Covid-19 roundup: Novavax says vaccine shows 'broad cross-reactivity' against Omicron; France cancels order on Merck’s antiviral pill — report
Novavax said Wednesday that initial data suggest its Covid-19 vaccine demonstrated “broad cross-reactivity against Omicron and other circulating variants” after two doses — though neutralization was around 4-fold lower against Omicron compared to the original strain.
As a result, the company says it’s working on an Omicron-specific vaccine and plans to launch clinical studies in the first quarter of 2022.
“In the midst of an evolving pandemic, NVX-CoV2373 showed strong immune responses against Omicron and other circulating variants,” R&D president Gregory Glenn said in a statement. “We are encouraged that boosted responses against all variants were comparable to those associated with high vaccine efficacy in our Phase 3 clinical trials, suggesting that NVX-CoV2373 can play an important role in the ongoing fight against new variants.”
Immune responses increased following a third dose at six months, with researchers noting a 9.3-fold boost in anti-spike IgG titers against Omicron compared to peak responses seen after the two-dose regimen.
After facing multiple delays in the US (for which the company at one point blamed supply shortages and a regulatory manufacturing issue related to one of their assays), Novavax finally won conditional marketing authorization for its Covid-19 shot in Europe earlier this week.
CEO Stanley Erck told Yahoo Finance Live on Tuesday that the company is ready to file for an EUA in the US, and would do so “within the next few days.”
France cancels order on Merck’s antiviral pill — report
A Merck spokesperson told Reuters that France’s planned purchase didn’t take place after the country’s health authority rejected the pill over growing concerns about efficacy and the impact of the Omicron variant. The country had pre-ordered enough doses to treat 50,000 patients.
The FDA authorized the Ridgeback Biotherapeutics-partnered drug, called molnupiravir, on Thursday. The US could have about 400,000 courses available in the next few days, and by the end of January, the US government expects to have about 3 million courses, which is the entire order that the US made.
Merck had originally said molnupiravir, reduced the risk of death and hospitalizations by 50%. Then in late November, the company came back with updated data that suggested molnupiravir only cut the risk by about 30% compared to placebo.
Last month, the FDA’s Antimicrobial Drugs Advisory Committee voted 13-10 in favor of the pill’s benefits outweigh the risks for adults within 5 days of developing Covid symptoms.
Yesterday, US regulators signed off on Pfizer’s Covid-19 pills, made up of nirmatrelvir tablets and ritonavir tablets, co-packaged for oral use.
Pfizer’s pill, known as Paxlovid, proved to reduce the relative risk of hospitalization or death by 89% (within three days of symptom onset) and 88% (within five days of symptom onset) compared to placebo in a trial of more than 2,000 people.
“I don’t think you would find anyone who would prefer the Merck pill to the Pfizer pill, given the data evident so far,” Walid Gellad, a professor of medicine at the University of Pittsburgh, told Endpoints News.
New study suggests Sinovac’s vaccine does not protect against Omicron
A new study conducted in China found that two doses and a booster of Sinovac’s vaccine, dubbed CoronaVac, did not produce adequate levels of protective antibodies against the Omicron variant.
The study, conducted by the University of Hong Kong and the Chinese University of Hong Kong, also found that two doses of the Pfizer/BioNTech vaccine, Comirnaty, produced poor antibody responses against Omicron. However, a third dose of Comirnaty given to those who received two doses of either Comirnaty or CoronaVac did produce protective levels, according to a news release by the University of Hong Kong.
“Those who had received two doses of either Comirnaty or CoronaVac should get a third dose of Comirnaty vaccine around six months after their second dose of vaccine to achieve optimal protection against Omicron variant,” professor Malik Peiris said in a statement.
Just a week ago, Sinovac claimed that a third shot of CoronaVac was 94% effective against Omicron, according to a report by Nikkei Asia.
CoronaVac was one of the first vaccines authorized for emergency use by the Chinese government, snagging an OK back in July 2020, an unnamed official told Reuters.
Sinovac has touted mixed results in the past, with Brazil’s Butantan Institute announcing a 78% efficacy rate back in January, then correcting that figure to 50.4% less than a week later. In February, trial results from Brazil and Turkey suggested CoronaVac prevented 50.65% of all Covid-19 cases, 83.70% of cases requiring medical treatment, and 100% of hospitalizations, and severe or fatal cases 14 days after the second dose was administered.
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