Pharmaceutical giants had their work cut out for them as coronavirus wreaked havoc, globally. But with the introduction of newer variants – the UK and South Africa -, the climb became arduous. Albeit the vaccines produced showed promising results against the COVID-19, they are not as effective against the new variants, especially the South Africa variant.

Johnson & Johnson’s single-dose COVID-19 vaccine has overall efficacy of 66%, but the shot does not protect as well against a variant first detected in South Africa.

Encouragingly, the vaccine was able to prevent 85% of severe COVID-19 cases across all geographical regions however — a key indicator lauded by experts.

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Its effectiveness against all forms of the disease — mild, moderate and severe — was as high as 72% in the United States, but fell to 57% in South Africa, where a more transmissible new variant is dominant. In Latin America, it was 66% effective.

“We’re proud to have reached this critical milestone and our commitment to address this global health crisis continues with urgency for everyone, everywhere,” the company’s CEO Alex Gorsky said.

While the J&J vaccine is not as protective, the comparisons are not quite like-for-like, because those trials reported results before newer, more transmissible mutations of the virus became dominant in some parts of the world.

These variants, such as B.1.135 in South Africa and P.1 in Brazil, elude some of the blocking action of antibodies triggered by vaccines made against the common strain of the coronavirus.

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But the J&J vaccine requires only one shot, and can be stored for up to three months at 36-46 Fahrenheit (2-8 degrees Celsius), giving it a logistical edge over the Pfizer and Moderna vaccines.

J&J says that if gets permission for emergency use authorisation in the US, it is on track to deliver 100 million doses by June-end.

The Phase 3 J&J trial was conducted in eight countries, involving 43,783 people, 34% of whom were over 60.

This broke down to 19,302 in the US, 17,905 in Latin America and 6,575 in South Africa.

The differences in its efficacy across these regions further emphasises the growing threat posed by new variants.

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Anthony Fauci, the US top infectious disease official, said it highlighted the need to step up the vaccination rate quickly before new variants establish themselves firmly in the US, and to quickly develop new vaccines directed at variants.

As far as Novavax is concerned, trial results showed data that it was 50% effective overall at preventing COVID-19 among people in South Africa.

“It’s a different pandemic now,” said Dr. Dan Barouch, who helped develop the J&J vaccine.

Barouch was quick to notify that the new variants are substantially resistant to vaccine-induced antibodies.