Novavax faces high-risk FDA review this week that will decide the fate of its Covid vaccine in the US

In this photographic illustration, the Food and Drug Administration (FDA) and Novavax logos are seen behind a syringe and medical vials.

Pavlo Gonchar | LightRocket | Getty Images

Novavax’s Covid-19 vaccine will face scrutiny from the Food and Drug Administration’s independent immunization experts this week, a crucial step on the road to US regulatory clearance two years after the Maryland biotech company received taxpayer funding to develop the vaccines.

The committee of vaccine experts will assess the safety of Novavax vaccines and their effectiveness in preventing Covid during a full-day public meeting on Tuesday. If the committee approves the vaccine, the FDA will almost certainly give the green light to ship doses from Novavax’s manufacturing partner, the Serum Institute of India, to the US. The company’s vaccines have been authorized in 41 countries outside the US, including Australia, Canada, and the European Union.

“We are very confident in the data we present,” said Novavax spokeswoman Silvia Taylor. “If past success is an indication of future success, we feel pretty good,” Taylor said.

Novavax was an early entrant in the US government’s 2020 race to develop a Covid vaccine, receiving $1.8 billion from Operation Warp Speed. However, the small biotech company has faced an uphill battle to grow its manufacturing capacity and clinical trial data. he came after Pfizer and Moderna, which developed their injections at breakneck speed, are now the dominant players in the US vaccination campaign.

When the pandemic began in 2020, Novavax had 100 employees and no manufacturing capacity, said John Trizzino, the company’s chief commercial officer. Today, the company has the capacity to produce 2 billion doses a year, said Trizzino.

Novavax injections are based on protein technology used for decades in hepatitis B and HPV vaccines. The Pfizer and Moderna vaccines, on the other hand, were the first vaccines using messenger RNA technology to receive FDA approval. Novavax believes it can target people who haven’t been vaccinated yet, because they prefer to receive a vaccine based on technology that has a longer track record, Taylor said.

Protein vs mRNA

The Pfizer and Moderna shots rely on messenger RNA to turn human cells into factories that produce copies of the Covid spike protein to induce an immune response that fights the virus. The spike is the part of the virus that latches onto and invades human cells.

Novavax, on the other hand, produces the peak of the virus outside the human body. The genetic code for the spike is put into a baculovirus that infects the moth’s cells, which then produce copies of the spike which are then purified and extracted. The spike copy, which cannot replicate or cause Covid, is injected into people inducing an immune response against the virus.

Medical director Filip Dubovsky said manufacturing the spike protein outside the human body allows the company to ensure the vaccine is configured in the most effective way to produce an immune response.

“We know exactly what we’ve done and we’ve tested it as part of the vaccine release process to make sure it’s in the right conformation,” Dubovsky said.

The vaccine also uses an adjuvant, a purified extract from the bark of a South American tree, to induce a broader immune response. The adjuvant has been used in licensed vaccines against malaria and shingles. The injections consist of 5 micrograms of the spike copy and 50 micrograms of the adjuvant.

Novavax vaccine effectiveness

Novavax’s two-dose vaccine for adults 18 years and older was 90% effective in preventing Covid-19 illness and 100% effective in preventing serious illness, according to the results of the company’s clinical trials in the US and Mexico. These results are as good as Pfizer’s and Moderna’s initial test results in 2020.

However, the pandemic and the public health response are in a very different place today than they were in 2020, which presents Novavax with immediate challenges if the FDA authorizes its vaccine. About 70% of people eligible for vaccination in the US have already received their first two doses, predominantly with injections from Pfizer or Moderna. And the world is now fighting the omicron variant, which is very different from the original strain of the virus that emerged in Wuhan, China, in late 2019.

Novavax’s adult trial was conducted from December 2020 to September 2021, before the omicron variant became dominant. There is no data available to assess Novavax’s effectiveness against omicron, which continues to mutate into more transmissible versions of the virus, according to FDA briefing documents published ahead of Tuesday’s committee meeting. However, FDA officials said the two-dose vaccine would likely provide significant protection against serious illness.

Novavax published a lab study in December that showed people given two doses had an immune response against omicron, although antibodies blocking the infection dropped about fourfold against the variant compared to the original strain of the virus. Wuhan. However, a booster boosted protective antibodies about 20-fold against the micron compared to the peak response of the first two doses against the Wuhan strain, according to the study data. The higher levels of antibodies suggest, though not guarantee, that a third dose would provide high levels of protection.

While the majority of the US population is already vaccinated, Novavax executives believe the company’s vaccines can play an important role as a booster for adults and as a primary vaccination for 12- to 17-year-olds. Currently, only Pfizer’s vaccine is available for teenagers, although the FDA will review Moderna’s vaccines for this age group on June 14. About 50% of adults have not yet received a third dose and 40% of teenagers are not fully vaccinated, according to the Centers for Disease Control and Prevention.

To be clear, the FDA committee is only reviewing Novavax’s two-dose primary series for adults on Tuesday. However, Novavax plans to ask the FDA to authorize a third dose for adults, as well as the primary series for teens ages 12 to 17, if the agency releases two doses for adults, Taylor said. Novavax is also studying a third shot for teenagers.

Heart inflammation concerns

The most common side effects of Novavax injections were pain at the injection site, fatigue, headache, and muscle aches, according to FDA briefing documents. However, four participants developed cardiac inflammation, myocarditis or pericarditis, or abnormal chest pain after receiving the Novavax injections, according to the FDA. All of them were hospitalized for several days, although they recovered.

“These events raise concern for a causal association with this vaccine, similar to the documented association with COVID19 mRNA vaccines,” FDA officials said in the information documents. The second dose of the Pfizer and Moderna vaccines was associated with an increased risk of cardiac inflammation in young men and adolescents.

Novavax, in a statement, said there was not enough evidence to establish a causal relationship between the vaccine and heart inflammation. However, the company said it will continue to monitor myocarditis and pericarditis during its trials.

Autumn booster campaign

It is unclear how many doses of Novavax will be available in the US if the FDA authorizes the vaccine this week. Novavax initially agreed to provide the US with 100 million doses under its $1.8 billion Operation Warp Speed ​​contract, but some of the funding was used to support the company’s studies of third doses and vaccines for children.

Trizzino said an initial delivery of injections will be made in the weeks following FDA clearance without specifying an amount. Novavax and the US government have yet to reach an agreement on future orders, he said.

Trizzino said Novavax is looking at demand for a fall vaccination campaign in the US as public health officials expect another wave of Covid infection as people spend more time indoors when the weather changes. The FDA is considering moving all Covid vaccines to target the omicron variant before the fall to increase the effectiveness of vaccines against mild disease.

Novavax launched a clinical trial in late May to study a shot that targets only omicron and another that includes both Wuhan and omicron strains. However, the deadline for updating vaccines for the fall is short. The FDA’s independent experts are holding their second meeting on June 28 to discuss whether a strain change is necessary, which would leave Novavax and the other vaccine makers just a few months to manufacture updated injections.

Trizzino said the path to delivering vaccines based solely on the Wuhan strain or the omicron variant for the fall is relatively straightforward, but producing injections that include both strains is more challenging on a compressed schedule. While it’s unclear what the FDA will decide for the fall, Covid vaccines — whether based in Wuhan or omicron or both — will be needed well beyond this year, Trizzino said.

“This virus is not going away anytime soon,” Trizzino said. “There is a high degree of certainty that there will be some sort of annual revaccination in the near future,” he said.

CNBC Health and Science

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