This photo illustration shows a silhouette of a man holding a medical syringe and a vial in front of the Novavax logo on a screen.
Cezary Kowalski | Lightrocket | Getty pictures
The Centers for Disease Control and Prevention’s independent advisers recommended Novavax’s two-dose Covid-19 vaccine as a primary series for adults on Tuesday, one of the final steps before pharmacies can begin administering the shots.
The CDC committee voted unanimously to recommend the vaccine to people aged 18 and older after reviewing the safety and effectiveness of the shots during an hour-long public meeting on Tuesday. CDC Director Dr. Rochelle Walensky may give the green light for vaccinations to begin as soon as this week.
Novavax shares rose 12% following a recommendation from the CDC panel.
Walensky’s endorsement will complete a two-year journey for Novavax, one of the early participants in the US race to produce a vaccine to protect against Covid-19. The small biotechnology company in Maryland received $ 1.8 billion in taxpayers’ money from Operation Warp Speed, but struggled to get the production base in place and eventually fell behind Pfizer and Moderna.
Novavax’s vaccine will enter the United States at a time when more than three-quarters of American adults, 77%, are now fully vaccinated with Pfizer, Moderna and to a much lesser extent Johnson & Johnson’s shots, according to CDC data.
US health officials and Novavax executives have said the vaccine will provide another option for people who do not want to take Pfizer and Moderna’s shots. Between 26 million and 37 million adults are still unvaccinated in the United States, according to CDC data, but it is unclear how many of these people will choose to take Novavax’s vaccine.
The Biden administration has secured 3.2 million doses of Novavax’s vaccine so far, according to the Health and Human Services Department.
“The primary target population for Novavax will be 10% to 13% of those unvaccinated,” said Dr. Oliver Brooks, a committee member and chief medical officer at Watts HealthCare Corporation in Los Angeles.
“I understand that we are really focused on that population with the hope that maybe this protein subunit vaccine will change them from being unvaccinated to vaccinated,” Brooks said.
Efficiency and safety
Novavax shots were 90% effective in preventing disease in general and 100% effective in preventing serious illness when the alpha variant of Covid was dominant, according to data from clinical trials. The company has not published data on the true effectiveness of the shots against omicron and its sub-variants.
However, Novavax’s vaccine appears to elicit a strong immune response against omicron and its subvariants, suggesting that it is effective against the variant. The company’s immune response data against omicron impressed members of the Food and Drug Administration’s vaccine committee last month.
The FDA warned in a fact sheet for healthcare professionals that Novavax’s vaccine appears to be at risk for myocarditis called myocarditis. FDA officials reported four cases of myocarditis and pericarditis – swelling of a membrane surrounding the heart – from Novavax’s clinical study in young men aged 16 to 28.
Pfizer and Moderna’s shots also pose an increased risk of myocarditis for young boys and young men after the second dose. The CDC has found that Covid infection carries a greater risk of heart inflammation than vaccination with Pfizer or Moderna’s shots. Myocarditis is usually caused by viral infections.
Novavax’s vaccine uses a different platform than Pfizer’s and Modern’s shots. The Novavax vaccine is based on protein technology already used in HPV and hepatitis B vaccines.
The company produces inactive copies of the virgin spike protein by inserting genetic code into an insect virus that infects moth cells. The spike copies are harvested and purified from these cells for the vaccine.
The nail protein is the mechanism the virus uses to invade human cells. The spike copies in the vaccine prepare the body’s immune system to produce antibodies that block the virus from invading human cells. Novavax’s vaccine also has an additional ingredient, called an adjuvant, which is derived from the bark of a South American tree to produce a broader immune response to fight the virus.
Pfizer and Moderna’s vaccine, on the other hand, use messenger RNA technology. Their shots deliver messenger RNA to human cells, which then produce inactive copies of the spike protein to generate an immune response to fight the virus. Pfizer and Moderna’s shots are the first mRNA vaccines to receive FDA approval.
Novavax’s shots are also stored at normal refrigerator temperatures, while Pfizer’s and Moderna’s shots require minus cold.
Although the FDA has repeatedly authorized Pfizer’s and Modern’s shots as safe and effective vaccines for all age groups in the United States, health authorities have struggled to convince millions of skeptics to take the shots.
Autumn vaccine change
The United States plans to fine-tune the vaccines to target the more transmissible BA.4 or BA.5 omicron subvariants, which are now dominant, ahead of an expected autumn vaccination campaign. Covid vaccines are less effective at preventing omicron infection due to the many mutations in the variant, but they still generally protect against serious illness.
US health authorities believe that changing the formula for the vaccines to target omicron variants, as well as the original strain that appeared in Wuhan, China in 2019, will provide more lasting protection against the virus this fall.
Novavax’s vaccine, like all currently approved Covid shots, is based on the original strain of the virus that first appeared in China. Like Pfizer and Moderna, Novavax develops vaccines targeting the omicron variant, but company executives have said it is not clear they need to roll out an updated shot because the company’s current vaccine triggers a broad immune response to the variant.
The CDC and FDA have not approved the mixing and matching of Novavax’s vaccine with Pfizer’s and Moderna’s shots as a booster. Novavax has said it plans to ask the FDA to approve a booster shot of the vaccine.