developing countries, where many people are already hesitant or concerned about other health concerns.