“Policy regarding future doses requires continuous evaluation of the epidemiology of Covid-19 and the effectiveness of vaccines, including the impact of time and variants, and the ability of doses to improve this protection,” said CDC’s Dr. Sara Oliver, an epidemic intelligence officer with the Division of Viral Diseases, said at the meeting.

Before recommending future doses of Covid-19 vaccines, Oliver said, committee members should assess the number of recent cases in the country, hospitalization rates, vaccine effectiveness — including whether it’s declining with the weather – and the impacts of circulating coronavirus variants.

As the virus continues to evolve, “the evolution of Covid vaccines will be significant,” including vaccine platforms, Oliver said.

The Covid-19 vaccines people will receive in the future could be completely different formulations from those given now, which are based on the original version of the virus that emerged in late 2019.

The next booster could be a new vaccine

Some companies, including Pfizer/BioNTech and Moderna, are developing variant-specific vaccines that could target any circulating coronavirus strain when that booster might be needed. Pfizer and Moderna are working on vaccines that would specifically protect against the Omicron variant, though it’s unclear whether one is needed.

How long it takes to make a vaccine — once it’s decided to change or update that vaccine’s composition — is also unclear.

But for the vaccines now available, a decision to modify them should be made “by early summer at the latest” if a vaccination campaign were to be necessary in the fall, said Dr Doran Fink, deputy director of the U.S. Food and Drug Administration’s Vaccine Division, said at Wednesday’s meeting.

Pfizer CEO Albert Bourla said the company also hopes to manufacture a vaccine that will protect against Omicron as well as all other variants of the coronavirus.

The goal is to create “something that can protect for at least a year,” Bourla told CBS in March. “And if we’re able to achieve that, then I think it’s very easy to follow and remember so that we can really get back to the path. [we] I lived.”

Moderna announced on Tuesday that its first bivalent Covid-19 booster candidate – which combines elements of the current vaccine with updates based on the beta variant – induced higher antibody responses against all variants of concern than the booster. Original company covid-19.

Moderna has developed updated booster candidates to target emerging coronavirus variants, and it also has monovalent (based on a single strain of virus) candidates in the works.

Its first bivalent booster candidate, called mRNA-1273.211, was well tolerated, the company said, and a preprint study published last week on the Research Square online server found it elicited antibody responses. higher than Moderna’s current recall against the original coronavirus and the Beta, Delta, and Omicron variants.

The Moderna scientists wrote in the study that the safety profile of a 50 microgram dose of the booster candidate mRNA.1273.211 was comparable to that of the current 50 microgram dose of the vaccine.

The study has not been peer reviewed or published in a professional journal.

Despite the booster candidate’s superiority over the original vaccine, Moderna CEO Stephane Bancel said in a press release on Tuesday that a separate bivalent candidate combining the current vaccine with an Omicron-specific vaccine is still the lead candidate for the company to possibly roll out this fall.

Two-in-one influenza-Covid vaccines in development

Moderna and biotech company Novavax are also working on two-in-one combination vaccines that can offer protection against influenza and Covid-19.

Novavax asks the FDA for emergency use authorization for its coronavirus vaccine

Novavax’s Covid-19 vaccine is not licensed in the United States, but the company filed for emergency use authorization with the US Food and Drug Administration in January.

In the meantime, it continues to study the vaccine that combines its NVX-CoV2373 Covid-19 vaccine and its quadrivalent influenza vaccine candidate. On Wednesday, Novavax announced that the combination vaccine was “well tolerated” and induced an immune response in participants in a phase 1/2 clinical trial.

Novavax scientists evaluated the safety of different formulations of the vaccine as well as the immunological responses they elicited. Data from the trial showed that the combination vaccine induced immune responses comparable to those induced when the flu vaccine and the Covid-19 vaccine are given separately.

A fourth Covid-19 hit could be recommended this fall, as officials

The data also showed that the combination vaccine’s safety profile was consistent with the stand-alone safety profiles of the influenza and Covid-19 vaccines. Serious adverse events during the trial were “rare and none were assessed as being related to the vaccine,” the company said.

“We continue to assess the dynamic public health landscape and believe there may be a need for recurring reminders to address both COVID-19 and seasonal influenza,” said Dr. Gregory Glenn, President. of Novavax research and development, in a press release. “We are encouraged by this data and the potential path forward.”

Novavax announced that the data supports advancing the study to a Phase 2 trial, which is expected to begin by the end of the year.

For now, CDC vaccine advisers plan to continue discussions on how to be “more proactive than reactive” regarding the future need for Covid-19 vaccinations, Dr. Matthew Daley said, chairman of the committee’s vaccine task force and senior researcher at the Kaiser Permanente Institute for Health Research, said at Wednesday’s meeting.

“These are our marching orders,” Daley told his fellow committee members.

“We had a lot of work before, but then we want to take what we heard in this meeting and present it to the working group and discuss each of these issues,” he said. “Given the unpredictability of the pandemic, we’ve had to be reactive, but I think this is a place where we can also try to be more proactive.”