Novavax jab effective against variants

A novel coronavirus vaccine from United States biotechnology company Novavax has demonstrated 89.3 percent efficacy at protecting against infection in a United Kingdom trial, according to interim study data.

The fact that a more transmissible variant of the virus that was first identified in the UK was circulating during the trial involving 15,000 people suggests the vaccine, called NVX-CoV2373, is effective against it.

Based on analysis of samples from infected trial participants, Novavax said its vaccine was 95.6 percent effective against the original COVID-19 strain, and 85.6 percent effective against the variant. In general, drug regulators will not authorize a vaccine with less than 50 percent efficacy.

"These are spectacular results," said Clive Dix, who is chairman of the UK's vaccine task force. "The efficacy shown against the emerging variants is also extremely encouraging."

Novavax also posted interim results from a trial in South Africa, which showed the vaccine led to 60 percent reduced risk of illness from COVID-19.

In that trial of 6,000 participants, 93 percent of those that tested positive for the virus had been infected by a variant first identified in South Africa, suggesting that while the Novavax vaccine does not provide complete protection against the strain, its efficacy is still significant.

This field trial data is especially encouraging since lab analysis from other vaccine makers had suggested that available treatments could be far less potent against the strain identified in South Africa.

Shabir Maddi, who is principal investigator in the Novavax COVID-19 vaccine trial in South Africa, said the Novavax vaccine may prove a valuable tool in preventing illness from the "highly worrisome variant "circulating in South Africa, which has also been found in other countries including the US and the UK.

"This is the first COVID-19 vaccine for which we now have objective evidence that it protects against the variant dominating in South Africa," said Maddi.

Novavax estimates it has the capacity to manufacture 2 billion doses in 2021. The UK has ordered 60 million doses of the vaccine, which can be manufactured on British soil. If the vaccine receives approval from UK regulators, the first doses should be ready by the second half of this year.

In January, Australia finalized a deal for 51 million doses, while the US made an initial order of 100 million doses last year. New Zealand has an agreement for 10.7 million doses, and Canada recently finalized a deal for 52 million doses, with an option for an additional 24 million.

The current vaccine frontrunners on the market either rely on weakened viral particles or messenger RNA to provoke an immune response, but the Novavax treatment works differently.

NVX-CoV2373 is a protein subunit vaccine, which means it introduces a lab-made version of the molecule that the virus uses to enter cells, which is known as the spike protein. By familiarizing the body with this molecule, the vaccine helps the immune system form a response to initial exposure.

The jab requires two doses taken three weeks apart, and can be stored at normal refrigeration temperatures, providing an advantage over shots like the Pfizer vaccine that require ultra-cold storage.