The Food and Drug Administration’s independent group of vaccine experts voted Tuesday 19-2 to recommend new Covid-19 vaccinations aimed at the omicron variant this fall, when public health officials expect a new wave of infections.
This is the first time the panel has proposed that vaccine manufacturers modify injections to target a different variant. The FDA will likely accept the committee’s recommendation and authorize a vaccine change. However, the panel did not make a recommendation as to which omicron subvariant should target the shots.
Pfizer, Moderna, Novavax and Johnson & Johnson developed their vaccines against the original Covid strain that first emerged in Wuhan, China, in 2019. But as the virus has evolved rapidly throughout the pandemic, Vaccines have become less effective at protecting against mild infections and diseases, although they generally still protect against serious diseases.
A health worker prepares a syringe with the Modern COVID-19 vaccine at an emerging vaccination site operated by SOMOS Community Care during the COVID-19 pandemic in Manhattan, New York City, on January 29, 2021.
Facebook Facebook logo Sign in with Facebook to connect with Mike Segar Reuters
Vaccines target the cutting-edge protein the virus uses to invade human cells. However, traits have trouble recognizing and attacking the ear as more mute than the original version of the virus. The omicron variant is the most dramatic example to date with over 30 mutations. This is one of the central reasons why omicron caused such a massive wave of infections last winter even though masses of people were fully vaccinated.
Autumn reinforcement campaign
Omicron continues to mutate into more contagious subvariants. Dr. Peter Marks, who heads the FDA’s vaccine division, said the U.S. will face an outbreak of Covid this fall and winter as the virus evolves, the vaccine’s immunity declines and people spend more time indoors where Covid can spread much easier than outdoors.
“For that reason, we need to seriously consider a reinforcement campaign this fall to help protect ourselves,” Marks told the committee. “The better the combination of the vaccine with the circulating strain, we believe may correspond to an improvement in vaccine efficacy and potentially to better durability of protection.”
Justin Lessler, an epidemiologist at Chapel Hill University in North Carolina, said an additional 95,000 people could die in the United States by Covid in March 2023 in the most optimistic projections of a team of scientists who are developing models of the trajectory of the pandemic. In the most pessimistic scenario, 211,000 people could die from the virus in March next year, he said. However, Lessler warned that there is a lot of uncertainty in these projections.
Three doses of current vaccines are only 19% effective in preventing omicron infection among adults 18 years and older 150 days or more after administration, according to data presented by the Centers for Disease Control and Prevention. This low protection against infection is probably due to the evolution of omicrons toward the more contagious BA.2 and BA.2.12.1 subvariants, said Dr. Ruth Link-Gelles, a CDC official. According to the data, a third dose was 55% effective in preventing the hospitalization of these subvariants among adults 120 days or more after receiving the vaccine.
Limited data, limited time
The virus is evolving so fast that vaccine companies are struggling to keep up. Pfizer and Moderna developed their omicron features against the original version of the variant, BA.1. However, BA.1 no longer circulates in the US. A more contagious omicron subvariant, BA.2, became dominant during the spring. Omicron BA.4 and BA.5 subvariants are gaining ground rapidly in the U.S. and are poised to become dominant, Marks said.
Pfizer and Moderna presented data, based on small studies of several hundred people, showing that their omicron traits significantly increased the immune response against omicron BA.1 compared to the original traits targeted to the strain of virus that emerged in China. However, the updated features did not work as well against BA.4 and BA.5, although the immune response was still strong. No data are available on the real-world effectiveness of updated injections, although the strength of the immune response is generally considered an indication of how much protection the injections will offer against the disease.
But committee member Dr Paul Offit said it was unclear whether the immune response data would translate into meaningful protection.
“I just think we need a higher standard for protection and what they give us, I think it’s awkwardly scarce,” Offit, an infectious disease expert at Philadelphia Children’s Hospital, said of the data presented at the meeting.
FDA panel members seemed to agree that it would be best to target omicron BA.4 or BA.5. But this could create logistical challenges for vaccine companies because they have focused on BA.1. The process of making a different subvariant would take about three months.
Panel member Dr. Mark Sawyer said the FDA risked being further delayed with the evolution of the virus if it did not act soon.
“Given this state of evolution, we’ll be behind the ball eight if we expect more,” said Sawyer, a professor of pediatrics at the University of California at San Diego.
Novavax presented data showing a booster dose of its current vaccine, which targets the original virus strain, produced a strong immune response against omicron subvariants. Dr. James Hildreth, a temporary member of the committee, said he was very impressed with the Novavax data and encouraged the FDA to quickly authorize the vaccine for use in the U.S. agency.
Panel member Dr. Cody Meissner said he was concerned that there is not enough safety data on how changing the composition of vaccines could affect heart inflammation or myocarditis as a side effect. Current injections of Pfizer and Moderna have been associated with a high risk of myocarditis in adolescent boys.
“We need more studies or research on what the association is with vaccines and myocarditis,” Meissner said.
Marks said it is crucial to make an early decision on whether vaccines are updated, so that manufacturers have time to produce vaccinations in time for the fall. However, Congress has not appropriated money because the U.S. is buying additional vaccines. The White House has warned that without more funding, the U.S. could have to ration up fall vaccinations for people at higher risk, such as the elderly.
Dr. Ashish Jha, who coordinates the response to Covid-19 in the United States, said other countries have already entered into negotiations with vaccine manufacturers to get updated vaccinations. The White House has secured $ 5 billion in funding to start talks with companies while the administration expects more money from Congress. The $ 5 billion the White House is using for vaccines was originally intended for Covid testing and protective equipment, meaning there is now less money for these other crucial tools to fight the pandemic.
CNBC Health and Science
Read CNBC’s latest global coverage of the Covid pandemic: