Covid vaccines: Top candidate 90% effective, latest on Russia's Sputnik V, and trial starts in SA

(Photo: Pixabay)
(Photo: Pixabay)
Pixabay
  • There was promising news on Pfizer's vaccine candidate, while still being trialled, it showed 90% effectiveness
  • Russia's health ministry also later said its Sputnik V candidate was more than 90% effective
  • Critical Phase 3 trials of another leading vaccine candidate have started in South Africa

There was promising news on the Covid-19 vaccine front on Monday, both internationally and locally - much needed after global cases recently went past the 50 million mark.

US pharmaceutical giant Pfizer, in partnership with Germany's BioNtech were the first drugmakers to release successful data from a large-scale clinical trial of a coronavirus vaccine.

Reuters reported Pfizer as saying that Monday its experimental Covid-19 vaccine was more than 90% effective.

The companies said they have so far found no serious safety concerns and expect to seek US authorisation this month for emergency use of the vaccine.

If authorised, the number of doses will initially be limited and many questions remain, including how long the vaccine will provide protection. However, the news provides hope that other Covid-19 vaccines in development may also prove effective.

"Today is a great day for science and humanity," Albert Bourla, Pfizer's chairperson and chief executive, said.

"We are reaching this critical milestone in our vaccine development program at a time when the world needs it most with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen."

Pfizer expects to seek broad US authorisation for emergency use of the vaccine for people aged 16 to 85. To do so, it will need two months of safety data from about half the study's 44 000 participants, which his expected late this month.

"I'm near ecstatic," Bill Gruber, one of Pfizer's top vaccine scientists, said in an interview. "This is a great day for public health and for the potential to get us all out of the circumstances we're now in."

Last for at least a year

BioNTech's co-founder and chief executive said he was optimistic that the protective effect of its experimental Covid-19 vaccine, co-developed with Pfizer, would last for at least a year.

"We should be more optimistic that the immunisation effect can last for at least a year," CEO Ugur Sahin told Reuters.

While it was not yet known how long the protection would last, research on recovered patients and earlier findings on their vaccine led him to believe protection would not be short-lived.

READ | Leading Covid-19 vaccine candidate to be manufactured in SA

The US pharmaceutical giant said the interim analysis was conducted after 94 participants in the trial developed Covid-19, examining how many of them had received the vaccine versus a placebo.

The company did not break down exactly how many of those who fell ill received the vaccine. Still, over 90% effectiveness implies that no more than 8 of the 94 people who caught Covid-19 had been given the vaccine, which was administered in two shots about three weeks apart.

The efficacy rate is well above the 50% effectiveness required by the US Food and Drug Administration for a coronavirus vaccine.

To confirm the efficacy rate, Pfizer said it would continue the trial until there are 164 Covid-19 cases among participants. Given the recent spike in US infection rates, that number could be reached by early December, Gruber said.

The data have yet to be peer-reviewed or published in a medical journal. Pfizer said it would do so once it has results from the entire trial.

Synthetic genes

The Pfizer and BioNTech vaccine uses messenger RNA (mRNA) technology, which relies on synthetic genes that can be generated and manufactured in weeks, and produced at scale more rapidly than conventional vaccines.

Moderna, whose vaccine candidate employs similar technology, is expected to report results from its large-scale trial later this month.

The mRNA technology is designed to trigger an immune response without using pathogens, such as actual virus particles.

Russia's Sputnik V 'also more than 90% effective'

Also on Monday, a representative of the Russian health ministry said its Sputnik V vaccine against Covid-19 was more than 90% effective, citing data collated from vaccinations of the public rather than from an ongoing trial, Reuters reported.

"We are responsible for monitoring the effectiveness of the Sputnik V vaccine among citizens who have received it as part of the mass vaccination programme," Oksana Drapkina, director of a research institute under the health ministry, said in a statement.

"Based on our observations, it is also more than 90%. The appearance of another effective vaccine - this is good news for everyone," Drapkina said.

Russia is rolling out the vaccine for domestic use despite the fact that late-stage trials have not yet finished.

Earlier on Monday, Alexander Gintsburg, director of Moscow’s Gamaleya Institute which developed the Russian vaccine candidate, said he welcomed the Pfizer news.

“In the near future we expect to publish interim results of the post-registration trial of the vaccine Sputnik V, the so-called Phase III trials. I am sure that its effectiveness level will also be high,” he said.

Russia is gearing up to publish preliminary results of an ongoing large-scale human trial, known as Phase III, this month. It is testing the vaccine on 40 000 people in Moscow.

Johnson & Johnson vaccine candidate in Phase 3 trials in SA

Meanwhile, in South Africa, Johnson & Johnson has commenced its Phase 3 ENSEMBLE trial of its investigational Janssen Covid-19 vaccine, also known as Ad26.COV2.S, in the country.

Health24 reported that the first South African ENSEMBLE participants were dosed last week Friday. The study is currently ongoing in the US, Brazil, Chile, Colombia, and Argentina. 

According to the company, the global study is a randomised, double-blind, placebo-controlled clinical trial that will evaluate the safety and efficacy of a single vaccine dose versus placebo in up to 60 000 adults 18 years old and older.

The trial will also include significant representation from those over the age of 60, as well as those with and without comorbidities associated with an increased risk of severe Covid-19.

The vaccine candidate is included in the World Health Organization’s (WHO) latest list, dated 3 November, of the most viable candidate vaccines to go into human clinical trials, and uses a technology that has a long safety record in vaccines for other diseases.

Results from the initiation of the ENSEMBLE trial showed positive interim results, and was published in medRxiv in September 2020.

“Built on a legacy of purpose-driven actions and a commitment to diversity and inclusion, Johnson & Johnson aims to achieve broad representation of participants, including older adults and ethnically diverse populations in the implementation of its Covid-19 Phase 3 trial programme,” the release states.

In South Africa, the trial will take place across approximately 31 trial sites in locations with high rates of Covid-19 infections, including Gauteng, North West, Eastern Cape, Western Cape, Limpopo, Mpumalanga, and the Free State.

The company explained that these sites were determined in close collaboration with local health authorities, and took into account current disease prevalence, population demographics and regulatory authorities’ requirements.

*Additional reporting by Health24

Image credit: Getty Images

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