The NIH is beginning trials with COVID boosters to combat future variants

Enlarge / A vial of the current Moderna COVID-19 vaccine.

Mild or not, multiple SARS-CoV-2 variants are unavoidable. To avoid blips in our pandemic playoffs, researchers at the National Institutes of Health on Thursday announced the start of a complex Phase II clinical trial to find the best COVID-19 booster cure to protect against variants emerging in the wake of omicron.

“We look beyond the omicron variant to determine the best strategy to protect against future variants,” Anthony Fauci, director of the NIH’s National Institute of Allergy and Infectious Diseases, said in a statement. “This trial will help us understand whether we can use prototype and variant vaccines alone or together to alter immune responses to cover existing and new COVID-19 variants.”

So far, evidence suggests that current vaccines – which are based on an early version of SARS-CoV-2 isolated in Wuhan, China – may provide protection against most of the variants swept across the globe so far. However, current vaccines have struggled with omicron, an ultra-transmissible variant that is the most divergent variant yet. As such, researchers are cautious that an omicron-specific vaccine alone will not generate broad protection against any future variant that may be more closely related to previous variants – such as beta, a variant first discovered in South Africa in 2020, which is suspected to be more serious. than previous variants, and delta, a highly transmissible variant that swept through the United States before the advent of the omicron.

To generate the broadest, strongest protection against any form that SARS-CoV-2 takes next, NIH researchers are trying different combinations. To be precise, the experiment will set six different booster cures against each other:

  1. Current booster: The currently used 50 micrograms Modern booster (mRNA-1273, aka Spikevax)
  2. Beta-omicron combo booster: A single 50 microgram booster containing two experimental vaccines, one targeting the beta variant (mRNA-1273,351) and the other targeting the omicron variant (mRNA-1273,529)
  3. Two-dose beta-omicron combo booster: Two 50-microgram vaccinations given at two-month intervals containing beta-omicron combination syringe (mRNA-1273,351 and mRNA-1273,529)
  4. Delta-omicron combo booster: A single 50-microgram booster containing two experimental vaccines, one targeting the delta variant (mRNA-1273.617.2) and the other omicron (mRNA-1273.529)
  5. Omicron booster: A single 50 microgram shot of the experimental omicron vaccine (mRNA-1273,529)
  6. Current omicron combo booster: A single 50 microgram shot containing Spikevax and the experimental omicron-targeted vaccine (mRNA-1273,529)

Dr. Nadine Rouphael, from Emory’s Vaccine Center, and Dr. Angela Branche, of the University of Rochester Medical Center in New York, is leading the trial, which will be conducted at 24 clinics in a dozen states and Washington, DC. They aim to enroll 600 adults who have received a two-dose primary vaccine series and a booster of either mRNA vaccines or a mixture. The trial could include individuals who also had a previous SARS-CoV-2 infection, although individuals who became infected within 16 weeks of starting the trial would be excluded. Trial participants will be randomly assigned to one of the six regimens tested.

The analysis will be complex. The researchers will closely monitor the immune reactions that develop after the vaccinations. These reactions can be affected not only by the test regimens, but also by which vaccines the participants had in the past, as well as any previous infections.

While the trial will follow participants for 12 to 14 months, Rouphael and Branche aim to have the first results in August 2022. This means the results could inform fall-strengthening campaigns that federal regulators have said they are considering. This week, the FDA and CDC approved second booster dosing of the current vaccine for people aged 50 and over, as well as those with compromised immune systems. But in a press briefing Wednesday, the FDA’s top vaccine regulator, Peter Marks, suggested the agency expects to offer additional boosters to the entire population this fall. That time frame would be consistent with when people usually roll up their sleeves for seasonal flu vaccinations, and it could also help counteract the possibility of a similar seasonal increase in COVID-19.

Leave a Comment