Global coronavirus cases surpassed 100 million on Jan. 27, according to a Reuters tally, as countries around the world struggle with new virus variants and vaccine shortfalls.

The new Covid-19 variant identified in South Africa can evade the antibodies that attack it in treatments using blood plasma from previously recovered patients, and may reduce the efficacy of the current line of vaccines, according to scientists.

Previous infection with the coronavirus may offer less protection against the new variant first identified in South Africa, although scientists hope that vaccines will still work.