New data show that the South African toll virus variant is taking effect on the vaccine

CHICAGO (Reuters) – Data from clinical trials on two COVID-19 vaccines show that a variant of the coronavirus first identified in South Africa decreases its ability to protect against the disease, and underscores the need to vaccinate large numbers of people as quickly as possible, according to scientists. .

Novavax Inc and Johnson & Johnson vaccines were received as important future weapons to curb deaths and hospitalizations in a pandemic that has infected more than 101 million people and caused more than 2 million lives worldwide .

But they were significantly less effective in preventing COVID-19 in participants in the trials in South Africa, where the new potent variant is widespread, compared to countries where this mutation is still rare, according to preliminary published data for companies.

“It is clear that mutants have a diminishing effect on vaccine efficacy,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in a briefing. “We can see that they will challenge us.”

Novavax on Thursday reported the results of mid-stage trials that showed its vaccine was 50% effective in preventing COVID-19 among people in South Africa.

This compared to the results of the UK final phase, in which the vaccine was effective up to 89.3% in the prevention of COVID-19.

On Friday, J&J said a single shot of the coronavirus vaccine was 66% effective in a massive trial on three continents.

But there were big differences by regions. In the United States, where the South African variant was first reported this week, the effectiveness reached 72%, compared to only 57% in South Africa, where the new variant, known as B 1,351 , accounted for 95% of COVID-19 cases reported at trial.

Another highly transmissible variant first discovered in the UK and now in more than half of US states has been less able to evade vaccine efficacy than its South African counterpart.

The new findings, however, raise questions about how Pfizer Inc.’s highly effective vaccines with partner BioNTech and Moderna Inc. will have an advantage over new variants. Both vaccines showed about 95% efficacy in trials conducted primarily in the United States before new versions of the virus were identified in other countries.

“It’s a different pandemic now,” said Dr. Dan Barouch, a researcher at Beth Israel Deaconess Medical Center at Harvard University School of Medicine in Boston, who helped develop the J&J vaccine.

Barouch said there is now a wide variety of new variants circulating, including in Brazil, South Africa and even the United States, that are substantially resistant to vaccine-induced antibodies.

Pfizer chief executive Albert Bourla said there was “a high chance” that emerging variants would end up making the company’s vaccine ineffective.

“That’s not the case yet … but I think it’s very likely that one day this will happen,” Bourla told the World Economic Forum. The pharmacist is studying whether to modify his vaccine to defend himself against the South African variant.

“LET HOSPITALS DO NOT GO INTO CRISIS”

Experts said the four vaccines still have great value in their ability to reduce severe COVID-19.

“The final game is to stop death, prevent hospitals from going into crisis, and all these vaccines, even against the South African variant, seem to do so substantially,” said Dr. Amesh Adalja, an infectious disease expert. of the Johns Hopkins Center for Health Security

For example, the J&J vaccine was 89% effective in preventing serious disease in South Africa.

J&J Scientific Director Dr. Paul Stoffels said he suspects that a type of immune system reaction called a T-cell response is playing a protective role and may help prevent serious illness.

“We knew it to some extent, but it’s also better and very confirmatory that we can see it now in the clinic,” Stoffels said in an interview.

Nevertheless, Fauci said the decline in efficacy rates underscores the need to closely monitor variants and accelerate vaccination efforts before even more dangerous mutations appear.

“The best way to prevent a new evolution of a virus is to prevent it from spreading,” Fauci said, “and do it by vaccinating people as quickly as possible.”